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Helminths (worms) are one of the most successful organisms in nature given their ability to infect millions of humans and animals worldwide.,Their success can be attributed to their ability to modulate the host immune response for their own benefit by releasing excretory-secretory (ES) products.,Accordingly, ES products have been lauded as a potential source of immunomodulators/biotherapeutics for an array of inflammatory diseases.,However, there is a significant lack of knowledge regarding the specific interactions between these products and cells of the immune response.,Many different compounds have been identified within the helminth “secretome,” including antioxidants, proteases, mucin-like peptides, as well as helminth defense molecules (HDMs), each with unique influences on the host inflammatory response.,HDMs are a conserved group of proteins initially discovered in the secretome of the liver fluke, Fasciola hepatica.,HDMs interact with cell membranes without cytotoxic effects and do not exert antimicrobial activity, suggesting that these peptides evolved specifically for immunomodulatory purposes.,A peptide generated from the HDM sequence, termed FhHDM-1, has shown extensive anti-inflammatory abilities in clinically relevant models of diseases such as diabetes, multiple sclerosis, asthma, and acute lung injury, offering hope for the development of a new class of therapeutics.,In this review, the current knowledge of host immunomodulation by a range of F. hepatica ES products, particularly FhHDM-1, will be discussed.,Immune regulators, including HDMs, have been identified from other helminths and will also be outlined to broaden our understanding of the variety of effects these potent molecules exert on immune cells.

The expression of T regulatory cells (Foxp3), regulatory (interleukin [IL]-10 and transforming growth factor beta [TGF-β]) and proinflammatory (tumor necrosis factor alpha [TNF-α] and interleukin [IL]-1β) cytokines was quantified using real time polymerase chain reaction (qRT-PCR) in the liver of sheep during early stages of infection with Fasciola hepatica (1, 3, 9, and 18 days post-infection [dpi]).,Portal fibrosis was also evaluated by Masson’s trichrome stain as well as the number of Foxp3+ cells by immunohistochemistry.,Animals were divided into three groups: (a) group 1 was immunized with recombinant cathepsin L1 from F. hepatica (FhCL1) in Montanide adjuvant and infected; (b) group 2 was uniquely infected with F. hepatica; and (c) group 3 was the control group, unimmunized and uninfected.,An overexpression of regulatory cytokines of groups 1 and 2 was found in all time points tested in comparison with group 3, particularly at 18 dpi.,A significant increase of the number of Foxp3+ lymphocytes in groups 1 and 2 was found at 9 and 18 dpi relative to group 3.,A progressive increase in portal fibrosis was found in groups 1 and 2 in comparison with group 3.,In this regard, group 1 showed smaller areas of fibrosis than group 2.,There was a significant positive correlation between Foxp3 and IL-10 expression (by immunohistochemistry and qRT-PCR) just as between portal fibrosis and TGF-β gene expression.,The expression of proinflammatory cytokines increased gradually during the experience.,These findings suggest the induction of a regulatory phenotype by the parasite that would allow its survival at early stages of the disease when it is more vulnerable.

Current World Health Organization and national protocols recommend the ‘test and treat’ strategy for the management of uncomplicated malaria, to reduce over prescription of artemisinin-based combination treatment (ACT).,Therefore, adherence to these protocols varies in different sub-Saharan African countries and no information is available for Mozambique.,This study was conducted with the aim to evaluate the prescription practices of ACT in Mozambique.,Retrospective audit of medical records corresponding to the period between July and December 2011 was conducted in 22 health units across 11 provinces in Mozambique.,Two health units were selected per province according to availability of laboratory data (performing microscopy and rapid diagnostics testing-RDT or RDT only) and geographic setting (rural versus urban).,At each facility, demographic data, laboratory results (blood smear or RDT), and prescription of ACT were all collected from the existing records.,Between July and December 2011, a total of 61,730 cases were tested for malaria, of which 42.7 % (26,369/61,730) were positive.,A total of 35.361 patients were malaria negative, and ACT was prescribed to 72.0 % (25.448/35.361) of them.,Prescription of ACT to malaria negative patients was higher in the central region of the country as compared to the northern and southern (81.1 % in the central region versus 72.4 and 63.7 % in the northern and southern, respectively, p = 0.000) and in urban settings (88.7 % in rural versus 58.0 % in urban settings, p = 0.000).,Stock out of RDT was observed in six (27.3 %) of the health facilities.,When no RDT was available, patients were empirically treated with ACT.,Findings from this study demonstrate that health care worker’s adherence to the new guidelines for malaria treatment is poor in Mozambique and prescription of ACT to malaria negative patients remains very high.,Enhanced training and supervision activities, community education and external quality assurance might lead to significant improvements in the clinician’s adherence to the new guideline for malaria treatment in Mozambique.

In 2010, the World Health Organization revised guidelines to recommend diagnosis of all suspected malaria cases prior to treatment.,There has been no systematic assessment of malaria test uptake for pediatric fevers at the population level as countries start implementing guidelines.,We examined test use for pediatric fevers in relation to malaria endemicity and treatment-seeking behavior in multiple sub-Saharan African countries in initial years of implementation.,We compiled data from national population-based surveys reporting fever prevalence, care-seeking and diagnostic use for children under five years in 13 sub-Saharan African countries in 2009-2011/12 (n = 105,791).,Mixed-effects logistic regression models quantified the influence of source of care and malaria endemicity on test use after adjusting for socioeconomic covariates.,Results were stratified by malaria endemicity categories: low (PfPR2-10<5%), moderate (PfPR2-10 5-40%), high (PfPR2-10>40%).,Among febrile under-fives surveyed, 16.9% (95% CI: 11.8%-21.9%) were tested.,Compared to hospitals, febrile children attending non-hospital sources (OR: 0.62, 95% CI: 0.56-0.69) and community health workers (OR: 0.31, 95% CI: 0.23-0.43) were less often tested.,Febrile children in high-risk areas had reduced odds of testing compared to low-risk settings (OR: 0.51, 95% CI: 0.42-0.62).,Febrile children in least poor households were more often tested than in poorest (OR: 1.63, 95% CI: 1.39-1.91), as were children with better-educated mothers compared to least educated (OR: 1.33, 95% CI: 1.16-1.54).,Diagnostic testing of pediatric fevers was low and inequitable at the outset of new guidelines.,Greater testing is needed at lower or less formal sources where pediatric fevers are commonly managed, particularly to reach the poorest.,Lower test uptake in high-risk settings merits further investigation given potential implications for diagnostic scale-up in these areas.,Findings could inform continued implementation of new guidelines to improve access to and equity in point-of-care diagnostics use for pediatric fevers.

To perform environmental sampling and molecular identification of Paragonimus in endemic regions, which may help in minimizing transmission among humans.,Mountain crabs from the genus Potamiscus were collected and the encysted metacercariae were extracted and subjected to morphological identification, followed by animal inoculation in Sprague-Dawley (SD) rats.,After 112 days of infection, animals were killed and adult worms were extracted from lungs and muscles.,The morphology of adult worms was characterized by microscopy and molecular identification was done by polymerase chain reaction, followed by sequencing of cox1 and ITS2 genes.,Phylogenetic analysis was done by maximum parsimony method.,A total of 447 crabs were captured from the streams of Tongchang Town, Jinping County, Yunnan Province, China.,The infection rate was found to be 41% (186 out of 447 crabs).,The metacercariae of Paragonimus skrjabini was identified by the characteristics round or spherical encysted form measuring 410 to 460 × 400 to 460 µm.,After animal infection in SD rats, adults were presumptively confirmed to be P. skrjabini, which was also confirmed by gene amplification and sequence analysis of cox1 and ITS2 regions.,Paragonimus skrjabini clustered with previously reported P. skrjabini from Yunnan and Vietnam.,The confidence values of their branches were > 95%.,Phylogenetic analysis of the ITS2 region revealed two distinct clusters with distinct geographical grouping.,Phylogenetic analysis with the combined data sets reiterated the geographical grouping with P. skrjabini from Yunnan clustering with strains from Vietnam.,Metacercariae of P. skrjabini was discovered in freshwater crabs in Yunnan province, China, and the strains were phylogenetically related to P. skrjabini from Vietnam.

Paragonimus spp. (lung flukes) are among the most injurious foodborne helminths, infecting ∼23 million people and subjecting ∼292 million to infection risk.,Paragonimiasis is acquired from infected undercooked crustaceans and primarily affects the lungs but often causes lesions elsewhere including the brain.,The disease is easily mistaken for tuberculosis owing to similar pulmonary symptoms, and accordingly, diagnostics are in demand.,We assembled, annotated, and compared draft genomes of 4 prevalent and distinct Paragonimus species: Paragonimus miyazakii, Paragonimus westermani, Paragonimus kellicotti, and Paragonimus heterotremus.,Genomes ranged from 697 to 923 Mb, included 12,072-12,853 genes, and were 71.6-90.1% complete according to BUSCO.,Orthologous group analysis spanning 21 species (lung, liver, and blood flukes, additional platyhelminths, and hosts) provided insights into lung fluke biology.,We identified 256 lung fluke-specific and conserved orthologous groups with consistent transcriptional adult-stage Paragonimus expression profiles and enriched for iron acquisition, immune modulation, and other parasite functions.,Previously identified Paragonimus diagnostic antigens were matched to genes, providing an opportunity to optimize and ensure pan-Paragonimus reactivity for diagnostic assays.,This report provides advances in molecular understanding of Paragonimus and underpins future studies into the biology, evolution, and pathogenesis of Paragonimus and related foodborne flukes.,We anticipate that these novel genomic and transcriptomic resources will be invaluable for future lung fluke research.

Intermittent preventive treatment of malaria in pregnancy (IPTp) using sulphurdoxine-pyrimethamine (SP) is one of key malaria control strategies in Africa.,Yet, IPTp coverage rates across Africa are still low due to several demand and supply constraints.,Many countries implement the IPTp-SP strategy at antenatal care (ANC) clinics.,This paper reports from a study on the knowledge and experience of health workers (HWs) at ANC clinics regarding psychosocial, behavioural and health system barriers to IPTp-SP delivery and uptake in Tanzania.,Data were collected through questionnaire-based interviews with 78 HWs at 28 ANC clinics supplemented with informal discussions with current and recent ANC users in Mkuranga and Mufindi districts.,Qualitative data were analysed using a qualitative content analysis approach.,Quantitative data derived from interviews with HWs were analysed using non-parametric statistical analysis.,The majority of interviewed HWs were aware of the IPTp-SP strategy’s existence and of the recommended one month spacing of administration of SP doses.,Some HWs were unsure of that it is not recommended to administer IPTp-SP and ferrous/folic acid concurrently.,Others were administering three doses of SP per client following instruction from a non-governmental agency while believing that this was in conflict with national guidelines.,About half of HWs did not find it appropriate for the government to recommend private ANC providers to provide IPTp-SP free of charge since doing so forces private providers to recover the costs elsewhere.,HWs noted that pregnant women often register at clinics late and some do not comply with the regularity of appointments for revisits, hence miss IPTp and other ANC services.,HWs also noted some amplified rumours among clients regarding health risks and treatment failures of SP used during pregnancy, and together with clients’ disappointment with waiting times and the sharing of cups at ANC clinics for SP, limit the uptake of IPTp-doses.,HWs still question SP’s treatment advantages and are confused about policy ambiguity on the recommended number of IPTp-SP doses and other IPTp-SP related guidelines.,IPTp-SP uptake is further constrained by pregnant women’s perceived health risks of taking SP and of poor service quality.

While coverage of long-lasting insecticide-treated nets (LLIN) has steadily increased, a growing number of studies report gaps between net ownership and use.,We conducted a mixed-methods social science study assessing the importance of net preference and use after Olyset® LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.,The study was conducted in the catchment area of the Paujil and Cahuide Health Centres (San Juan district) between July 2007 and November 2008.,During a first qualitative phase, participant observation and in-depth interviews collected information on key determinants for net preference and use.,In a second quantitative phase, a survey among recently confirmed malaria patients evaluated the acceptability and use of both LLINs and traditional nets, and a case control study assessed the association between net preference/use and housing structure (open vs. closed houses).,A total of 10 communities were selected for the anthropological fieldwork and 228 households participated in the quantitative studies.,In the study area, bed nets are considered part of the housing structure and are therefore required to fulfil specific architectural and social functions, such as providing privacy and shelter, which the newly distributed Olyset® LLINs ultimately did not.,The LLINs' failure to meet these criteria could mainly be attributed to their large mesh size, transparency and perceived ineffectiveness to protect against mosquitoes and other insects, resulting in 63.3% of households not using any of the distributed LLINs.,Notably, LLIN usage was significantly lower in houses with no interior or exterior walls (35.2%) than in those with walls (73.8%) (OR = 5.2, 95CI [2.2; 12.3], p<0.001).,Net preference can interfere with optimal LLIN use.,In order to improve the number of effective days of LLIN protection per dollar spent, appropriate quantitative and qualitative methods for collecting information on net preference should be developed before any LLIN procurement decision is made.

Malaria remains a serious public health problem in Cameroon.,Implementation of control interventions requires prior knowledge of the local epidemiological situation.,Here we report the results of epidemiological and entomological surveys carried out in Tibati, Adamawa Region, Cameroon, an area where malaria transmission is seasonal, 6 years after the introduction of long-lasting insecticidal bed nets.,Cross-sectional studies were carried out in July 2015 and 2017 in Tibati.,Thick blood smears and dried blood spots were collected from asymptomatic and symptomatic individuals in the community and at health centers, respectively, and used for the molecular diagnosis of Plasmodium species.,Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly.,The infection status of Plasmodium spp. was determined by quantitative PCR, and positivity of PCR-positive samples was confirmed by Sanger sequencing.,Overall malaria prevalence in our study population was 55.0% (752/1367) and Plasmodium falciparum was the most prevalent parasite species (94.3%), followed by P. malariae (17.7%) and P. ovale (0.8%); 92 (12.7%) infections were mixed infections.,Infection parameters varied according to clinical status (symptomatic/asymptomatic) and age of the sampled population and the collection sites.,Infection prevalence was higher in asymptomatic carriers (60.8%), but asexual and sexual parasite densities were lower.,Prevalence and intensity of infection decreased with age in both the symptomatic and asymptomatic groups.,Heterogeneity in infections was observed at the neighborhood level, revealing hotspots of transmission.,Among the 592 Anopheles mosquitoes collected, 212 (35.8%) were An. gambiae, 172 (29.1%) were An. coluzzii and 208 (35.1%) were An. funestus (s.s.).,A total of 26 (4.39%) mosquito specimens were infected by Plasmodium sp. and the three Anopheles mosquitoes transmitted Plasmodium at equal efficiency.,Surprisingly, we found an An. coluzzii specimen infected by Plasmodium vivax, which confirms circulation of this species in Cameroon.,The positivity of all 26 PCR-positive Plasmodium-infected mosquitoes was successively confirmed by sequencing analysis.,Our study presents the baseline malaria parasite burden in Tibati, Adamawa Region, Cameroon.,Our results highlight the high malaria endemicity in the area, and hotspots of disease transmission are identified.,Parasitological indices suggest low bednet usage and that implementation of control interventions in the area is needed to reduce malaria burden.,We also report for the first time a mosquito vector with naturally acquired P. vivax infection in Cameroon.

As indigenous malaria has decreased over recent decades, the increasing number of imported malaria cases has provided a new challenge for China.,The proportion of imported cases due to Plasmodium ovale has increased during this time, and the difference between P. ovale curtisi and P. ovale wallikeri is of importance.,To better understand P. ovale epidemiology and the differences between the two subspecies, information on imported malaria in Henan Province was collected during 2010-2017.,We carried out a descriptive study to analyze the prevalence, proportion, distribution, and origin of P. o. curtisi and P. o. wallikeri.,It showed that imported P. ovale spp. accounts for a large proportion of total malaria cases in Henan Province, even more than that of P. vivax.,This suggests that the proportion of P. ovale cases is underestimated in Africa.,Among these cases, the latency period of P. o. curtisi was significantly longer than that of P. o. wallikeri.,More attention should be paid to imported ovale malaria to avoid the reintroduction of these two subspecies into China.

Background.,Current malaria diagnostic tests, including microscopy and antigen-detecting rapid tests, cannot reliably detect low-density infections.,Molecular methods such as polymerase chain reaction (PCR) are highly sensitive but remain too complex for field deployment.,A new commercial molecular assay based on loop-mediated isothermal amplification (LAMP) was assessed for field use.,Methods.,Malaria LAMP (Eiken Chemical, Japan) was evaluated for samples from 272 outpatients at a rural Ugandan clinic and compared with expert microscopy, nested PCR, and quantitative PCR (qPCR).,Two technicians performed the assay after 3 days of training, using 2 alternative blood sample-preparation methods and visual interpretation of results by fluorescence assay.,Results.,Compared with 3-well nested PCR, the sensitivity of both LAMP and single-well nested PCR was 90%; the microscopy sensitivity was 51%.,For samples with a Plasmodium falciparum qPCR titer of ≥2 parasites/µL, LAMP sensitivity was 97.8% (95% confidence interval, 93.7%-99.5%).,Most false-negative LAMP results involved samples with parasitemia levels detectable by 3-well nested PCR but very low or undetectable by qPCR.,Conclusions.,Malaria LAMP in a remote Ugandan clinic achieved sensitivity similar to that of single-well nested PCR in a United Kingdom reference laboratory.,LAMP dramatically lowers the detection threshold achievable in malaria-endemic settings, providing a new tool for diagnosis, surveillance, and screening in elimination strategies.

The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes.,While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 103 per mL.,We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay.,For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite).,The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature.,With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 103 parasites/mL.,Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL.,Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards.,This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.

Human to vector transmission of malaria requires that some blood stage parasites abandon asexual growth and convert into non-replicating sexual forms called gametocytes.,The initial steps of gametocytogenesis remain largely uncharacterized.,Here we studied this part of the malaria life cycle in Plasmodium falciparum using PfAP2-G, the master regulator of sexual conversion, as a marker of commitment.,We demonstrate the existence of PfAP2-G-positive sexually-committed parasite stages preceding the previously known committed schizont stage.,We also found that sexual conversion can occur by two different routes: the previously described route where PfAP2-G-expressing parasites complete a replicative cycle as committed forms before converting into gametocytes upon reinvasion, or a direct route with conversion within the same cycle as initial PfAP2-G expression.,The latter route is linked to early PfAP2-G expression in ring stages.,Re-analysis of published single-cell RNA-seq data confirmed the presence of both routes.,Consistent with these results, using plaque assays we observed that, in contrast to the prevailing model, many schizonts produced mixed plaques containing both asexual parasites and gametocytes.,Altogether, our results reveal unexpected features of the initial steps of sexual development and extend the current view of this part of the malaria life cycle.

Plasmodium falciparum immature gametocytes accumulate in the bone marrow, but their exact location in this tissue remains unclear.,The stage and deposition pattern of gametocytes was analysed on histological sections of a bone marrow sample collected in a patient with subacute P. falciparum malaria.,A majority (89%) of immature stages II to IV gametocytes and a minority (29%) of mature stage V gametocytes were observed in extravascular spaces.,These observations represent a valuable step towards understanding sequestration patterns of P. falciparum gametocytes and may ultimately lead to novel transmission-blocking interventions.

COVID-19 has the potential to cause substantial disruptions to health services, due to cases overburdening the health system or response measures limiting usual programmatic activities.,We aimed to quantify the extent to which disruptions to services for HIV, tuberculosis, and malaria in low-income and middle-income countries with high burdens of these diseases could lead to additional loss of life over the next 5 years.,Assuming a basic reproduction number of 3·0, we constructed four scenarios for possible responses to the COVID-19 pandemic: no action, mitigation for 6 months, suppression for 2 months, or suppression for 1 year.,We used established transmission models of HIV, tuberculosis, and malaria to estimate the additional impact on health that could be caused in selected settings, either due to COVID-19 interventions limiting activities, or due to the high demand on the health system due to the COVID-19 pandemic.,In high-burden settings, deaths due to HIV, tuberculosis, and malaria over 5 years could increase by up to 10%, 20%, and 36%, respectively, compared with if there was no COVID-19 pandemic.,The greatest impact on HIV was estimated to be from interruption to antiretroviral therapy, which could occur during a period of high health system demand.,For tuberculosis, the greatest impact would be from reductions in timely diagnosis and treatment of new cases, which could result from any prolonged period of COVID-19 suppression interventions.,The greatest impact on malaria burden could be as a result of interruption of planned net campaigns.,These disruptions could lead to a loss of life-years over 5 years that is of the same order of magnitude as the direct impact from COVID-19 in places with a high burden of malaria and large HIV and tuberculosis epidemics.,Maintaining the most critical prevention activities and health-care services for HIV, tuberculosis, and malaria could substantially reduce the overall impact of the COVID-19 pandemic.,Bill & Melinda Gates Foundation, Wellcome Trust, UK Department for International Development, and Medical Research Council.

The development and spread of artemisinin-resistant Plasmodium falciparum malaria in Greater Mekong Subregion has created impetus for continuing global monitoring of efficacy of artemisinin-based combination therapies (ACTs).,This post analyses is aimed to evaluate changes in early treatment response markers 10 years after the adoption of ACTs as first-line treatments of uncomplicated falciparum malaria in Nigeria.,At 14 sentinel sites in six geographical areas of Nigeria, we evaluated treatment responses in 1341 children under 5 years and in additional 360 children under 16 years with uncomplicated malaria enrolled in randomized trials of artemether-lumefantrine versus artesunate-amodiaquine at 5-year interval in 2009-2010 and 2014-2015 and at 2-year interval in 2009-2010 and 2012-2015, respectively after deployment in 2005.,Asexual parasite positivity 1 day after treatment initiation (APPD1) rose from 54 to 62% and 2 days after treatment initiation from 5 to 26% in 2009-2010 to 2014-2015 (P = 0.002 and P < 0.0001, respectively).,Parasite clearance time increased significantly from 1.6 days (95% confidence interval [CI]: 1.55-1.64) to 1.9 days (95% CI, 1.9-2.0) and geometric mean parasite reduction ratio 2 days after treatment initiation decreased significantly from 11 000 to 4700 within the same time period (P < 0.0001 for each).,Enrolment parasitaemia > 75 000 μl− 1, haematocrit > 27% 1 day post-treatment initiation, treatment with artemether-lumefantrine and enrolment in 2014-2015 independently predicted APPD1.,In parallel, Kaplan-Meier estimated risk of recurrent infections by day 28 rose from 8 to 14% (P = 0.005) and from 9 to 15% (P = 0.02) with artemether-lumefantrine and artesunate-amodiaquine, respectively.,Mean asexual parasitaemia half-life increased significantly from 1.1 h to 1.3 h within 2 years (P < 0.0001).,These data indicate declining parasitological responses through time to the two ACTs may be due to emergence of parasites with reduced susceptibility or decrease in immunity to the infections in these children.,Pan African Clinical Trial Registration PACTR201508001188143, 3 July 2015; PACTR201508001191898, 7 July 2015 and PACTR201508001193368, 8 July 2015 PACTR201510001189370, 3 July 2015; PACTR201709002064150, 1 March 2017; https://www.pactr.samrca.ac.za,The online version of this article (10.1186/s40249-019-0577-x) contains supplementary material, which is available to authorized users.

Trypanosoma cruzi infection via oral route results in outbreaks or cases of acute Chagas disease (ACD) in different Brazilian regions and poses a novel epidemiological scenario.,In the Espírito Santo state (southeastern Brazil), a fatal case of a patient with ACD led us to investigate the enzootic scenario to avoid the development of new cases.,At the studied locality, Triatoma vitticeps exhibited high T. cruzi infection rates and frequently invaded residences.,Sylvatic and domestic mammals in the Rio da Prata locality, where the ACD case occurred, and in four surrounding areas (Baia Nova, Buenos Aires, Santa Rita and Todos os Santos) were examined and underwent parasitological and serological tests.,Triatomines were collected for a fecal material exam, culturing and mini-exon gene molecular characterization, followed by RFLP-PCR of H3/Alul.,Paraffin-embedded cardiac tissue of a patient was washed with xylene to remove paraffin and DNA was extracted using the phenol-chloroform method.,For genotype characterization, PCR was performed to amplify the 1f8, GPI and 18S rRNA genes.,In the case of V7V8 SSU rRNA, the PCR products were molecularly cloned.,PCR products were sequenced and compared to sequences in GenBank.,Phylogenetic analysis using maximum likelihood method with 1000 bootstrap replicates was performed.,None of the animals showed positive hemocultures.,Three rodents and two dogs showed signs of infection, as inferred from borderline serological titers.,T. vitticeps was the only triatomine species identified and showed T. cruzi infection by DTUs TcI and TcIV.,The analysis of cardiac tissue DNA showed mixed infection by T. cruzi (DTUs I, II, III and IV) and Trypanosoma dionisii.,Each case or outbreak of ACD should be analyzed as a particular epidemiological occurrence.,The results indicated that mixed infections in humans may play a role in pathogenicity and may be more common than is currently recognized.,Direct molecular characterization from biological samples is essential because this procedure avoids parasite selection.,T. dionisii may under certain and unknown circumstances infect humans.,The distribution of T. cruzi DTUS TcIII and TcIV in Brazilian biomes is broader than has been assumed to date.,The online version of this article (doi:10.1186/s13071-016-1754-4) contains supplementary material, which is available to authorized users.

Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, is a major public health burden in Latin America and a potentially serious emerging threat to a number of countries throughout the world.,Although public health programs have significantly reduced the prevalence of Chagas disease in Latin America in recent decades, the number of infections in the United States and non-endemic countries in Europe and the Western Pacific Region continues to rise.,Moreover, there is still no vaccine or highly effective cure available for the approximately 10 million people currently infected with T. cruzi, a third of which will develop potentially fatal cardiomyopathy and/or severe digestive tract disorders.,As Chagas disease becomes an increasingly globalized public health issue in the twenty-first century, continued attentiveness from governmental and health organizations as well as improved diagnostic tools, expanded surveillance and increased research funding will be required to maintain existing public health successes and stymie the spread of the disease to new areas and populations.

Malaria is a major public health problem in Cameroon.,The study of the genetic diversity within parasite population is essential for understanding the mechanism underlying malaria pathology and to determine parasite clones profile in an infection, for proper malaria control strategies.,The objective of this study was to perform a molecular characterization of highly polymorphic genetic markers of Plasmodium falciparum, and to determine allelic distribution with their influencing factors valuable to investigate malaria transmission dynamics in Cameroon.,A total of 350 P. falciparum clinical isolates were characterized by genotyping block 2 of msp-1, block 3 of msp-2, and region II of glurp gene using nested PCR and DNA sequencing between 2012 and 2013.,A total of 5 different genotypes with fragment sizes ranging from 597 to 817 bp were recorded for GLURP.,Overall, 16 MSP-1 genotypes, including K1, MAD20 and RO33 were identified, ranging from 153 to 335 bp.,A peculiarity about this study is the RO33 monomorphic pattern revealed among the Pfmsp-1 allelic type.,Again, this study identified 27 different Pfmsp-2 genotypes, ranging from 140 to 568 bp in size, including 15 belonging to the 3D7-type and 12 to the FC27 allelic families.,The analysis of the MSP-1 and MSP-2 peptides indicates that the region of the alignment corresponding K1 polymorphism had the highest similarity in the MSP1and MSP2 clade followed by MAD20 with 93% to 100% homology.,Therefore, population structure of P. falciparum isolates is identical to that of other areas in Africa, suggesting that vaccine developed with K1 and MAD20 of Pfmsp1 allelic variant could be protective for Africa children but these findings requires further genetic and immunological investigations.,The multiplicity of infection (MOI) was significantly higher (P < 0.05) for Pfmsp-2 loci (3.82), as compare with Pfmsp-1 (2.51) and heterozygotes ranged from 0.55 for Pfmsp-1 to 0.96 for Pfmsp-2.,High genetic diversity and allelic frequencies in P. falciparum isolates indicate a persisting high level of transmission.,This study advocate for an intensification of the malaria control strategies in Cameroon.,Trial registration This study was approved by Cameroon National Ethics Committee.,It is a randomized controlled trial retrospectively registered in NIH U.S.,National Library of Medicine, ClinicalTrials.gov on the 28/11/2016 at https://clinicaltrials.gov/ct2/show/NCT02974348 with the registration number NCT02974348

An accurate diagnosis is essential for the rapid and appropriate treatment of malaria.,The accuracy of the histidine-rich protein 2 (PfHRP2)-based rapid diagnostic test (RDT) Palutop+4® was assessed here.,One possible factor contributing to the failure to detect malaria by this test is the diversity of the parasite PfHRP2 antigens.,PfHRP2 detection with the Palutop+4® RDT was carried out.,The pfhrp2 and pfhrp3 genes were amplified and sequenced from 136 isolates of Plasmodium falciparum that were collected in Dakar, Senegal from 2009 to 2011.,The DNA sequences were determined and statistical analyses of the variation observed between these two genes were conducted.,The potential impact of PfHRP2 and PfHRP3 sequence variation on malaria diagnosis was examined.,Seven P. falciparum isolates (5.9% of the total isolates, regardless of the parasitaemia; 10.7% of the isolates with parasitaemia ≤0.005% or ≤250 parasites/μl) were undetected by the PfHRP2 Palutop+4® RDT.,Low parasite density is not sufficient to explain the PfHRP2 detection failure.,Three of these seven samples showed pfhrp2 deletion (2.4%).,The pfhrp3 gene was deleted in 12.8%.,Of the 122 PfHRP2 sequences, 120 unique sequences were identified.,Of the 109 PfHRP3 sequences, 64 unique sequences were identified.,Using the Baker’s regression model, at least 7.4% of the P. falciparum isolates in Dakar were likely to be undetected by PfHRP2 at a parasite density of ≤250 parasites/μl (slightly lower than the evaluated prevalence of 10.7%).,This predictive prevalence increased significantly between 2009 and 2011 (P = 0.0046).,In the present work, 10.7% of the isolates with a parasitaemia ≤0.005% (≤250 parasites/μl) were undetected by the PfHRP2 Palutop+4® RDT (7.4% by the predictive Baker’model).,In addition, all of the parasites with pfhrp2 deletion (2.4% of the total samples) and 2.1% of the parasites with parasitaemia >0.005% and presence of pfhrp2 were not detected by PfHRP2 RDT.,PfHRP2 is highly polymorphic in Senegal.,Efforts should be made to more accurately determine the prevalence of non-sensitive parasites to pfHRP2.

Achieving a malaria-free world presents exciting scientific challenges as well as overwhelming health, equity, and economic benefits.,WHO and countries are setting ambitious goals for reducing the burden and eliminating malaria through the “Global Technical Strategy” and 21 countries are aiming to eliminate malaria by 2020.,The commitment to achieve these targets should be celebrated.,However, the need for innovation to achieve these goals, sustain elimination, and free the world of malaria is greater than ever.,Over 180 experts across multiple disciplines are engaged in the Malaria Eradication Research Agenda (malERA) Refresh process to address problems that need to be solved.,The result is a research and development agenda to accelerate malaria elimination and, in the longer term, transform the malaria community’s ability to eradicate it globally.,The malERA Refresh Consultative Panel on Health Systems and Policy Research summarize a research and development agenda to accelerate malaria elimination and eradicate globally.

Since the year 2000, a concerted campaign against malaria has led to unprecedented levels of intervention coverage across sub-Saharan Africa.,Understanding the effect of this control effort is vital to inform future control planning.,However, the effect of malaria interventions across the varied epidemiological settings of Africa remains poorly understood owing to the absence of reliable surveillance data and the simplistic approaches underlying current disease estimates.,Here we link a large database of malaria field surveys with detailed reconstructions of changing intervention coverage to directly evaluate trends from 2000 to 2015 and quantify the attributable effect of malaria disease control efforts.,We found that Plasmodium falciparum infection prevalence in endemic Africa halved and the incidence of clinical disease fell by 40% between 2000 and 2015.,We estimate that interventions have averted 663 (542-753 credible interval) million clinical cases since 2000.,Insecticide-treated nets, the most widespread intervention, were by far the largest contributor (68% of cases averted).,Although still below target levels, current malaria interventions have substantially reduced malaria disease incidence across the continent.,Increasing access to these interventions, and maintaining their effectiveness in the face of insecticide and drug resistance, should form a cornerstone of post-2015 control strategies.

Protozoan parasites of the genus Leishmania cause severe human and veterinary diseases worldwide, termed leishmaniases.,A hallmark of Leishmania biology is its capacity to adapt to a variety of unpredictable fluctuations inside its human host, notably pharmacological interventions, thus, causing drug resistance.,Here we investigated mechanisms of environmental adaptation using a comparative genomics approach by sequencing 10 new clinical isolates of the L. donovani, L. major, and L. tropica complexes that were sampled across eight distinct geographical regions.,Our data provide new evidence that parasites adapt to environmental change in the field and in culture through a combination of chromosome and gene amplification that likely causes phenotypic variation and drives parasite fitness gains in response to environmental constraints.,This novel form of gene expression regulation through genomic change compensates for the absence of classical transcriptional control in these early-branching eukaryotes and opens new venues for biomarker discovery.,Protozoan parasites of the genus Leishmania adapt to environmental change through chromosome and gene copy number variations.,Only little is known about external or intrinsic factors that govern Leishmania genomic adaptation.,Here, by conducting longitudinal genome analyses of 10 new Leishmania clinical isolates, we uncovered important differences in gene copy number among genetically highly related strains and revealed gain and loss of gene copies as potential drivers of long-term environmental adaptation in the field.,In contrast, chromosome rather than gene amplification was associated with short-term environmental adaptation to in vitro culture.,Karyotypic solutions were highly reproducible but unique for a given strain, suggesting that chromosome amplification is under positive selection and dependent on species- and strain-specific intrinsic factors.,We revealed a progressive increase in read depth towards the chromosome ends for various Leishmania isolates, which may represent a nonclassical mechanism of telomere maintenance that can preserve integrity of chromosome ends during selection for fast in vitro growth.,Together our data draw a complex picture of Leishmania genomic adaptation in the field and in culture, which is driven by a combination of intrinsic genetic factors that generate strain-specific phenotypic variations, which are under environmental selection and allow for fitness gain.

Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania.,New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia.,Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems.,Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes.,A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2).,This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology.

Efforts to control Schistosoma mansoni infection depend on the ability of programs to effectively detect and quantify infection levels and adjust programmatic approaches based on these levels and program goals.,One of the three major objectives of the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) has been to develop and/or evaluate tools that would assist Neglected Tropical Disease program managers in accomplishing this fundamental task.,The advent of a widely available point-of-care (POC) assay to detect schistosome circulating cathodic antigen (CCA) in urine with a rapid diagnostic test (the POC-CCA) in 2008 led SCORE and others to conduct multiple evaluations of this assay, comparing it with the Kato-Katz (KK) stool microscopy assay-the standard used for more than 45 years.,This article describes multiple SCORE-funded studies comparing the POC-CCA and KK assays, the pros and cons of these assays, the use of the POC-CCA assay for mapping of S. mansoni infections in areas across the spectrum of prevalence levels, and the validation and recognition that the POC-CCA, although not infallible, is a highly useful tool to detect low-intensity infections in low-to-moderate prevalence areas.,Such an assay is critical, as control programs succeed in driving down prevalence and intensity and seek to either maintain control or move to elimination of transmission of S. mansoni.

Moving from malaria control to elimination requires national malaria control programmes to implement strategies to detect both symptomatic and asymptomatic cases in the community.,In order to do this, malaria elimination programmes follow up malaria cases reported by health facilities to carry out case investigations that will determine the origin of the infection, whether it has been imported or is due to local malaria transmission.,If necessary, the malaria programme will also carry out active surveillance to find additional malaria cases in the locality to prevent further transmission.,To understand current practices and share information on malaria elimination strategies, a survey specifically addressing country policies on case investigation and reactive case detection was carried out among fourteen countries of the Asia Pacific Malaria Elimination Network (APMEN).,A questionnaire was distributed to the malaria control programme managers amongst 14 countries in the Asia Pacific who have national or sub-national malaria elimination goals.,Results indicate that there are a wide variety of case investigation and active case detection activities employed by the 13 countries that responded to the survey.,All respondents report conducting case investigation as part of surveillance activities.,More than half of these countries conduct investigations for each case.,Over half aim to accomplish the investigation within one to two days of a case report.,Programmes collect a broad array of demographic data during investigation procedures and definitions for imported cases are varied across respondents.,Some countries report intra-national (from a different province or district) importation while others report only international importation (from a different country).,Reactive case detection in respondent countries is defined as screening households within a pre-determined radius in order to identify other locally acquired infections, whether symptomatic or asymptomatic.,Respondents report that reactive case detection can be triggered in different ways, in some cases with only a single case report and in others if a defined threshold of multiple cases occurs.,The spatial range of screening conducted varies from a certain number of households to an entire administrative unit (e g, village).,Some countries target symptomatic people whereas others target all people in order to detect asymptomatic infections.,The majority of respondent programmes collect a range of information from those screened for malaria, similar to the range of information collected during case investigation.,Case investigation and reactive case detection are implemented in the malaria elimination programmes in the Asia Pacific, however practices vary widely from country to country.,There is little evidence available to support countries in deciding which methods to maintain, change or adopt for improved effectiveness and efficiency.,The development and use of common evaluation metrics for these activities will allow malaria programmes to assess performance and results of resource-intensive surveillance measures and may benefit other countries that are considering implementing these activities.

Cryptosporidium parvum is a zoonotic pathogen worldwide.,Extensive genetic diversity and complex population structures exist in C. parvum in different geographical regions and hosts.,Unlike the IIa subtype family, which is responsible for most zoonotic C. parvum infections in industrialized countries, IId is identified as the dominant subtype family in farm animals, rodents and humans in China.,Thus far, the population genetic characteristics of IId subtypes in calves in China are not clear.,In the present study, 46 C. parvum isolates from dairy and beef cattle in six provinces and regions in China were characterized using sequence analysis of eight genetic loci, including msc6-7, rpgr, msc6-5, dz-hrgp, chom3t, hsp70, mucin1 and gp60.,They belonged to three IId subtypes in the gp60 gene, including IIdA20G1 (n = 17), IIdA19G1 (n = 24) and IIdA15G1 (n = 5).,The data generated were analyzed for population genetic structures of C. parvum using DnaSP and LIAN and subpopulation structures using STRUCTURE, RAxML, Arlequin, GENALEX and Network.,Seventeen multilocus genotypes were identified.,The results of linkage disequilibrium analysis indicated the presence of an epidemic genetic structure in the C. parvum IId population.,When isolates of various geographical areas were treated as individual subpopulations, maximum likelihood inference of phylogeny, pairwise genetic distance analysis, substructure analysis, principal components analysis and network analysis all provided evidence for geographical segregation of subpopulations in Heilongjiang, Hebei and Xinjiang.,In contrast, isolates from Guangdong, Shanghai and Jiangsu were genetically similar to each other.,Data from the multilocus analysis have revealed a much higher genetic diversity of C. parvum than gp60 sequence analysis.,Despite an epidemic population structure, there is an apparent geographical segregation in C. parvum subpopulations within China.

•An outbreak of severe diarrhea was caused by Cryptosporidium parvum IIdA19G1 in dairy calves.,•Concurrence of rotavirus was present, but not as a significant cause of diarrhea in the investigation.,•Cryptosporidium parvum infection was associated with the occurrence of watery diarrhea in calves.,•Cryptosporidium ryanae and Cryptosporidium bovis infections were associated with the occurrence of moderate diarrhea.,An outbreak of severe diarrhea was caused by Cryptosporidium parvum IIdA19G1 in dairy calves.,Concurrence of rotavirus was present, but not as a significant cause of diarrhea in the investigation.,Cryptosporidium parvum infection was associated with the occurrence of watery diarrhea in calves.,Cryptosporidium ryanae and Cryptosporidium bovis infections were associated with the occurrence of moderate diarrhea.,Neonatal diarrhea is one of the most important syndromes in dairy cattle.,Among enteropathogens, Cryptosporidium spp. are primary causes of diarrhea, but outbreaks due to cryptosporidiosis are rarely reported in cattle.,From January to April in 2016, severe diarrhea was observed in over 400 neonatal dairy calves on a large dairy farm in Jiangsu Province of East China.,Approximately 360 calves died due to watery diarrhea despite antibiotic therapy.,In this study, 18 fecal specimens were collected from seriously ill calves on this farm during the diarrhea outbreak, and analysed for common enteropathogens by enzymatic immunoassay (EIA).,In a post-outbreak investigation, 418 and 1372 specimens collected from animals of various age groups were further analysed for rotavirus and Cryptosporidium spp. by EIA and PCR, respectively, to assess their roles in the occurrence of diarrhea on the farm.,Cryptosporidium spp. were genotyped using established techniques.,Initial EIA tests showed that 15/18 seriously ill calves during the outbreak were positive for Cryptosporidium parvum, while 8/18 were positive for rotavirus.,The overall infection rate of Cryptosporidium in pre-weaned calves on the farm was 22.7%, with odds of the Cryptosporidium infection during the outbreak 4.4-23.5 times higher than after the outbreak.,Four Cryptosporidium spp. were identified after the outbreak including C. parvum (n = 79), Cryptosporidium ryanae (n = 48), Cryptosporidium bovis (n = 31), and Cryptosporidium andersoni (n = 3), with co-infections of multiple species being detected in 34 animals.,Infection with C. parvum (73/79) was found in the majority of calves aged ≤3 weeks, consistent with the age of ill calves during the outbreak.,All C. parvum isolates were identified as subtype IIdA19G1.,In the post-outbreak investigation, C. parvum infection was associated with the occurrence of watery diarrhea in pre-weaned calves, C. ryanae infection was associated with moderate diarrhea in both pre- and post-weaned calves, while no association was identified between rotavirus infection and the occurrence of diarrhea.,Results of logistic regression analysis further suggested that C. bovis infection might also be a risk factor for moderate diarrhea in calves.,Thus, we believe this is the first report of a major outbreak of severe diarrhea caused by C. parvum IIdA19G1 in dairy calves.,More attention should be directed toward preventing the dissemination of this virulent subtype in China.

Malaria is a disease with diverse symptoms depending on host immune status and pathogenicity of Plasmodium parasites.,The continuous parasite growth within a host suggests mechanisms of immune evasion by the parasite and/or immune inhibition in response to infection.,To identify pathways commonly inhibited after malaria infection, we infected C57BL/6 mice with four Plasmodium yoelii strains causing different disease phenotypes and 24 progeny of a genetic cross. mRNAs from mouse spleens day 1 and/or day 4 post infection (p.i.) were hybridized to a mouse microarray to identify activated or inhibited pathways, upstream regulators, and host genes playing an important role in malaria infection.,Strong interferon responses were observed after infection with the N67 strain, whereas initial inhibition and later activation of hematopoietic pathways were found after infection with 17XNL parasite, showing unique responses to individual parasite strains.,Inhibitions of pathways such as Th1 activation, dendritic cell (DC) maturation, and NFAT immune regulation were observed in mice infected with all the parasite strains day 4 p.i., suggesting universally inhibited immune pathways.,As a proof of principle, treatment of N67-infected mice with antibodies against T cell receptors OX40 or CD28 to activate the inhibited pathways enhanced host survival.,Controlled activation of these pathways may provide important strategies for better disease management and for developing an effective vaccine.

Antibodies (Abs) are critical for immunity to malaria.,However, Plasmodium falciparum specific Abs decline rapidly in absence of reinfection, suggesting impaired immunological memory.,This study determines whether residents of Sweden that were treated for malaria following international travel maintained long‐lasting malaria‐specific Abs and memory B cells (MBCs).,We compared levels of malaria‐specific Abs and MBCs between 47 travelers who had been admitted with malaria at the Karolinska University Hospital between 1 and 16 years previously, eight malaria‐naïve adult Swedes without histories of travel, and 14 malaria‐immune adult Kenyans.,Plasmodium falciparum‐lysate‐specific Ab levels were above naïve control levels in 30% of the travelers, whereas AMA‐1, merozoite surface protein‐142, and merozoite surface protein‐3‐specific Ab levels were similar.,In contrast, 78% of travelers had IgG‐MBCs specific for at least one malaria antigen (59, 45, and 28% for apical merozoite antigen‐1, merozoite surface protein‐1, and merozoite surface protein‐3, respectively) suggesting that malaria‐specific MBCs are maintained for longer than the cognate serum Abs in the absence of re‐exposure to parasites.,Five travelers maintained malaria antigen‐specific MBC responses for up to 16 years since the diagnosis of the index episode (and had not traveled to malaria‐endemic regions in the intervening time).,Thus P. falciparum can induce long‐lasting MBCs, maintained for up to 16 years without reexposure.

In endemic regions, the age distribution of malaria varies according to the infecting Plasmodium species.,We aimed to delineate the pattern of malaria-related hospitalization from birth in Timika, Papua-an area co-endemic for P. falciparum and P. vivax,Between April 2004 and December 2013, infants born at Mitra Masyarakat Hospital, or presenting within the first 7 days of life, were enrolled retrospectively into a cohort study and followed passively using routinely-collected hospital surveillance data.,Outcomes were stratified by the presence or absence of Plasmodium parasitemia and included re-presentation to hospital, requirement for hospital admission and death.,Overall, 11,408 infants were enrolled into the cohort.,Median follow-up was 4.3 (maximum 9.7) years.,In total, 7,847 (68.9%) infants made 90,766 re-presentations to hospital, 18,105 (19.9%) of which were associated with Plasmodium parasitemia.,The incidence of re-presentations with malaria during the first year of life was 213 per 1,000 person-years (py) for P. vivax and 79 per 1,000py for P. falciparum (Incidence Rate Ratio (IRR) = 2.69, 95% Confidence Interval (95%CI): 2.48-2.92).,After the age of 5 years, the incidence of P. vivax had fallen to 77/1,000py and the incidence of P. falciparum had risen to 95/1,000py (IRR = 0.80, 95%CI: 0.73-0.88).,Overall, 79.7% (14,431/18,105) of malaria re-presentations were recurrences rather than initial infections.,Malaria accounted for 31.7% (2,126/3,120) of all hospital admissions.,The infant mortality rate in this study was 52 deaths per 1,000 live births.,Beyond the early neonatal period, 13.4% of deaths were associated with Plasmodium parasitemia.,In Papua, Indonesia, malaria is a major cause of hospital presentation and admission in early life.,The initial predominance of P. vivax over P. falciparum inverts after five years of age.,Malaria is directly associated with nearly one in seven deaths after the early neonatal period.

Ric Price and colleagues use hospital-based surveillance data to estimate the risk of severe anemia and mortality associated with endemic Plasmodium species in southern Papua, Indonesia.,Please see later in the article for the Editors' Summary,The burden of anemia attributable to non-falciparum malarias in regions with Plasmodium co-endemicity is poorly documented.,We compared the hematological profile of patients with and without malaria in southern Papua, Indonesia.,Clinical and laboratory data were linked for all patients presenting to a referral hospital between April 2004 and December 2012.,Data were available on patient demographics, malaria diagnosis, hemoglobin concentration, and clinical outcome, but other potential causes of anemia could not be identified reliably.,Of 922,120 patient episodes (837,989 as outpatients and 84,131 as inpatients), a total of 219,845 (23.8%) were associated with a hemoglobin measurement, of whom 67,696 (30.8%) had malaria.,Patients with P. malariae infection had the lowest hemoglobin concentration (n = 1,608, mean = 8.93 [95% CI 8.81-9.06]), followed by those with mixed species infections (n = 8,645, mean = 9.22 [95% CI 9.16-9.28]), P. falciparum (n = 37,554, mean = 9.47 [95% CI 9.44-9.50]), and P. vivax (n = 19,858, mean = 9.53 [95% CI 9.49-9.57]); p-value for all comparisons <0.001.,Severe anemia (hemoglobin <5 g/dl) was present in 8,151 (3.7%) patients.,Compared to patients without malaria, those with mixed Plasmodium infection were at greatest risk of severe anemia (adjusted odds ratio [AOR] 3.25 [95% CI 2.99-3.54]); AORs for severe anaemia associated with P. falciparum, P. vivax, and P. malariae were 2.11 (95% CI 2.00-2.23), 1.87 (95% CI 1.74-2.01), and 2.18 (95% CI 1.76-2.67), respectively, p<0.001.,Overall, 12.2% (95% CI 11.2%-13.3%) of severe anemia was attributable to non-falciparum infections compared with 15.1% (95% CI 13.9%-16.3%) for P. falciparum monoinfections.,Patients with severe anemia had an increased risk of death (AOR = 5.80 [95% CI 5.17-6.50]; p<0.001).,Not all patients had a hemoglobin measurement, thus limitations of the study include the potential for selection bias, and possible residual confounding in multivariable analyses.,In Papua P. vivax is the dominant cause of severe anemia in early infancy, mixed P. vivax/P. falciparum infections are associated with a greater hematological impairment than either species alone, and in adulthood P. malariae, although rare, is associated with the lowest hemoglobin concentration.,These findings highlight the public health importance of integrated genus-wide malaria control strategies in areas of Plasmodium co-endemicity.,Please see later in the article for the Editors' Summary,Malaria-a mosquito-borne parasitic disease-is a global public health problem.,Five parasites cause malaria-Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi.,Of these, P. vivax is the commonest and most widely distributed, whereas P. falciparum causes the most deaths-about a million every year.,All these parasites enter their human host when an infected mosquito takes a blood meal.,The parasites migrate to the liver where they replicate and mature into a parasitic form known as merozoites.,After 8-9 days, the merozoites are released from the liver cells and invade red blood cells where they replicate rapidly before bursting out and infecting more red blood cells.,Malaria's recurring flu-like symptoms are caused by this cyclical increase in parasites in the blood.,Malaria needs to be treated promptly with antimalarial drugs to prevent the development of potentially fatal complications.,Infections with P. falciparum in particular can cause anemia (a reduction in red blood cell numbers) and can damage the brain and other vital organs by blocking the capillaries that supply these organs with blood.,It is unclear what proportion of anemia is attributable to non-falciparum malarias in regions of the world where several species of malaria parasite are always present (Plasmodium co-endemicity).,Public health officials in such regions need to know whether non-falciparum malarias are a major cause of anemia when designing malaria control strategies.,If P. vivax, for example, is a major cause of anemia in an area where P. vivax and P. falciparum co-exist, then any malaria control strategies that are implemented need to take into account the biological differences between the parasites.,In this hospital-based cohort study, the researchers investigate the burden of severe anemia from the endemic Plasmodium species in southern Papua, Indonesia.,The researchers used hospital record numbers to link clinical and laboratory data for patients presenting to a referral hospital in southern Papua over an 8-year period.,The hemoglobin level (an indicator of anemia) was measured in about a quarter of hospital presentations (some patients attended the hospital several times).,A third of the presentations who had their hemoglobin level determined (67,696 presentations) had clinical malaria.,Patients with P. malariae infection had the lowest average hemoglobin concentration.,Patients with mixed species, P. falciparum, and P. vivax infections had slightly higher average hemoglobin levels but all these levels were below the normal range for people living in Papua.,Among the patients who had their hemoglobin status assessed, 3.7% had severe anemia.,After allowing for other factors that alter the risk of anemia (“confounding” factors such as age), patients with mixed Plasmodium infection were more than three times as likely to have severe anemia as patients without malaria.,Patients with P. falciparum, P. vivax, or P. malariae infections were about twice as likely to have severe anemia as patients without malaria.,About 12.2% of severe anemia was attributable to non-falciparum infections, 15.1% was attributable to P. falciparum monoinfections, and P. vivax was the dominant cause of severe anemia in infancy.,Finally, compared to patients without anemia, patients with severe anemia had nearly a 6-fold higher risk of death.,These findings provide a comparative assessment of the pattern of anemia associated with non-falciparum malarias in Papua and an estimate of the public health importance of these malarias.,Although the accuracy of these findings may be affected by residual confounding (for example, the researchers did not consider nutritional status when calculating how much malaria infection increases the risk of anemia) and other limitations of the study design, non-falciparum malarias clearly make a major contribution to the burden of anemia in southern Papua.,In particular, these findings reveal the large contribution that P. vivax makes to severe anemia in infancy, show that the hematological (blood-related) impact of P. malariae is most apparent in adulthood, and suggest, in contrast to some previous reports, that mixed P. vivax/P. falciparum infection is associated with a higher risk of severe anemia than monoinfection with either species.,These findings, which need to be confirmed in other settings, highlight the public health importance of implementing integrated malaria control strategies that aim to control all Plasmodium species rather than a single species in regions of Plasmodium co-endemicity.,Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001575.,This study is further discussed in a PLOS Medicine Perspective by Gosling and Hsiang,Information is available from the World Health Organization on malaria (in several languages); the 2012 World Malaria Report provides details of the current global malaria situation,The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish), including information on different Plasmodium species and a selection of personal stories about malaria,The Malaria Vaccine Initiative has fact sheets on Plasmodium falciparum malaria and on Plasmodium vivax malaria,MedlinePlus provides links to additional information on malaria and on anemia (in English and Spanish),Information is available from the WorldWide Antimalarial Resistance Network on antimalarial drug resistance for P. falciparum and P. vivax

Historically, the target in the schistosomiasis control has shifted from infection to morbidity, then back to infection, but now as a public health problem, before moving on to transmission control.,Currently, all endemic countries are encouraged to increase control efforts and move towards elimination as required by the World Health Organization (WHO) roadmap for the global control of the neglected tropical diseases (NTDs) and the WHA65.21 resolution issued by the World Health Assembly.,However, schistosomiasis prevalence is still alarmingly high and the global number of disability-adjusted life years (DALYs) due to this infection has in fact increased due to inclusion of some ‘subtle’ clinical symptoms not previously counted.,There is a need to restart and improve efforts to reach the elimination goal.,To that end, the first conference of the Global Schistosomiasis Alliance (GSA) Research Working Group was held in mid-June 2016 in Shanghai, People’s Republic of China.,It reviewed current progress in schistosomiasis control and elimination, identified pressing operational research gaps that need to be addressed and discussed new tools and strategies required to make elimination a reality.,The articles emanating from the lectures and discussions during this meeting, together with some additional invited papers, have been collected as a special issue of the ‘Infectious Diseases of Poverty’ entitled ‘Schistosomiasis Research: Providing the Tools Needed for Elimination’, consisting of 26 papers in all.,This paper refers to these papers and discusses critical questions arising at the conference related to elimination of schistosomiasis.,The currently most burning questions are the following: Can schistosomiasis be eliminated?,Does it require better, more highly sensitive diagnostics?,What is the role of preventive chemotherapy at the elimination stage?,Is praziquantel sufficient or do we need new drugs?,Contemplating these questions, it is felt that the heterogeneity of the endemic areas in the world requires WHO policies to be upgraded instituting new, differentiated guidelines.,The online version of this article (doi: 10.1186/s40249-017-0370-7) contains supplementary material, which is available to authorized users.

Schistosomiasis is a disease caused by infection with blood flukes of the genus Schistosoma.,Transmission of, and exposure to, the parasite result from faecal or urinary contamination of freshwater containing intermediate host snails, and dermal contact with the same water.,The World Health Assembly resolution 65.21 from May 2012 urges member states to eliminate schistosomiasis through preventive chemotherapy (i.e. periodic large-scale administration of the antischistosomal drug praziquantel to school-aged children and other high-risk groups), provision of water, sanitation and hygiene (WASH) and snail control.,However, control measures focus almost exclusively on preventive chemotherapy, while only few studies made an attempt to determine the impact of upgraded access to safe water, adequate sanitation and good hygiene on schistosome transmission.,We recently completed a systematic review and meta-analysis pertaining to WASH and schistosomiasis and found that people with safe water and adequate sanitation have significantly lower odds of a Schistosoma infection.,Importantly though, the transmission of schistosomiasis is deeply entrenched in social-ecological systems, and hence is governed by setting-specific cultural and environmental factors that determine human behaviour and snail populations.,Here, we provide a comprehensive review of the literature, which explores the transmission routes of schistosomes, particularly focussing on how these might be disrupted with WASH-related technologies and human behaviour.,Additionally, future research directions in this area are highlighted.

The dire lack of information concerning the epidemiology of human scabies in Cameroon, especially in school milieus brought us to undertake the present study which aimed to determine the prevalence and associated factors of scabies in Cameroonian boarding schools.,A cross-sectional study was conducted from February to March 2015 in four boarding schools in Yaoundé and Buea (Cameroon).,Participants were students currently residing in one of the study sites, volunteering to participate in the study and whose parents or guardians had given their consent in this respect.,The diagnosis was based on clinical assessment independently performed by two dermatologists.,A total of 1,902 students were recruited (50.5 % boys), with a mean age of 14.3 ± 2.5 years.,Overall, 338 participants (17.8 %) were diagnosed with scabies.,Age ≤ 15 years, male sex, number of students in the school > 500, no access to the school infirmary, sleeping with others, sharing beddings, clothes or toilet stuffs, pruritus in the close entourage and complaining of pruritus were significantly associated with the presence of mites in univariable logistic regression analyses.,On the other hand, at least two baths per day, usage of soap for baths and finger nails always cut short appeared as protective factors.,After multivariable analysis, male sex (adjusted OR (aOR) 2.06, 95 % CI: 1.40-3.01, P < 0.0001), first cycle level of education (aOR 1.67, 95 % CI: 1.02-2.71, P = 0.040), number of students per dormitory ≤ 10 (aOR 6.99, 95 % CI: 3.34-14.71, P < 0.0001), no access to the school infirmary (aOR 1.62, 95 % CI: 1.12-2.32, P = 0.009) and complaining of pruritus (aOR 93.37, 95 % CI: 60.04-145.19, P < 0.0001) were the independent factors associated with scabies.,The prevalence of scabies was 17.8 %.,The male sex, first cycle level of education, a number of students per dormitory ≤ 10, no access to the school infirmary and complaining of pruritus were the independent factors significantly impacting the occurrence of scabies.

Various dermatoses, due to their morbidity characteristics, have been shown to negatively impact on learning.,The most epidemiologically important seem to be the infectious types because of their transmissibility and amenability to simple school-health measures.,The aim of this study was to assess the prevalence and sex/age correlates of infectious dermatoses in a rural South-eastern Nigerian community.,The pupils were proportionately recruited from the three primary schools based on school population.,Stratified simple random sampling method was adopted and a table of random numbers was used to select required pupils from each arm.,Clinical and laboratory examination was done to establish diagnoses of infectious skin disease.,Data collected were analyzed using SPSS version 16.,The 400 pupils consisted of 153 males and 247 females.,Age range was between 6 and 12 years.,The prevalence of infectious dermatoses was 72.3%.,The five most prevalent clinical forms of infectious dermatoses, in order of decreasing prevalence, were tinea capitis (35.2%), scabies (10.5%), tinea corporis (5.8%), tinea pedis (5.5%), and impetigo (5.0%).,More cases, generally, occurred among males than females (80.4% vs 67.2%)); while some specific clinical types, pediculosis and seborrheic dermatitis, exhibited predilection for females.,Pyodermas and scabies were significantly more prevalent in the 7-9 age-group; while tinea capitis, tinea corporis, seborrheic dermatitis and pediculosis were more associated with ≥10 age-group.,Infectious dermatoses were highly prevalent in the surveyed population.,Many of the clinical types exhibited sex- and age-specificity.

Understanding how immunity to malaria is affected by declining transmission is important to aid vaccine design and understand disease resurgence.,Both IgG subclasses and avidity of antigen-specific responses are important components of an effective immune response.,Using a multiplex bead array assay, we measured the total IgG, IgG subclasses, and avidity profiles of responses to 18 P. falciparum blood stage antigens in samples from 160 Ugandans collected at two time points during high malaria transmission and two time points following a dramatic reduction in transmission.,Results demonstrated that, for the antigens tested, (i) the rate of decay of total IgG following infection declined with age and was driven consistently by the decrease in IgG3 and occasionally the decrease in IgG1; (ii) the proportion of IgG3 relative to IgG1 in the absence of infection increased with age; (iii) the increase in avidity index (the strength of association between the antibody and antigen) following infection was largely due to a rapid loss of non-avid compared to avid total IgG; and (iv) both avid and non-avid total IgG in the absence of infection increased with age.,Further studies are required to understand the functional differences between IgG1 and IgG3 in order to determine their contribution to the longevity of protective immunity to malaria.,Measuring changes in antibody avidity may be a better approach of detecting affinity maturation compared to avidity index due to the differential expansion and contraction of high and low avidity total IgG.

The study of antigenic targets of naturally-acquired immunity is essential to identify and prioritize antigens for further functional characterization.,We measured total IgG antibodies to 38 P. vivax antigens, investigating their relationship with prospective risk of malaria in a cohort of 1-3 years old Papua New Guinean children.,Using simulated annealing algorithms, the potential protective efficacy of antibodies to multiple antigen-combinations, and the antibody thresholds associated with protection were investigated for the first time.,High antibody levels to multiple known and newly identified proteins were strongly associated with protection (IRR 0.44-0.74, p<0.001-0.041).,Among five-antigen combinations with the strongest protective effect (>90%), EBP, DBPII, RBP1a, CyRPA, and PVX_081550 were most frequently identified; several of them requiring very low antibody levels to show a protective association.,These data identify individual antigens that should be prioritized for further functional testing and establish a clear path to testing a multicomponent P. vivax vaccine.

In this study, we have utilized wild-type (WT), ASC−/−, and NLRP3−/− macrophages and inhibition approaches to investigate the mechanisms of inflammasome activation and their role in Trypanosoma cruzi infection.,We also probed human macrophages and analyzed published microarray datasets from human fibroblasts, and endothelial and smooth muscle cells for T. cruzi-induced changes in the expression genes included in the RT Profiler Human Inflammasome arrays.,T. cruzi infection elicited a subdued and delayed activation of inflammasome-related gene expression and IL-1β production in mφs in comparison to LPS-treated controls.,When WT and ASC−/− macrophages were treated with inhibitors of caspase-1, IL-1β, or NADPH oxidase, we found that IL-1β production by caspase-1/ASC inflammasome required reactive oxygen species (ROS) as a secondary signal.,Moreover, IL-1β regulated NF-κB signaling of inflammatory cytokine gene expression and, subsequently, intracellular parasite replication in macrophages.,NLRP3−/− macrophages, despite an inability to elicit IL-1β activation and inflammatory cytokine gene expression, exhibited a 4-fold decline in intracellular parasites in comparison to that noted in matched WT controls.,NLRP3−/− macrophages were not refractory to T. cruzi, and instead exhibited a very high basal level of ROS (>100-fold higher than WT controls) that was maintained after infection in an IL-1β-independent manner and contributed to efficient parasite killing.,We conclude that caspase-1/ASC inflammasomes play a significant role in the activation of IL-1β/ROS and NF-κB signaling of cytokine gene expression for T. cruzi control in human and mouse macrophages.,However, NLRP3-mediated IL-1β/NFκB activation is dispensable and compensated for by ROS-mediated control of T. cruzi replication and survival in macrophages.

We utilized genetically modified mice equipped with a variable capacity to scavenge mitochondrial and cellular reactive oxygen species to investigate the pathological significance of oxidative stress in Chagas disease.,C57BL/6 mice (wild type, MnSODtg, MnSOD+/−, GPx1−/−) were infected with Trypanosoma cruzi and harvested during the chronic disease phase.,Chronically infected mice exhibited a substantial increase in plasma levels of inflammatory markers (nitric oxide, myeloperoxidase), lactate dehydrogenase, and myocardial levels of inflammatory infiltrate and oxidative adducts (malondialdehyde, carbonyls, 3‐nitrotyrosine) in the order of wild type=MnSOD+/−>GPx1−/−>MnSODtg.,Myocardial mitochondrial damage was pronounced and associated with a >50% decline in mitochondrial DNA content in chronically infected wild‐type and GPx1−/− mice.,Imaging of intact heart for cardiomyocytes and collagen by the nonlinear optical microscopy techniques of multiphoton fluorescence/second harmonic generation showed a significant increase in collagen (>10‐fold) in chronically infected wild‐type mice, whereas GPx1−/− mice exhibited a basal increase in collagen that did not change during the chronic phase.,Chronically infected MnSODtg mice exhibited a marginal decline in mitochondrial DNA content and no changes in collagen signal in the myocardium.,P47phox−/− mice lacking phagocyte‐generated reactive oxygen species sustained a low level of myocardial oxidative stress and mitochondrial DNA damage in response to Trypanosoma cruzi infection.,Yet chronically infected p47phox−/− mice exhibited increase in myocardial inflammatory and remodeling responses, similar to that noted in chronically infected wild‐type mice.,Inhibition of oxidative burst of phagocytes was not sufficient to prevent pathological cardiac remodeling in Chagas disease.,Instead, enhancing the mitochondrial reactive oxygen species scavenging capacity was beneficial in controlling the inflammatory and oxidative pathology and the cardiac remodeling responses that are hallmarks of chronic Chagas disease.

In Tanzania there has been a downward trend in malaria prevalence partly due to use of insecticide-treated bed nets for protection against Anopheles mosquitoes.,However, residual malaria transmission attributed to early biting behaviour of malaria vectors is being reported.,Knowledge of mosquito feeding behaviour is key to improvements in control approaches.,The present study aimed to assess knowledge and awareness on malaria and malaria vectors in-Morogoro and Dodoma regions of Tanzania.,A cross sectional study was undertaken in selected sites in Morogoro and Dodoma Tanzania.,A structured questionnaire was administered to 218 randomly selected households from each of which the head or second in/charge and the most senior primary school child were interviewed.,A total of 400 participants of whom 56 % were females, were recruited into the study.,Their ages ranged between nine and 58 years.,Among the participants, 70.7 % had primary school education and the rest attained secondary school (16.8 %), university/college (4.0 %) and not attended school at all (8.5 %).,Fifteen per cent of the participants were employed, while 45.5 % were self-employed and 39.5 % were studying.,Overall, 58.5 % of respondents were knowledgeable of malaria and its vector.,However, 78.8 % were not aware that early mosquito bites can transmit malaria and 86.5 % said that only midnight-biting mosquito bite was responsible for malaria transmission.,The majority (66 %) of respondents visited a health facility on observing malaria symptoms while 15.8 % took anti-malaria drugs without medical consultation.,This study has shown that Anopheles is well known as the night-biting vector of malaria.,The majority of participants were not aware of changed biting behaviour of malaria-transmitting mosquitoes and that early outdoor mosquito bite is a risk of malaria transmission.,School children have shown a better understanding of malaria and its vector.,Therefore, more awareness of Anopheles feeding behaviour is needed.,The online version of this article (doi:10.1186/s12936-016-1332-4) contains supplementary material, which is available to authorized users.

This paper responds to a recent call for malaria to be re-imagined by: explaining why it needs to be re-imagined; offering one possible way in which this can be done; and describing some of benefits for malaria control when it is.,This study involved conducting a 15-week photovoice project with 44 predominantly ethnically Palawan school-going children in the municipality of Bataraza in the Philippines.,The primary aim was to critically examine how facilitating children to take their own pictures of malaria could alter their understanding of it as well as the practices that they then engaged into prevent and treat it.,During the photovoice process, participants responded to the question, ‘what does malaria mean to you?’,by photographing multiple versions of malaria.,Some of these versions align with biomedical conceptions and mirror common images of: its sources (e.g. mosquitoes); symptoms (e.g. fever); prevention practices (e.g. use of mosquito nets); diagnostic practices (e.g. use Rapid Diagnostic Tests) and treatment practices (e.g. use of anti-malarial drugs).,However, in addition to these depictions, participants also took images of malaria that aligned with more local understanding of the body, health and well-being, which are often neglected by health practitioners.,In the case of the Palawan, these versions of malaria are structured around the central tenet of balance.,Participants therefore photographed themselves and members of their family and community engaging in a number of practices, which are orientated towards restoring and maintaining balance.,As well being an effective means to illuminate multiple malarias and the practices that surround them, photovoice also enabled participants to learn new things and significantly, teach these things to others using their images.,Photovoice is an effective method for re-imaging malaria.,It allowed participants to depict and describe multiple versions of malaria and the practices that they engage in in context.,Photovoice also had a potentially transformative effect.,It acted as a means for participants and researchers to: visually depict everyday practices; collectively gain a deeper understanding of this doing; and then seek ways in which to make changes in line with this joint understanding.

The study of antigenic targets of naturally-acquired immunity is essential to identify and prioritize antigens for further functional characterization.,We measured total IgG antibodies to 38 P. vivax antigens, investigating their relationship with prospective risk of malaria in a cohort of 1-3 years old Papua New Guinean children.,Using simulated annealing algorithms, the potential protective efficacy of antibodies to multiple antigen-combinations, and the antibody thresholds associated with protection were investigated for the first time.,High antibody levels to multiple known and newly identified proteins were strongly associated with protection (IRR 0.44-0.74, p<0.001-0.041).,Among five-antigen combinations with the strongest protective effect (>90%), EBP, DBPII, RBP1a, CyRPA, and PVX_081550 were most frequently identified; several of them requiring very low antibody levels to show a protective association.,These data identify individual antigens that should be prioritized for further functional testing and establish a clear path to testing a multicomponent P. vivax vaccine.

Plasmodium vivax is a major cause of febrile illness in endemic areas of Asia, Central and South America, and the horn of Africa.,Plasmodium vivax infections are characterized by relapses of malaria arising from persistent liver stages of the parasite (hypnozoites) which can be prevented only by 8-aminoquinoline anti-malarials.,Tropical P. vivax relapses at three week intervals if rapidly eliminated anti-malarials are given for treatment, whereas in temperate regions and parts of the sub-tropics P. vivax infections are characterized either by a long incubation or a long-latency period between illness and relapse - in both cases approximating 8-10 months.,The epidemiology of the different relapse phenotypes has not been defined adequately despite obvious relevance to malaria control and elimination.,The number of sporozoites inoculated by the anopheline mosquito is an important determinant of both the timing and the number of relapses.,The intervals between relapses display a remarkable periodicity which has not been explained.,Evidence is presented that the proportion of patients who have successive relapses is relatively constant and that the factor which activates hypnozoites and leads to regular interval relapse in vivax malaria is the systemic febrile illness itself.,It is proposed that in endemic areas a large proportion of the population harbours latent hypnozoites which can be activated by a systemic illness such as vivax or falciparum malaria.,This explains the high rates of vivax following falciparum malaria, the high proportion of heterologous genotypes in relapses, the higher rates of relapse in people living in endemic areas compared with artificial infection studies, and, by facilitating recombination between different genotypes, contributes to P. vivax genetic diversity particularly in low transmission settings.,Long-latency P. vivax phenotypes may be more widespread and more prevalent than currently thought.,These observations have important implications for the assessment of radical treatment efficacy and for malaria control and elimination.

Programmatic surveillance of intestinal schistosomiasis during control can typically use four diagnostic tests, either singularly or in combination, but these have yet to be cross-compared directly.,Our study assembled a complete diagnostic dataset, inclusive of infection intensities, from 258 children from five Ugandan primary schools.,The schools were purposely selected as typical of the endemic landscape near Lake Albert and reflective of high- and low-transmission settings.,Overall prevalence was: 44.1% (95% CI 38.0-50.2) by microscopy of duplicate Kato-Katz smears from two consecutive stools, 56.9% (95% CI 50.8-63.0) by urine-circulating cathodic antigen (CCA) dipstick, 67.4% (95% CI 61.6-73.1) by DNA-TaqMan® and 75.1% (95% CI 69.8-80.4) by soluble egg antigen enzyme-linked immunosorbent assay (SEA-ELISA).,A cross-comparison of diagnostic sensitivities, specificities, positive and negative predictive values was undertaken, inclusive of a latent class analysis (LCA) with a LCA-model estimate of prevalence by each school.,The latter ranged from 9.6% to 100.0%, and prevalence by school for each diagnostic test followed a static ascending order or monotonic series of Kato-Katz, urine-CCA dipstick, DNA-TaqMan® and SEA-ELISA.,We confirm that Kato-Katz remains a satisfactory diagnostic standalone in high-transmission settings but in low-transmission settings should be augmented or replaced by urine-CCA dipsticks.,DNA-TaqMan® appears suitable in both endemic settings though is only implementable if resources permit.,In low-transmission settings, SEA-ELISA remains the method of choice to evidence an absence infection.,We discuss the pros and cons of each method concluding that future surveillance of intestinal schistosomiasis would benefit from a flexible, context-specific approach both in choice and application of each diagnostic method, rather than a single one-size fits all approach.

Schistosomiasis and soil-transmitted helminthiasis (STH) are widely distributed in Cameroon.,Although mass drug administration (MDA) of mebendazole is implemented nationwide, treatment with praziquantel was so far limited to the three northern regions and few health districts in the southern part of Cameroon, based on previous mapping conducted 25 years ago.,To update the disease distribution map and determine where treatment with praziquantel should be extended, mapping surveys were conducted in three of the seven southern regions of Cameroon, i.e.,Centre, East and West.,Parasitological surveys were conducted in April-May 2010 in selected schools in all 63 health districts of the three targeted regions, using appropriate research methodologies, i.e.,Kato-Katz and urine filtration.,The results showed significant variation of schistosomiasis and STH prevalence between schools, villages, districts and regions.,Schistosoma mansoni was the most prevalent schistosome species, with an overall prevalence of 5.53%, followed by S. haematobium (1.72%) and S. guineensis (0.14%).,The overall prevalence of schistosomiasis across the three regions was 7.31% (95% CI: 6.86-7.77%).,The prevalence for Ascaris lumbricoides was 11.48 (95% CI: 10.93-12.04%), Trichuris trichiura 18.22% (95% CI: 17.56-18.90%) and hookworms 1.55% (95% CI: 1.35-1.78%), with an overall STH prevalence of 24.10% (95% CI: 23.36-24.85%) across the three regions.,STH was more prevalent in the East region (46.57%; 95% CI: 44.41-48.75%) in comparison to the Centre (25.12; 95% CI: 24.10-26.17%) and West (10.49%; 95% CI: 9.57-11.51%) regions.,In comparison to previous data, the results showed an increase of schistosomiasis transmission in several health districts, whereas there was a significant decline of STH infections.,Based on the prevalence data, the continuation of annual or bi-annual MDA for STH is recommended, as well as an extension of praziquantel in identified moderate and high risk communities for schistosomiasis.

Malaria control is mainly based on indoor residual spraying and insecticide-treated bed nets.,The efficacy of these tools depends on the behaviour of mosquitoes, which varies by species.,With resistance to insecticides, mosquitoes adapt their behaviour to ensure their survival and reproduction.,The aim of this study was to assess the biting behaviour of Anopheles funestus after the implementation of long-lasting insecticidal nets (LLINs).,A study was conducted in Dielmo, a rural Senegalese village, after a second massive deployment of LLINs in July 2011.,Adult mosquitoes were collected by human landing catch and by pyrethrum spray catch monthly between July 2011 and April 2013.,Anophelines were identified by stereomicroscope and sub-species by PCR.,The presence of circumsporozoite protein of Plasmodium falciparum and the blood meal origin were detected by ELISA.,Anopheles funestus showed a behavioural change in biting activity after introduction of LLINs, remaining anthropophilic and endophilic, while adopting diurnal feeding, essentially on humans.,Six times more An. funestus were captured in broad daylight than at night.,Only one infected mosquito was found during day capture.,The mean of day CSP rate was 1.28% while no positive An. funestus was found in night captures.,Mosquito behaviour is an essential component for assessing vectorial capacity to transmit malaria.,The emergence of new behavioural patterns of mosquitoes may significantly increase the risk for malaria transmission and represents a new challenge for malaria control.,Additional vector control strategies are, therefore, necessary.

Global maps, in particular those based on vector distributions, have long been used to help visualise the global extent of malaria.,Few, however, have been created with the support of a comprehensive and extensive evidence-based approach.,Here we describe the generation of a global map of the dominant vector species (DVS) of malaria that makes use of predicted distribution maps for individual species or species complexes.,Our global map highlights the spatial variability in the complexity of the vector situation.,In Africa, An. gambiae, An. arabiensis and An. funestus are co-dominant across much of the continent, whereas in the Asian-Pacific region there is a highly complex situation with multi-species coexistence and variable species dominance.,The competence of the mapping methodology to accurately portray DVS distributions is discussed.,The comprehensive and contemporary database of species-specific spatial occurrence (currently available on request) will be made directly available via the Malaria Atlas Project (MAP) website from early 2012.

In the era of malaria elimination and eradication, drug-based and vaccine-based approaches to reduce malaria transmission are receiving greater attention.,Such interventions require assays that reliably measure the transmission of Plasmodium from humans to Anopheles mosquitoes.,We compared two commonly used mosquito feeding assay procedures: direct skin feeding assays and membrane feeding assays.,Three conditions under which membrane feeding assays are performed were examined: assays with i) whole blood, ii) blood pellets resuspended with autologous plasma of the gametocyte carrier, and iii) blood pellets resuspended with heterologous control serum.,930 transmission experiments from Cameroon, The Gambia, Mali and Senegal were included in the analyses.,Direct skin feeding assays resulted in higher mosquito infection rates compared to membrane feeding assays (odds ratio 2.39, 95% confidence interval 1.94-2.95) with evident heterogeneity between studies.,Mosquito infection rates in membrane feeding assays and direct skin feeding assays were strongly correlated (p<0.0001).,Replacing the plasma of the gametocyte donor with malaria naïve control serum resulted in higher mosquito infection rates compared to own plasma (OR 1.92, 95% CI 1.68-2.19) while the infectiousness of gametocytes may be reduced during the replacement procedure (OR 0.60, 95% CI 0.52-0.70).,Despite a higher efficiency of direct skin feeding assays, membrane feeding assays appear suitable tools to compare the infectiousness between individuals and to evaluate transmission-reducing interventions.,Several aspects of membrane feeding procedures currently lack standardization; this variability makes comparisons between laboratories challenging and should be addressed to facilitate future testing of transmission-reducing interventions.

There is renewed acknowledgement that targeting gametocytes is essential for malaria control and elimination efforts.,Simple mathematical models were fitted to data from clinical trials in order to determine the mean gametocyte circulation time and duration of gametocyte carriage in treated malaria patients.,Data were used from clinical trials from East Africa.,The first trial compared non-artemisinin combination therapy (non-ACT: sulphadoxine-pyrimethamine (SP) plus amodiaquine) and artemisinin-based combination therapy (ACT: SP plus artesunate (AS) or artemether-lumefantrine).,The second trial compared ACT (SP+AS) with ACT in combination with a single dose of primaquine (ACT-PQ: SP+AS+PQ).,Mature gametocytes were quantified in peripheral blood samples by nucleic acid sequence based amplification.,A simple deterministic compartmental model was fitted to gametocyte densities to estimate the circulation time per gametocyte; a similar model was fitted to gametocyte prevalences to estimate the duration of gametocyte carriage after efficacious treatment.,The mean circulation time of gametocytes was 4.6-6.5 days.,After non-ACT treatment, patients were estimated to carry gametocytes for an average of 55 days (95% CI 28.7 - 107.7).,ACT reduced the duration of gametocyte carriage fourfold to 13.4 days (95% CI 10.2-17.5).,Addition of PQ to ACT resulted in a further fourfold reduction of the duration of gametocyte carriage.,These findings confirm previous estimates of the circulation time of gametocytes, but indicate a much longer duration of (low density) gametocyte carriage after apparently successful clearance of asexual parasites.,ACT shortened the period of gametocyte carriage considerably, and had the most pronounced effect on mature gametocytes when combined with PQ.

The goal to eliminate malaria from the Asia-Pacific by 2030 will require the safe and widespread delivery of effective radical cure of malaria.,In October 2017, the Asia Pacific Malaria Elimination Network Vivax Working Group met to discuss the impediments to primaquine (PQ) radical cure, how these can be overcome and the methodological difficulties in assessing clinical effectiveness of radical cure.,The salient discussions of this meeting which involved 110 representatives from 18 partner countries and 21 institutional partner organizations are reported.,Context specific strategies to improve adherence are needed to increase understanding and awareness of PQ within affected communities; these must include education and health promotion programs.,Lessons learned from other disease programs highlight that a package of approaches has the greatest potential to change patient and prescriber habits, however optimizing the components of this approach and quantifying their effectiveness is challenging.,In a trial setting, the reactivity of participants results in patients altering their behaviour and creates inherent bias.,Although bias can be reduced by integrating data collection into the routine health care and surveillance systems, this comes at a cost of decreasing the detection of clinical outcomes.,Measuring adherence and the factors that relate to it, also requires an in-depth understanding of the context and the underlying sociocultural logic that supports it.,Reaching the elimination goal will require innovative approaches to improve radical cure for vivax malaria, as well as the methods to evaluate its effectiveness.

Most hematophagous insects use host odours as chemical cues.,The odour components, some physiological parameters and host attractiveness are affected by several conditions, including infection by parasites, e.g., plasmodia and, therefore, change the epidemiological scenario.,This study evaluated the attractiveness of individuals with vivax malaria before, during (7 days) and after treatment (14 days) with specific antimalarial drugs.,Mosquito attractiveness to vivax-infected patients was assessed using a vertical olfactometer using the foot as a source of body odour.,The ratio of Anopheles darlingi mosquitoes in the lower chamber of the olfactometer was used to calculate the attractiveness, and patient temperature was measured using a digital thermometer.,An increased attractiveness was found only in patients bearing vivax gametocytes during the first experiment (early infection) (P < 0.001).,Patients in the first experiment tended to have a higher body temperature, but grouping patients into fever and non-fever resulted in a higher attractiveness only in the fever group of gametocyte carriers, suggesting a synergistic effect of temperature and gametocytes in the host attractiveness to A. darlingi.,Gametocyte presence and fever in vivax malaria patients increased short distance host attractiveness to An. darlingi.

Approximately 2 billion people currently suffer from intestinal helminth infections, which are typically chronic in nature and result in growth retardation, vitamin A deficiency, anemia and poor cognitive function.,Such chronicity results from co-evolution between helminths and their mammalian hosts; however, the molecular mechanisms by which these organisms avert immune rejection are not clear.,We have found that the natural murine helminth, Heligmosomoides polygyrus bakeri (Hp) elicits the secretion of IL-1β in vivo and in vitro and that this cytokine is critical for shaping a mucosal environment suited to helminth chronicity.,Indeed in mice deficient for IL-1β (IL-1β−/−), or treated with the soluble IL-1βR antagonist, Anakinra, helminth infection results in enhanced type 2 immunity and accelerated parasite expulsion.,IL-1β acts to decrease production of IL-25 and IL-33 at early time points following infection and parasite rejection was determined to require IL-25.,Taken together, these data indicate that Hp promotes the release of host-derived IL-1β that suppresses the release of innate cytokines, resulting in suboptimal type 2 immunity and allowing pathogen chronicity.

Helminth parasites are of considerable medical and economic importance.,Studies of the immune response against helminths are of great interest in understanding interactions between the host immune system and parasites.,Effector immune mechanisms against tissue-dwelling helminths and helminths localized in the lumen of organs, and their regulation, are reviewed.,Helminth infections are characterized by an association of Th2-like and Treg responses.,Worms are able to persist in the host and are mainly responsible for chronic infection despite a strong immune response developed by the parasitized host.,Two types of protection against the parasite, namely, premune and partial immunities, have been described.,Immune responses against helminths can also participate in pathogenesis.,Th2/Treg-like immunomodulation allows the survival of both host and parasite by controlling immunopathologic disorders and parasite persistence.,Consequences of the modified Th2-like responses on co-infection, vaccination, and inflammatory diseases are discussed.

The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis.,It is estimated that almost 2 billion people worldwide are infected with helminths.,Whilst the WHO treatment guidelines for helminth infections are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis.,However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy.,Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being “predisposed” to infection, and target treatment at them.,The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, human-based papers investigating predisposition to helminth infections published up to October 31st, 2017.,The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised.,Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed.,In total, 43 papers were identified, summarising results from 34 different studies in 23 countries.,Consistent evidence of predisposition to infection with certain species of human helminth was identified.,Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults.,Females were found to be more predisposed to A. lumbricoides infection than were males.,Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum.,Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition.,Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species.,This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species.,However, further research is needed to identify reasons for the reported differences between demographic groups.,Molecular epidemiological methods associated with whole genome sequencing to determine ‘who infects whom’ may shed more light on the factors generating predisposition.,The online version of this article (10.1186/s13071-018-2656-4) contains supplementary material, which is available to authorized users.

Parasitic infections affect tens of millions of pregnant women worldwide, and directly or indirectly lead to a spectrum of adverse maternal and fetal/placental effects.,The objective of this study was to assess the prevalence of intestinal parasite infections and associated risk factors among pregnant women attending antenatal care center in Felege Hiwot Referral Hospital, Bahir Dar city, northwest Ethiopia.,A cross-sectional hospital based study was conducted from November 2013 to January 2014 among 384 pregnant women.,Stool samples were examined for the presence of trophozoites, cysts, oocysts, and ova using direct, formal-ether sedimentation, and modified Ziehl-Neelsen techniques.,An overall prevalence of 31.5 % intestinal parasite infections was recorded.,Eight different species of intestinal parasites were found: two protozoan and six helminth species.,The highest prevalence was due to Giardia lamblia (13.3 %) followed by Entamoeba histolytica/dispar (7.8 %), hookworm (5.5 %), Ascaris lumbricoides (2.9 %), Schistosoma mansoni (2.9 %), Strongyloides stercoralis (1.6 %), Taenia spp.,(0.8 %), and Hymenolepis nana (0.3 %).,A relatively high prevalence of intestinal parasite infections was observed among pregnant women.,Routine stool examination and provision of health education are required for early medical intervention that would affect the pregnant mothers and their foetuses.,The online version of this article (doi:10.1186/s12879-016-1859-6) contains supplementary material, which is available to authorized users.

There is a long history of considering the constituent components of malaria risk and the malaria transmission cycle via the use of mathematical models, yet strategic planning in endemic countries tends not to take full advantage of available disease intelligence to tailor interventions.,National malaria programmes typically make operational decisions about where to implement vector control and surveillance activities based upon simple categorizations of annual parasite incidence.,With technological advances, an enormous opportunity exists to better target specific malaria interventions to the places where they will have greatest impact by mapping and evaluating metrics related to a variety of risk components, each of which describes a different facet of the transmission cycle.,Here, these components and their implications for operational decision-making are reviewed.,For each component, related mappable malaria metrics are also described which may be measured and evaluated by malaria programmes seeking to better understand the determinants of malaria risk.,Implementing tailored programmes based on knowledge of the heterogeneous distribution of the drivers of malaria transmission rather than only consideration of traditional metrics such as case incidence has the potential to result in substantial improvements in decision-making.,As programmes improve their ability to prioritize their available tools to the places where evidence suggests they will be most effective, elimination aspirations may become increasingly feasible.

As more regions approach malaria elimination, understanding how different interventions interact to reduce transmission becomes critical.,The Lake Kariba area of Southern Province, Zambia, is part of a multi-country elimination effort and presents a particular challenge as it is an interconnected region of variable transmission intensities.,In 2012-13, six rounds of mass test-and-treat drug campaigns were carried out in the Lake Kariba region.,A spatial dynamical model of malaria transmission in the Lake Kariba area, with transmission and climate modeled at the village scale, was calibrated to the 2012-13 prevalence survey data, with case management rates, insecticide-treated net usage, and drug campaign coverage informed by surveillance.,The model captured the spatio-temporal trends of decline and rebound in malaria prevalence in 2012-13 at the village scale.,Various interventions implemented between 2016-22 were simulated to compare their effects on reducing regional transmission and achieving and maintaining elimination through 2030.,Simulations predict that elimination requires sustaining high coverage with vector control over several years.,When vector control measures are well-implemented, targeted mass drug campaigns in high-burden areas further increase the likelihood of elimination, although drug campaigns cannot compensate for insufficient vector control.,If infections are regularly imported from outside the region into highly receptive areas, vector control must be maintained within the region until importations cease.,Elimination in the Lake Kariba region is possible, although human movement both within and from outside the region risk damaging the success of elimination programs.

Carriage and density of gametocytes, the transmission stages of malaria parasites, are determined for predicting the infectiousness of humans to mosquitoes.,This measure is used for evaluating interventions that aim at reducing malaria transmission.,Gametocytes need to be detected by amplification of stage-specific transcripts, which requires RNA-preserving blood sampling.,For simultaneous, highly sensitive quantification of both, blood stages and gametocytes, we have compared and optimized different strategies for field and laboratory procedures in a cross sectional survey in 315 5-9 yr old children from Papua New Guinea. qRT-PCR was performed for gametocyte markers pfs25 and pvs25, Plasmodium species prevalence was determined by targeting both, 18S rRNA genes and transcripts.,RNA-based parasite detection resulted in a P. falciparum positivity of 24.1%; of these 40.8% carried gametocytes.,P. vivax positivity was 38.4%, with 38.0% of these carrying gametocytes.,Sensitivity of DNA-based parasite detection was substantially lower with 14.1% for P. falciparum and 19.6% for P. vivax.,Using the lower DNA-based prevalence of asexual stages as a denominator increased the percentage of gametocyte-positive infections to 59.1% for P. falciparum and 52.4% for P. vivax.,For studies requiring highly sensitive and simultaneous quantification of sexual and asexual parasite stages, 18S rRNA transcript-based detection saves efforts and costs.,RNA-based positivity is considerably higher than other methods.,On the other hand, DNA-based parasite quantification is robust and permits comparison with other globally generated molecular prevalence data.,Molecular monitoring of low density asexual and sexual parasitaemia will support the evaluation of effects of up-scaled antimalarial intervention programs and can also inform about small scale spatial variability in transmission intensity.

Considerable declines in malaria have accompanied increased funding for control since the year 2000, but historical failures to maintain gains against the disease underscore the fragility of these successes.,Although malaria transmission can be suppressed by effective control measures, in the absence of active intervention malaria will return to an intrinsic equilibrium determined by factors related to ecology, efficiency of mosquito vectors, and socioeconomic characteristics.,Understanding where and why resurgence has occurred historically can help current and future malaria control programmes avoid the mistakes of the past.,A systematic review of the literature was conducted to identify historical malaria resurgence events.,All suggested causes of these events were categorized according to whether they were related to weakened malaria control programmes, increased potential for malaria transmission, or technical obstacles like resistance.,The review identified 75 resurgence events in 61 countries, occurring from the 1930s through the 2000s.,Almost all resurgence events (68/75 = 91%) were attributed at least in part to the weakening of malaria control programmes for a variety of reasons, of which resource constraints were the most common (39/68 = 57%).,Over half of the events (44/75 = 59%) were attributed in part to increases in the intrinsic potential for malaria transmission, while only 24/75 (32%) were attributed to vector or drug resistance.,Given that most malaria resurgences have been linked to weakening of control programmes, there is an urgent need to develop practical solutions to the financial and operational threats to effectively sustaining today’s successful malaria control programmes.

Despite mass drug administration programmes with praziquantel, the prevalence of schistosomiasis remains high.,A vaccine is urgently needed to control transmission of this debilitating disease.,As some promising schistosomiasis vaccine candidates are moving through pre-clinical and clinical testing, we review the immunological challenges that these vaccine candidates may encounter in transitioning through the clinical trial phases in endemic settings.,Prior exposure of the target population to schistosomes and other infections may impact vaccine response and efficacy and therefore requires considerable attention.,Schistosomes are known for their potential to induce T-reg/IL-10 mediated immune suppression in populations which are chronically infected.,Moreover, endemicity of schistosomiasis is focal whereby target and trial populations may exhibit several degrees of prior exposure as well as in utero exposure which may increase heterogeneity of vaccine responses.,The age dependent distribution of exposure and development of acquired immunity, and general differences in the baseline immunological profile, adds to the complexity of selecting suitable trial populations.,Similarly, prior or concurrent infections with other parasitic helminths, viral and bacterial infections, may alter immunological responses.,Consequently, treatment of co-infections may benefit the immunogenicity of vaccines and may be considered despite logistical challenges.,On the other hand, viral infections leave a life-long immunological imprint on the human host.,Screening for serostatus may be needed to facilitate interpretation of vaccine responses.,Co-delivery of schistosome vaccines with PZQ is attractive from a perspective of implementation but may complicate the immunogenicity of schistosomiasis vaccines.,Several studies have reported PZQ treatment to induce both transient and long-term immuno-modulatory effects as a result of tegument destruction, worm killing and subsequent exposure of worm antigens to the host immune system.,These in turn may augment or antagonize vaccine immunogenicity.,Understanding the complex immunological interactions between vaccine, co-infections or prior exposure is essential in early stages of clinical development to facilitate phase 3 clinical trial design and implementation policies.,Besides well-designed studies in different target populations using schistosome candidate vaccines or other vaccines as models, controlled human infections could also help identify markers of immune protection in populations with different disease and immunological backgrounds.

Urinary schistosomiasis, the result of infection by Schistosoma haematobium (Sh), remains a major global health concern.,A schistosome vaccine could represent a breakthrough in schistosomiasis control strategies, which are presently based on treatment with praziquantel (PZQ).,We report the safety and efficacy of the vaccine candidate recombinant 28-kDa glutathione S-transferase of Sh (rSh28GST) designated as Bilhvax, in a phase 3 trial conducted in Senegal.,After clearance of their ongoing schistosomiasis infection with two doses of PZQ, 250 children aged 6-9 years were randomized to receive three subcutaneous injections of either rSh28GST/Alhydrogel (Bilhvax group) or Alhydrogel alone (control group) at week 0 (W0), W4, and W8 and then a booster at W52 (one year after the first injection).,PZQ treatment was given at W44, according to previous phase 2 results.,The primary endpoint of the analysis was efficacy, evaluated as a delay of recurrence of urinary schistosomiasis, defined by a microhematuria associated with at least one living Sh egg in urine from baseline to W152.,During the 152-week follow-up period, there was no difference between study arms in the incidence of serious adverse events.,The median follow-up time for subjects without recurrence was 22.9 months for the Bilhvax group and 18.8 months for the control group (log-rank p = 0.27).,At W152, 108 children had experienced at least one recurrence in the Bilhvax group versus 112 in the control group.,Specific immunoglobulin (Ig)G1, IgG2, and IgG4, but not IgG3 or IgA titers, were increased in the vaccine group.,While Bilhvax was immunogenic and well tolerated by infected children, a sufficient efficacy was not reached.,The lack of effect may be the result of several factors, including interference by individual PZQ treatments administered each time a child was found infected, or the chosen vaccine-injection regimen favoring blocking IgG4 rather than protective IgG3 antibodies.,These observations contrasting with results obtained in experimental models will help in the design of future trials.,ClinicalTrials.gov NCT 00870649

Since 2014, a considerable increase in Plasmodium vivax malaria has been observed in Germany.,The majority of cases was seen in Eritrean refugees.,All patients with P. vivax malaria admitted to the University Medical Centre Hamburg-Eppendorf Germany from 2011 until August 2015 were retrospectively identified by the hospital coding system and data was matched with records from the laboratory diagnostics unit of the Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.,Between May 2014 and August 2015, 37 cases were reported in newly-arrived Eritrean refugees at the University Medical Centre Hamburg-Eppendorf, Germany.,Relapses occurred due to difficulties in procurement of primaquine.,Countries hosting Eritrean refugees need to be aware of vivax malaria occurring in this group and the risk of autochthonous cases due to local transmission by indigenous, vector competent Anopheles species.

Primaquine is the only generally available anti-malarial that prevents relapse in vivax and ovale malaria, and the only potent gametocytocide in falciparum malaria.,Primaquine becomes increasingly important as malaria-endemic countries move towards elimination, and although it is widely recommended, it is commonly not given to malaria patients because of haemolytic toxicity in subjects who are glucose-6-phosphate dehydrogenase (G6PD) deficient (gene frequency typically 3-30% in malaria endemic areas; >180 different genetic variants).,In six decades of primaquine use in approximately 200 million people, 14 deaths have been reported.,Confining the estimate to reports with known denominators gives an estimated mortality of one in 621,428 (upper 95% CI: one in 407,807).,All but one death followed multiple dosing to prevent vivax malaria relapse.,Review of dose-response relationships and clinical trials of primaquine in G6PD deficiency suggests that the currently recommended WHO single low dose (0.25 mg base/kg) to block falciparum malaria transmission confers a very low risk of haemolytic toxicity.

Long-lasting insecticidal nets (LLINs) and indoor residual spraying of insecticide (IRS) are the primary vector control interventions used to prevent malaria in Africa.,Although both interventions are effective in some settings, high-quality evidence is rarely available to evaluate their effectiveness following deployment by a national malaria control program.,In Uganda, we measured changes in key malaria indicators following universal LLIN distribution in three sites, with the addition of IRS at one of these sites.,Comprehensive malaria surveillance was conducted from October 1, 2011, to March 31, 2016, in three sub-counties with relatively low (Walukuba), moderate (Kihihi), and high transmission (Nagongera).,Between 2013 and 2014, universal LLIN distribution campaigns were conducted in all sites, and in December 2014, IRS with the carbamate bendiocarb was initiated in Nagongera.,High-quality surveillance evaluated malaria metrics and mosquito exposure before and after interventions through (a) enhanced health-facility-based surveillance to estimate malaria test positivity rate (TPR), expressed as the number testing positive for malaria/number tested for malaria (number of children tested for malaria: Walukuba = 42,833, Kihihi = 28,790, and Nagongera = 38,690); (b) cohort studies to estimate the incidence of malaria, expressed as the number of episodes per person-year [PPY] at risk (number of children observed: Walukuba = 340, Kihihi = 380, and Nagongera = 361); and (c) entomology surveys to estimate household-level human biting rate (HBR), expressed as the number of female Anopheles mosquitoes collected per house-night of collection (number of households observed: Walukuba = 117, Kihihi = 107, and Nagongera = 107).,The LLIN distribution campaign substantially increased LLIN coverage levels at the three sites to between 65.0% and 95.5% of households with at least one LLIN.,In Walukuba, over the 28-mo post-intervention period, universal LLIN distribution was associated with no change in the incidence of malaria (0.39 episodes PPY pre-intervention versus 0.20 post-intervention; adjusted rate ratio [aRR] = 1.02, 95% CI 0.36-2.91, p = 0.97) and non-significant reductions in the TPR (26.5% pre-intervention versus 26.2% post-intervention; aRR = 0.70, 95% CI 0.46-1.06, p = 0.09) and HBR (1.07 mosquitoes per house-night pre-intervention versus 0.71 post-intervention; aRR = 0.41, 95% CI 0.14-1.18, p = 0.10).,In Kihihi, over the 21-mo post-intervention period, universal LLIN distribution was associated with a reduction in the incidence of malaria (1.77 pre-intervention versus 1.89 post-intervention; aRR = 0.65, 95% CI 0.43-0.98, p = 0.04) but no significant change in the TPR (49.3% pre-intervention versus 45.9% post-intervention; aRR = 0.83, 95% 0.58-1.18, p = 0.30) or HBR (4.06 pre-intervention versus 2.44 post-intervention; aRR = 0.71, 95% CI 0.30-1.64, p = 0.40).,In Nagongera, over the 12-mo post-intervention period, universal LLIN distribution was associated with a reduction in the TPR (45.3% pre-intervention versus 36.5% post-intervention; aRR = 0.82, 95% CI 0.76-0.88, p < 0.001) but no significant change in the incidence of malaria (2.82 pre-intervention versus 3.28 post-intervention; aRR = 1.10, 95% 0.76-1.59, p = 0.60) or HBR (41.04 pre-intervention versus 20.15 post-intervention; aRR = 0.87, 95% CI 0.31-2.47, p = 0.80).,The addition of three rounds of IRS at ~6-mo intervals in Nagongera was followed by clear decreases in all outcomes: incidence of malaria (3.25 pre-intervention versus 0.63 post-intervention; aRR = 0.13, 95% CI 0.07-0.27, p < 0.001), TPR (37.8% pre-intervention versus 15.0% post-intervention; aRR = 0.54, 95% CI 0.49-0.60, p < 0.001), and HBR (18.71 pre-intervention versus 3.23 post-intervention; aRR = 0.29, 95% CI 0.17-0.50, p < 0.001).,High levels of pyrethroid resistance were documented at all three study sites.,Limitations of the study included the observational study design, the lack of contemporaneous control groups, and that the interventions were implemented under programmatic conditions.,Universal distribution of LLINs at three sites with varying transmission intensity was associated with modest declines in the burden of malaria for some indicators, but the addition of IRS at the highest transmission site was associated with a marked decline in the burden of malaria for all indicators.,In highly endemic areas of Africa with widespread pyrethroid resistance, IRS using alternative insecticide formulations may be needed to achieve substantial gains in malaria control.,In this prospective observational study, Grant Dorsey and colleagues measure changes in malaria burden after long-lasting insecticidal net distribution and indoor residual spraying at three sites of in Uganda.

The National Malaria Control Program (NMCP) has been using pirimiphos methyl for the first time for indoor residual spraying (IRS) in Benin.,The first round was a success with a significant decrease of entomological indicators of malaria transmission in the treated districts.,We present the results of the entomological impact on malaria transmission.,Entomologic parameters in the control area were compared with those in intervention sites.,Mosquito collections were carried out in three districts in the Atacora-Dongo region of which two were treated with pirimiphos methyl (Actellic 50EC) (Tanguiéta and Kouandé) and the untreated (Copargo) served as control.,Anopheles gambiae s.l. populations were sampled monthly by human landing catch.,In addition, window exit traps and pyrethrum spray catches were performed to assess exophagic behavior of Anopheles vectors.,In the three districts, mosquito collections were organized to follow the impact of pirimiphos methyl IRS on malaria transmission and possible changes in the behavior of mosquitoes.,The residual activity of pirimiphos methyl in the treated walls was also assessed using WHO bioassay test.,A significant reduction (94.25%) in human biting rate was recorded in treated districts where an inhabitant received less than 1 bite of An. gambiae per night.,During this same time, the entomological inoculation rate (EIR) dramatically declined in the treated area (99.24% reduction).,We also noted a significant reduction in longevity of the vectors and an increase in exophily induced by pirimiphos methyl on An. gambiae.,However, no significant impact was found on the blood feeding rate.,Otherwise, the low residual activity of Actellic 50 EC, which is three months, is a disadvantage.,Pirimiphos methyl was found to be effective for IRS in Benin.,However, because of the low persistence of Actellic 50EC used in this study on the treated walls, the recourse to another more residual formulation of pirimiphos methyl is required.

Despite the progress achieved in scaling-up mass drug administration (MDA) for lymphatic filariasis (LF) in Ghana, communities with persistent LF still exist even after 10 years of community treatment.,To understand the reasons for persistence, we conducted a study to assess the status of disease elimination and understand the adherence to interventions including MDA and insecticide treated nets.,We conducted a parasitological and epidemiological cross-sectional study in adults from eight villages still under MDA in the Northern Region savannah and the coastal Western Region of the country.,Prevalence of filarial antigen ranged 0 to 32.4% and in five villages the prevalence of night blood microfilaria (mf) was above 1%, ranging from 0 to 5.7%.,Median mf density was 67 mf/ml (range: 10-3,560).,LF antigen positivity was positively associated with male sex but negatively associated with participating in MDA the previous year.,Male sex was also associated with a decreased probability of participating in MDA.,A stochastic model (TRANSFIL) was used to assess the expected microfilaria prevalence under different MDA coverage scenarios using historical data on one community in the Western Region.,In this example, the model simulations suggested that the slow decline in mf prevalence is what we would expect given high baseline prevalence and a high correlation between MDA adherence from year to year, despite high MDA coverage.,There is a need for an integrated quantitative and qualitative research approach to identify the variations in prevalence, associated risk factors and intervention coverage and use levels between and within regions and districts.,Such knowledge will help target resources and enhance surveillance to the communities most at risk and to reach the 2020 LF elimination goals in Ghana.

There is an increased focus on whether mass drug administration (MDA) programmes alone can interrupt the transmission of soil-transmitted helminths (STH).,Mathematical models can be used to model these interventions and are increasingly being implemented to inform investigators about expected trial outcome and the choice of optimum study design.,One key factor is the choice of threshold for detecting elimination.,However, there are currently no thresholds defined for STH regarding breaking transmission.,We develop a simulation of an elimination study, based on the DeWorm3 project, using an individual-based stochastic disease transmission model in conjunction with models of MDA, sampling, diagnostics and the construction of study clusters.,The simulation is then used to analyse the relationship between the study end-point elimination threshold and whether elimination is achieved in the long term within the model.,We analyse the quality of a range of statistics in terms of the positive predictive values (PPV) and how they depend on a range of covariates, including threshold values, baseline prevalence, measurement time point and how clusters are constructed.,End-point infection prevalence performs well in discriminating between villages that achieve interruption of transmission and those that do not, although the quality of the threshold is sensitive to baseline prevalence and threshold value.,Optimal post-treatment prevalence threshold value for determining elimination is in the range 2% or less when the baseline prevalence range is broad.,For multiple clusters of communities, both the probability of elimination and the ability of thresholds to detect it are strongly dependent on the size of the cluster and the size distribution of the constituent communities.,Number of communities in a cluster is a key indicator of probability of elimination and PPV.,Extending the time, post-study endpoint, at which the threshold statistic is measured improves PPV value in discriminating between eliminating clusters and those that bounce back.,The probability of elimination and PPV are very sensitive to baseline prevalence for individual communities.,However, most studies and programmes are constructed on the basis of clusters.,Since elimination occurs within smaller population sub-units, the construction of clusters introduces new sensitivities for elimination threshold values to cluster size and the underlying population structure.,Study simulation offers an opportunity to investigate key sources of sensitivity for elimination studies and programme designs in advance and to tailor interventions to prevailing local or national conditions.

Effective targeting and evaluation of interventions that protect against adult malaria vectors requires an understanding of how gaps in personal protection arise.,An improved understanding of human and mosquito behaviour, and how they overlap in time and space, is critical to estimating the impact of insecticide-treated nets (ITNs) and determining when and where supplemental personal protection tools are needed.,Methods for weighting estimates of human exposure to biting Anopheles mosquitoes according to where people spend their time were first developed over half a century ago.,However, crude indoor and outdoor biting rates are still commonly interpreted as indicative of human-vector contact patterns without any adjustment for human behaviour or the personal protection effects of ITNs.,A small number of human behavioural variables capturing the distribution of human populations indoors and outdoors, whether they are awake or asleep, and if and when they use an ITN over the course of the night, can enable a more accurate representation of human biting exposure patterns.,However, to date no clear guidance is available on what data should be collected, what indicators should be reported, or how they should be calculated.,This article presents an integrated perspective on relevant indicators of human-vector interactions, the critical entomological and human behavioural data elements required to quantify human-vector interactions, and recommendations for collecting and analysing such data.,If collected and used consistently, this information can contribute to an improved understanding of how malaria transmission persists in the context of current intervention tools, how exposure patterns may change as new vector control tools are introduced, and the potential impact and limitations of these tools.,This article is intended to consolidate understanding around work on this topic to date and provide a consistent framework for building upon it.,Additional work is needed to address remaining questions, including further development and validation of methods for entomological and human behavioural data collection and analysis.

Long-lasting insecticidal hammocks (LLIHs) are being evaluated as an additional malaria prevention tool in settings where standard control strategies have a limited impact.,This is the case among the Ra-glai ethnic minority communities of Ninh Thuan, one of the forested and mountainous provinces of Central Vietnam where malaria morbidity persist due to the sylvatic nature of the main malaria vector An. dirus and the dependence of the population on the forest for subsistence - as is the case for many impoverished ethnic minorities in Southeast Asia.,A social science study was carried out ancillary to a community-based cluster randomized trial on the effectiveness of LLIHs to control forest malaria.,The social science research strategy consisted of a mixed methods study triangulating qualitative data from focused ethnography and quantitative data collected during a malariometric cross-sectional survey on a random sample of 2,045 study participants.,To meet work requirements during the labor intensive malaria transmission and rainy season, Ra-glai slash and burn farmers combine living in government supported villages along the road with a second home at their fields located in the forest.,LLIH use was evaluated in both locations.,During daytime, LLIH use at village level was reported by 69.3% of all respondents, and in forest fields this was 73.2%.,In the evening, 54.1% used the LLIHs in the villages, while at the fields this was 20.7%.,At night, LLIH use was minimal, regardless of the location (village 4.4%; forest 6.4%).,Despite the free distribution of insecticide-treated nets (ITNs) and LLIHs, around half the local population remains largely unprotected when sleeping in their forest plot huts.,In order to tackle forest malaria more effectively, control policies should explicitly target forest fields where ethnic minority farmers are more vulnerable to malaria.

Vector-biting behaviour is important for vector-borne disease (VBD) epidemiology.,The proportion of blood meals taken on humans (the human blood index, HBI), is a component of the biting rate per vector on humans in VBD transmission models.,Humans are the definitive host of Onchocerca volvulus, but the simuliid vectors feed on a range of animals and HBI is a key indicator of the potential for human onchocerciasis transmission.,Ghana has a diversity of Simulium damnosum complex members, which are likely to vary in their HBIs, an important consideration for parameterization of onchocerciasis control and elimination models.,Host-seeking and ovipositing S. damnosum (sensu lato) (s.l.) were collected from seven villages in four Ghanaian regions.,Taxa were morphologically and molecularly identified.,Blood meals from individually stored blackfly abdomens were used for DNA profiling, to identify previous host choice.,Household, domestic animal, wild mammal and bird surveys were performed to estimate the density and diversity of potential blood hosts of blackflies.,A total of 11,107 abdomens of simuliid females (which would have obtained blood meal(s) previously) were tested, with blood meals successfully amplified in 3,772 (34 %).,A single-host species was identified in 2,857 (75.7 %) of the blood meals, of which 2,162 (75.7 %) were human.,Simulium soubrense Beffa form, S. squamosum C and S. sanctipauli Pra form were the most anthropophagic (HBI = 0.92, 0.86 and 0.70, respectively); S. squamosum E, S. yahense and S. damnosum (sensu stricto) (s.s.),/S. sirbanum were the most zoophagic (HBI = 0.44, 0.53 and 0.63, respectively).,The degree of anthropophagy decreased (but not statistically significantly) with increasing ratio of non-human/human blood hosts.,Vector to human ratios ranged from 139 to 1,198 blackflies/person.,DNA profiling can successfully identify blood meals from host-seeking and ovipositing blackflies.,Host choice varies according to sibling species, season and capture site/method.,There was no evidence that HBI is vector and/or host density dependent.,Transmission breakpoints will vary among locations due to differing cytospecies compositions and vector abundances.,The online version of this article (doi:10.1186/s13071-016-1703-2) contains supplementary material, which is available to authorized users.

Ghana is renowned for its sibling species diversity of the Simulium damnosum complex, vectors of Onchocerca volvulus.,Detailed entomological knowledge becomes a priority as onchocerciasis control policy has shifted from morbidity reduction to elimination of infection.,To date, understanding of transmission dynamics of O. volvulus has been mainly based on S. damnosum sensu stricto (s.s.) data.,We aim to elucidate bionomic features of vector species of importance for onchocerciasis elimination efforts.,We collected S. damnosum sensu lato from seven villages in four Ghanaian regions between 2009 and 2011, using standard vector collection, and human- and cattle-baited tents.,Taxa were identified using morphological and molecular techniques.,Monthly biting rates (MBR), parous rates and monthly parous biting rates (MPBR) are reported by locality, season, trapping method and hour of collection for each species.,S. damnosum s.s.,/S. sirbanum were collected at Asubende and Agborlekame, both savannah villages.,A range of species was caught in the Volta region (forest-savannah mosaic) and Gyankobaa (forest), with S. squamosum or S. sanctipauli being the predominant species, respectively.,In Bosomase (southern forest region) only S. sanctipauli was collected in the 2009 wet season, but in the 2010 dry season S. yahense was also caught.,MBRs ranged from 714 bites/person/month at Agborlekame (100% S. damnosum s.s.,/S. sirbanum) to 8,586 bites/person/month at Pillar 83/Djodji (98.5% S. squamosum).,MBRs were higher in the wet season.,In contrast, parous rates were higher in the dry season (41.8% vs.,18.4%), resulting in higher MPBRs in the dry season.,Daily host-seeking activity of S. damnosum s.s.,/S. sirbanum was bimodal, whilst S. squamosum and S. sanctipauli had unimodal afternoon peaks.,The bionomic differences between sibling species of the S. damnosum complex need to be taken into account when designing entomological monitoring protocols for interventions and parameterising mathematical models for onchocerciasis control and elimination.,The online version of this article (doi:10.1186/s13071-014-0511-9) contains supplementary material, which is available to authorized users.

Background.,Asymptomatic parasitemia is common even in areas of low seasonal malaria transmission, but the true proportion of the population infected has not been estimated previously because of the limited sensitivity of available detection methods.,Methods.,Cross-sectional malaria surveys were conducted in areas of low seasonal transmission along the border between eastern Myanmar and northwestern Thailand and in western Cambodia.,DNA was quantitated by an ultrasensitive polymerase chain reaction (uPCR) assay (limit of accurate detection, 22 parasites/mL) to characterize parasite density distributions for Plasmodium falciparum and Plasmodium vivax, and the proportions of undetected infections were imputed.,Results.,The prevalence of asymptomatic malaria as determined by uPCR was 27.5% (1303 of 4740 people tested).,Both P. vivax and P. falciparum density distributions were unimodal and log normal, with modal values well within the quantifiable range.,The estimated proportions of all parasitemic individuals identified by uPCR were >70% among individuals infected with P. falciparum and >85% among those infected with P. vivax.,Overall, 83% of infections were predicted to be P. vivax infections, 13% were predicted to be P. falciparum infections, and 4% were predicted to be mixed infections.,Geometric mean parasite densities were similar; 5601 P. vivax parasites/mL and 5158 P. falciparum parasites/mL.,Conclusions.,This uPCR method identified most infected individuals in malaria-endemic areas.,Malaria parasitemia persists in humans at levels that optimize the probability of generating transmissible gametocyte densities without causing illness.

The duration of infection is fundamental to the epidemiological behaviour of any infectious disease, but remains one of the most poorly understood aspects of malaria.,In endemic areas, the malaria parasite Plasmodium falciparum can cause both acute, severe infections and asymptomatic, chronic infections through its interaction with the host immune system.,Frequent superinfection and massive parasite genetic diversity make it extremely difficult to accurately measure the distribution of infection lengths, complicating the estimation of basic epidemiological parameters and the prediction of the impact of interventions.,Mathematical models have qualitatively reproduced parasite dynamics early during infection, but reproducing long-lived chronic infections remains much more challenging.,Here, we construct a model of infection dynamics to examine the consequences of common biological assumptions for the generation of chronicity and the impact of co-infection.,We find that although a combination of host and parasite heterogeneities are capable of generating chronic infections, they do so only under restricted parameter choices.,Furthermore, under biologically plausible assumptions, co-infection of parasite genotypes can alter the course of infection of both the resident and co-infecting strain in complex non-intuitive ways.,We outline the most important puzzles for within-host models of malaria arising from our analysis, and their implications for malaria epidemiology and control.

Artemisinin-based combination therapies (ACTs) are globally the first-line treatment for uncomplicated falciparum malaria and new compounds will not be available within the next few years.,Artemisinin-resistant Plasmodium falciparum emerged over a decade ago in the Greater Mekong Subregion (GMS) and, compounded by ACT partner drug resistance, has caused significant ACT treatment failure.,This review provides an update on the epidemiology, and mechanisms of artemisinin resistance and approaches to counter multidrug-resistant falciparum malaria.,An aggressive malaria elimination programme in the GMS has helped prevent the spread of drug resistance to neighbouring countries.,However, parasites carrying artemisinin resistance-associated mutations in the P. falciparum Kelch13 gene (pfk13) have now emerged independently in multiple locations elsewhere in Asia, Africa and South America.,Notably, artemisinin-resistant infections with parasites carrying the pfk13 R561H mutation have emerged and spread in Rwanda.,Enhancing the geographic coverage of surveillance for resistance will be key to ensure prompt detection of emerging resistance in order to implement effective countermeasures without delay.,Treatment strategies designed to prevent the emergence and spread of multidrug resistance must be considered, including deployment of triple drug combination therapies and multiple first-line therapies.

The emergence and spread of drug-resistant Plasmodium falciparum impedes global efforts to control and eliminate malaria.,For decades, treatment relied on chloroquine (CQ), a safe and affordable 4-aminoquinoline that was highly effective against intra-erythrocytic asexual blood-stage parasites, until resistance arose in Southeast Asia and South America and spread worldwide1.,Clinical resistance to the chemically-related current first-line combination drug piperaquine (PPQ) has now emerged regionally, thwarting its efficacy2.,Resistance to CQ and PPQ has been associated with distinct sets of point mutations in the P. falciparum chloroquine resistance transporter PfCRT, a 49 kDa member of the drug/metabolite transporter (DMT) superfamily that traverses the membrane of the parasite’s acidic digestive vacuole (DV)3-9.,Here we present the 3.2 Å structure of the PfCRT isoform from CQ-resistant, PPQ-sensitive South American 7G8 parasites, using single-particle cryo-electron microscopy (cryo-EM) and fragment antigen-binding (Fab) technology.,Mutations contributing to CQ and PPQ resistance localize primarily to moderately-conserved sites on distinct helices lining a central negatively-charged cavity, implicating this as the principal site of interaction with positively-charged CQ and PPQ.,Binding and transport studies reveal that the 7G8 isoform binds both drugs with comparable affinities, with these drugs being mutually competitive.,This isoform transports CQ in a membrane potential- and pH-dependent manner, consistent with an active efflux mechanism driving CQ resistance5, but does not transport PPQ.,Functional studies on the newly emerging PfCRT F145I and C350R mutations, associated with decreased PPQ susceptibility in Asia and South America respectively6,9, reveal their ability to mediate PPQ transport in 7G8 variant proteins and to confer resistance in gene-edited parasites.,Structural, functional and in silico analyses suggest distinct mechanistic features mediating CQ and PPQ resistance in PfCRT variants.,These data provide the first atomic-level insights into the molecular mechanism of this key mediator of antimalarial treatment failures.

Dirofilaria immitis and Dirofilaria repens are transmitted by bloodsucking culicid mosquitoes belonging to Culex, Aedes, Ochlerotatus, Anopheles and Mansonia genera.,The detection of filarioids in mosquitoes for assessing distribution of vectors and/or of pathogens in a given area (also known as “xenomonitoring”), when based on individual dissection of wild-caught female mosquitoes is time consuming and hardly applicable in large epidemiological surveys.,Our study aimed to evaluate the recently developed duplex real-time PCR for screening large number of culicids and to assess their positivity for D. immitis and D. repens in an area where both species are endemic.,A duplex real-time PCR was used to detect and differentiate D. immitis and D. repens in mosquitoes collected in six provinces of the Veneto region using 43 carbon dioxide-baited traps under the frame of an entomological surveillance program to monitor the vectors of West Nile disease.,From early May till October 2010, unfed female mosquitoes (n = 40,892) were captured in 20 selected sites.,Mosquitoes identified as Culex pipiens, Ochlerotatus caspius, Aedes vexans and Culex modestus were grouped into 995 pools according to species, day and site of collection (from minimum of 1 to maximum of 57).,Out of 955 pools, 23 (2.41 %) scored positive for Dirofilaria spp. of which, 21 (2.2 %) for D. immitis and two (0.21 %) for D. repens.,An overall Estimated Rate of Infection (ERI) of 0.06 % was recorded, being higher in Och. caspius and Ae. vexans (i.e., 0.18 % and 0.14 %, respectively).,At least one mosquito pool was positive for Dirofilaria spp. in each province with the highest ERI recorded in Vicenza and Padova provinces (i.e., 0.42% and 0.16 %, respectively).,Mosquitoes collected in all provinces were positive for D. immitis whereas, only two (i.e., Padova and Rovigo) provinces scored positive for D. repens.,All mosquito species, except for Cx. modestus, were positive for D. immitis, whereas D. repens was only found in Cx. pipiens.,The results suggest that both Dirofilaria species are endemic and may occur in sympatry in the examined area.,The molecular approach herein used represents a powerful tool for surveillance programs of D. immitis and D. repens in the culicid vectors towards a better understanding of the epidemiology of the infections they cause and their seasonal transmission patterns.

Research is now focused on identification of sensitive and specific diagnostic tests for early identification of schistosomal infection and evaluation of chemotherapy in field situations in China.,This study compared loop-mediated isothermal amplification (LAMP) with conventional PCR as DNA-based diagnostic techniques for the early detection of schistosomal DNA and the evaluation of chemotherapy.,The results showed that both PCR and LAMP assays targeting a 301 base pair (bp) sequence of the highly repetitive retrotransposon, SjR2, amplified DNA from schistosomes but were unable to distinguish between schistosome species.,LAMP and conventional PCR were shown to amplify the target sequence of the SjR2-pCR2.1 recombinant plasmid template with limits of detection of 10-4 ng and 10-2 ng, respectively, thus demonstrating the superior sensitivity of the LAMP method.,Schistosoma japonicum DNA was detected in all serum samples obtained from the three experimental groups at 1 week post-infection by LAMP assay, while the rate of detection by conventional PCR ranged from 50% to 66%.,The potential application of PCR and LAMP assays for the evaluation of artesunate and praziquantel chemotherapy was investigated.,PCR was shown to be less sensitive for detection of schistosomal DNA in drug-treated rabbit sera than the LAMP method.,The data presented here indicate that LAMP is suitable for the detection of early infection in the groups primarily infected with Schistosoma japonicum, such as migrants, travellers, military personnel and the younger age groups.,However, it is less suitable for evaluation of the efficacy of chemotherapy in the early stages because of its high sensitivity.

In Colombia, the cutaneous leishmaniasis (CL) is the most common manifestation across the army personnel.,Hence, it is mandatory to determine the species associated with the disease as well as the association with the clinical traits.,A total of 273 samples of male patients with CL were included in the study and clinical data of the patients was studied.,PCR and sequencing analyses (Cytb and HSP70 genes) were performed to identify the species and the intra-specific genetic variability.,A georeferenced database was constructed to identify the spatial distribution of Leishmania species isolated.,The identification of five species of Leishmania that circulate in the areas where army personnel are deployed is described.,Predominant infecting Leishmania species corresponds to L. braziliensis (61.1%), followed by Leishmania panamensis (33.5%), with a high distribution of both species at geographical and municipal level.,The species L. guyanensis, L. mexicana and L. lainsoni were also detected at lower frequency.,We also showed the identification of different genotypes within L. braziliensis and L. panamensis.,In conclusion, we identified the Leishmania species circulating in the areas where Colombian army personnel are deployed, as well as the high intra-specific genetic variability of L. braziliensis and L. panamensis and how these genotypes are distributed at the geographic level.

Leishmaniasis is a highly diverse group of diseases caused by kinetoplastid of the genus Leishmania.,These parasites are taxonomically diverse, with human pathogenic species separated into two subgenera according to their development site inside the alimentary tract of the sand fly insect vector.,The disease encompasses a variable spectrum of clinical manifestations with tegumentary or visceral symptoms.,Among the causative species in Brazil, Leishmania (Leishmania) amazonensis is an important etiological agent of human cutaneous leishmaniasis that accounts for more than 8% of all cases in endemic regions.,L.,(L.) amazonensis is generally found in the north and northeast regions of Brazil.,Here, we report the first isolation of L.,(L.) amazonensis from dogs with clinical manifestations of visceral leishmaniasis in Governador Valadares, an endemic focus in the southeastern Brazilian State of Minas Gerais where L.,(L.) infantum is also endemic.,These isolates were characterized in terms of SNPs, chromosome and gene copy number variations, confirming that they are closely related to a previously sequenced isolate obtained in 1973 from the typical Northern range of this species.,The results presented in this article will increase our knowledge of L.,(L.) amazonensis-specific adaptations to infection, parasite survival and the transmission of this Amazonian species in a new endemic area of Brazil.

•2448 microsatellite loci were identified within 83 Mb of F. hepatica genome sequence data.,•A panel of 15 polymorphic loci were developed and validated using genomic DNA from 46 parasites.,•The panel was developed and optimised as a multiplex PCR protocol.,•All loci could be amplified from several F. hepatica lifecycle stages with the multiplex approach.,2448 microsatellite loci were identified within 83 Mb of F. hepatica genome sequence data.,A panel of 15 polymorphic loci were developed and validated using genomic DNA from 46 parasites.,The panel was developed and optimised as a multiplex PCR protocol.,All loci could be amplified from several F. hepatica lifecycle stages with the multiplex approach.,The liver fluke, Fasciola hepatica is an economically important pathogen of sheep and cattle and has been described by the WHO as a re-emerging zoonosis.,Control is heavily reliant on the use of drugs, particularly triclabendazole and as a result resistance has now emerged.,The population structure of F. hepatica is not well known, yet it can impact on host-parasite interactions and parasite control with drugs, particularly regarding the spread of triclabendazole resistance.,We have identified 2448 potential microsatellites from 83 Mb of F. hepatica genome sequence using msatfinder.,Thirty-five loci were developed and optimised for microsatellite PCR, resulting in a panel of 15 polymorphic loci, with a range of three to 15 alleles.,This panel was validated on genomic DNA from 46 adult F. hepatica; 38 liver flukes sourced from a Northwest abattoir, UK and 8 liver flukes from an established isolate (Shrewsbury; Ridgeway Research).,Evidence for null alleles was found at four loci (Fh_1, Fh_8, Fh_13 and Fh_14), which showed markedly higher levels of homozygosity than the remaining 11 loci.,Of the 38 liver flukes isolated from cattle livers (n = 10) at the abattoir, 37 genotypes were identified.,Using a multiplex approach all 15 loci could be amplified from several life cycle stages that typically yield low amounts of DNA, including metacercariae, the infective life cycle stage present on pasture, highlighting the utility of this multiplex microsatellite panel.,This study reports the largest panel of microsatellite markers available to date for population studies of F. hepatica and the first multiplex panel of microsatellite markers that can be used for several life cycle stages.

Opisthorchiasis is a neglected, tropical disease caused by the carcinogenic Asian liver fluke, Opisthorchis viverrini.,This hepatobiliary disease is linked to malignant cancer (cholangiocarcinoma, CCA) and affects millions of people in Asia.,No vaccine is available, and only one drug (praziquantel) is used against the parasite.,Little is known about O. viverrini biology and the diseases that it causes.,Here we characterize the draft genome (634.5 Mb) and transcriptomes of O. viverrini, elucidate how this fluke survives in the hostile environment within the bile duct and show that metabolic pathways in the parasite are highly adapted to a lipid-rich diet from bile and/or cholangiocytes.,We also provide additional evidence that O. viverrini and other flukes secrete proteins that directly modulate host cell proliferation.,Our molecular resources now underpin profound explorations of opisthorchiasis/CCA and the design of new interventions.,The Asian liver fluke is a parasitic worm that is linked to an increased risk of malignant cancer.,Here, the authors sequence the draft genome and transcriptome of this fluke and provide insight into how the species has adapted to be able to survive in the bile duct.

Virulence of the most deadly malaria parasite Plasmodium falciparum is linked to the variant surface antigen PfEMP1, which is encoded by about 60 var genes per parasite genome.,Although the expression of particular variants has been associated with different clinical outcomes, little is known about var gene expression at the onset of infection.,By analyzing controlled human malaria infections via quantitative real-time PCR, we show that parasite populations from 18 volunteers expressed virtually identical transcript patterns that were dominated by the subtelomeric var gene group B and, to a lesser extent, group A.,Furthermore, major changes in composition and frequency of var gene transcripts were detected between the parental parasite culture that was used to infect mosquitoes and Plasmodia recovered from infected volunteers, suggesting that P. falciparum resets its var gene expression during mosquito passage and starts with the broad expression of a specific subset of var genes when entering the human blood phase.

Many questions remain about P. falciparum within-host dynamics, immunity, and transmission-issues that may affect public health campaign planning.,These gaps in knowledge concern the distribution of durations of malaria infections, determination of peak parasitemia during acute infection, the relationships among gametocytes and immune responses and infectiousness to mosquitoes, and the effect of antigenic structure on reinfection outcomes.,The present model of intra-host dynamics of P. falciparum implements detailed representations of parasite and immune dynamics, with structures based on minimal extrapolations from first-principles biology in its foundations.,The model is designed to quickly and readily accommodate gains in mechanistic understanding and to evaluate effects of alternative biological hypothesis through in silico experiments.,Simulations follow the parasite from the liver-stage through the detailed asexual cycle to clearance while tracking gametocyte populations.,The modeled immune system includes innate inflammatory and specific antibody responses to a repertoire of antigens.,The mechanistic focus provides clear explanations for the structure of the distribution of infection durations through the interaction of antigenic variation and innate and adaptive immunity.,Infectiousness to mosquitoes appears to be determined not only by the density of gametocytes but also by the level of inflammatory cytokines, which harmonizes an extensive series of study results.,Finally, pre-existing immunity can either decrease or increase the duration of infections upon reinfection, depending on the degree of overlap in antigenic repertoires and the strength of the pre-existing immunity.

Although evidence suggests that T cells are critical for immunity to malaria, reliable T cell correlates of exposure to and protection from malaria among children living in endemic areas are lacking.,We used multiparameter flow cytometry to perform a detailed functional characterization of malaria-specific T cells in 78 four-year-old children enrolled in a longitudinal cohort study in Tororo, Uganda, a highly malaria-endemic region.,More than 1800 episodes of malaria were observed in this cohort, with no cases of severe malaria.,We quantified production of IFNγ, TNFα, and IL-10 (alone or in combination) by malaria-specific T cells, and analyzed the relationship of this response to past and future malaria incidence.,CD4+ T cell responses were measurable in nearly all children, with the majority of children having CD4+ T cells producing both IFNγ and IL-10 in response to malaria-infected red blood cells.,Frequencies of IFNγ/IL10 co-producing CD4+ T cells, which express the Th1 transcription factor T-bet, were significantly higher in children with ≥2 prior episodes/year compared to children with <2 episodes/year (P<0.001) and inversely correlated with duration since malaria (Rho = −0.39, P<0.001).,Notably, frequencies of IFNγ/IL10 co-producing cells were not associated with protection from future malaria after controlling for prior malaria incidence.,In contrast, children with <2 prior episodes/year were significantly more likely to exhibit antigen-specific production of TNFα without IL-10 (P = 0.003).,While TNFα-producing CD4+ T cells were not independently associated with future protection, the absence of cells producing this inflammatory cytokine was associated with the phenotype of asymptomatic infection.,Together these data indicate that the functional phenotype of the malaria-specific T cell response is heavily influenced by malaria exposure intensity, with IFNγ/IL10 co-producing CD4+ T cells dominating this response among highly exposed children.,These CD4+ T cells may play important modulatory roles in the development of antimalarial immunity.

In areas mesoendemic for malaria transmission, symptomatic individuals play a significant role as reservoirs for malaria infection.,Understanding the pathogenesis of symptomatic malaria is important in devising tools for augmenting malaria control.,In this study, the effect of TLR9 polymorphisms on susceptibility to symptomatic malaria was investigated among Ghanaian children.,Four hundred and twenty nine (429) healthy Ghanaian children, aged three to eleven years (3-11 years), were enrolled into a cohort study and actively followed up for symptomatic malaria for one year.,Four TLR9 single nucleotide polymorphisms (SNPs) namely: rs187084 (C-1486 T), rs5743836(C-1237 T), rs352139 (G + 1174A) and rs352140 (G + 2848A) were genotyped by direct sequencing, and their attributable and relative risks for symptomatic malaria determined.,TLR9 haplotypes were inferred using the PHASE software and analysed for the risk of symptomatic malaria.,A luciferase assay was performed to investigate whether the TLR9 haplotypes influence TLR9 promoter activity.,The rs352139 GG genotype showed a significantly increased relative risk of 4.8 for symptomatic malaria (P = 0.0024) and a higher mean parasitaemia (P = 0.04).,Conversely, the rs352140 GG genotype showed a significantly reduced relative risk of 0.34 (P = 0.048).,TLR9 haplotypes analyses showed that TTAG haplotype was significantly associated with reduced relative risk of 0.2 for symptomatic malaria (P = 4×10-6) and a lower mean parasitaemia (0.007), while CTGA haplotype had an increased relative risk of 3.3 (P = 0.005).,Functional luciferase reporter gene expression assay revealed that the TTA haplotype had a significantly higher promoter activity than the CCG, CTG and TCG haplotypes.,Taken together, these findings indicate a significant association of TLR9 gene polymorphisms with symptomatic malaria among Ghanaian children in Dangme-West district.

Malaria morbidity and mortality has declined in recent years in a number of settings.,The ability to describe changes in malaria transmission associated with these declines is important in terms of assessing the potential effects of control interventions, and for monitoring and evaluation purposes.,Data from five cross-sectional surveys conducted in Farafenni and surrounding villages on the north bank of River Gambia between 1988 and 2011 were compiled.,Antibody responses to MSP-119 were measured in samples from all surveys, data were normalized and expressed as seroprevalence and seroconversion rates (SCR) using different mathematical models.,Results showed declines in serological metrics with seroprevalence in children aged one to 5 years dropping from 19 % (95 % CI 15-23 %) in 1988 to 1 % (0-2 %) in 2011 (p value for trend in proportions < 0.001) and the SCR dropping from 0.069 year−1 (0.059-0.080) to 0.022 year−1 (0.017-0.028; p = 0.004).,The serological data were consistent with previously described drops in both parasite prevalence in children aged 1-5 years (62 %, 57-66 %, in 1988 to 2 %, 0-4 %, in 2011; p < 0.001), and all-cause under five mortality rates (37 per 1000 person-years, 34-41, in 1990 to 17, 15-19, in 2006; p = 0.059).,This analysis shows accurate reconstruction of historical malaria transmission patterns in the Farafenni area using anti-malarial antibody responses.,Demonstrating congruence between serological measures, and conventional clinical and parasitological measures suggests broader utility for serology in monitoring and evaluation of malaria transmission.,The online version of this article (doi:10.1186/s12936-015-0939-1) contains supplementary material, which is available to authorized users.

In order to control and eliminate malaria, areas of on-going transmission need to be identified and targeted for malaria control interventions.,Immediately following intense interventions, malaria transmission can become more heterogeneous if interventions are more successful in some areas than others.,Bioko Island, Equatorial Guinea, has been subject to comprehensive malaria control interventions since 2004.,This has resulted in substantial reductions in the parasite burden, although this drop has not been uniform across the island.,In 2008, filter paper blood samples were collected from 7387 people in a cross-sectional study incorporating 18 sentinel sites across Bioko, Equatorial Guinea.,Antibodies were measured to P. falciparum Apical Membrane Antigen-1 (AMA-1) by Enzyme Linked Immunosorbent Assay (ELISA).,Age-specific seropositivity rates were used to estimate seroconversion rates (SCR).,Analysis indicated there had been at least a 60% decline in SCR in four out of five regions on the island.,Changes in SCR showed a high degree of congruence with changes in parasite rate (PR) and with regional reductions in all cause child mortality.,The mean age adjusted concentration of anti-AMA-1 antibodies was mapped to identify areas where individual antibody responses were higher than expected.,This approach confirmed the North West of the island as a major focus of continuing infection and an area where control interventions need to be concentrated or re-evaluated.,Both SCR and PR revealed heterogeneity in malaria transmission and demonstrated the variable effectiveness of malaria control measures.,This work confirms the utility of serological analysis as an adjunct measure for monitoring transmission.,Age-specific seroprevalence based evidence of changes in transmission over time will be of particular value when no baseline data are available.,Importantly, SCR data provide additional evidence to link malaria control activities to contemporaneous reductions in all-cause child mortality.

Malaria is a major public health problem in Zambia with an estimated 4 million confirmed cases and 2389 deaths reported in 2015.,Efforts to reduce the incidence of malaria are often undermined by a number of factors such as human mobility which may lead to introduction of imported infections.,The aim of this study was to establish the burden of malaria attributed to human mobility in Lusaka district and identify factors associated with malaria importation among residents of Lusaka district.,A cross sectional study was conducted in five randomly selected health facilities in Lusaka district from November 2015 to February 2016.,Data was collected from 260 patients who presented with malaria and whose status was confirmed by rapid diagnostic test or microscopy.,Each confirmed malaria case was interviewed using a structured questionnaire to establish their demographic characteristics, travel history and preventive measures.,Travel history was used as a proxy to classify cases as either imported or local.,Residency was also used as a secondary proxy for importation to compare characteristics of residents vs non-residents in relation to malaria importation.,Logistic regression was used to determine factors associated with malaria importation among residents of Lusaka district.,Out of 260 cases, 94.2% were classified as imported cases based on participants’ travel history.,There were 131 (50.4%) males and 129 (49.6%) females.,Age distribution ranged from 0 to 68 years with a median age of 15 years (IQR 8-27).,Imported cases came from all the ten provinces of Zambia with the Copperbelt Province being the highest contributor (41%).,Of all imported cases, use of prophylaxis was found to be highly protective [AOR = 0.22 (95% CI 0.06-0.82); p-value = 0.024].,Other factors that significantly influence malaria transmission and importation by residents include duration of stay in a highly endemic region [AOR = 1.25 (95% CI 1.09-1.44); p-value = 0.001] and frequency of travel [AOR = 3.71 (95% CI 1.26-10.84); p-value = 0.017].,Human mobility has influenced malaria transmission in Lusaka district through a number of factors by importing infections.,This leads to onward transmission and poses a challenge to malaria elimination and control.,However, taking of prophylaxis is highly protective and must be highly recommended.

Malaria remains a problem for many countries classified as malaria free through cases imported from endemic regions.,Imported cases to non-endemic countries often result in delays in diagnosis, are expensive to treat, and can sometimes cause secondary local transmission.,The movement of malaria in endemic countries has also contributed to the spread of drug resistance and threatens long-term eradication goals.,Here we focused on quantifying the international movements of malaria to improve our understanding of these phenomena and facilitate the design of mitigation strategies.,In this meta-analysis, we studied the database of publicly available nationally reported statistics on imported malaria in the past 10 years, covering more than 50 000 individual cases.,We obtained data from 40 non-endemic countries and recorded the geographical variations.,Infection movements were strongly skewed towards a small number of high-traffic routes between 2005 and 2015, with the west Africa region accounting for 56% (13 947/24 941) of all imported cases to non-endemic countries with a reported travel destination, and France and the UK receiving the highest number of cases, with more than 4000 reported cases per year on average.,Countries strongly linked by movements of imported cases are grouped by historical, language, and travel ties.,There is strong spatial clustering of plasmodium species types.,The architecture of the air network, historical ties, demographics of travellers, and malaria endemicity contribute to highly heterogeneous patterns of numbers, routes, and species compositions of parasites transported.,With global malaria eradication on the international agenda, malaria control altering local transmission, and the threat of drug resistance, understanding these patterns and their drivers is increasing in importance.,Bill & Melinda Gates Foundation, National Institutes of Health, UK Medical Research Council, UK Department for International Development, Wellcome Trust.

The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP.,Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women (ISTp) is an alternative approach.,An open, individually randomized, non-inferiority trial of IPTp-SP versus ISTp was conducted in 5,354 primi- or secundigravidae in four West African countries with a low prevalence of resistance to SP (The Gambia, Mali, Burkina Faso and Ghana).,Women in the IPTp-SP group received SP on two or three occasions whilst women in the ISTp group were screened two or three times with a RDT and treated if positive for malaria with artemether-lumefantrine (AL).,ISTp-AL was non-inferior to IPTp-SP in preventing low birth weight (LBW), anemia and placental malaria, the primary trial endpoints.,The prevalence of LBW was 15.1% and 15.6% in the IPTp-SP and ISTp-AL groups respectively (OR = 1.03 [95% CI: 0.88, 1.22]).,The mean hemoglobin concentration at the last clinic attendance before delivery was 10.97g/dL and 10.94g/dL in the IPTp-SP and ISTp-AL groups respectively (mean difference: -0.03 g/dL [95% CI: -0.13, +0.06]).,Active malaria infection of the placenta was found in 24.5% and in 24.2% of women in the IPTp-SP and ISTp-AL groups respectively (OR = 0.95 [95% CI 0.81, 1.12]).,More women in the ISTp-AL than in the IPTp-SP group presented with malaria parasitemia between routine antenatal clinics (310 vs 182 episodes, rate difference: 49.4 per 1,000 pregnancies [95% CI 30.5, 68.3], but the number of hospital admissions for malaria was similar in the two groups.,Despite low levels of resistance to SP in the study areas, ISTp-AL performed as well as IPTp-SP.,In the absence of an effective alternative medication to SP for IPTp, ISTp-AL is a potential alternative to IPTp in areas where SP resistance is high.,It may also have a role in areas where malaria transmission is low and for the prevention of malaria in HIV positive women receiving cotrimoxazole prophylaxis in whom SP is contraindicated.,ClinicalTrials.gov NCT01084213,Pan African Clinical trials Registry PACT201202000272122

Malaria parasite prevalence in endemic populations is an essential indicator for monitoring the progress of malaria control, and has traditionally been assessed by microscopy.,However, surveys increasingly use sensitive molecular methods that detect higher numbers of infected individuals, questioning our understanding of the true infection burden and resources required to reduce it.,Here we analyse a series of data sets to characterize the distribution and epidemiological factors associated with low-density, submicroscopic infections.,We show that submicroscopic parasite carriage is common in adults, in low-endemic settings and in chronic infections.,We find a strong, non-linear relationship between microscopy and PCR prevalence in population surveys (n=106), and provide a tool to relate these measures.,When transmission reaches very low levels, submicroscopic carriers are estimated to be the source of 20-50% of all human-to-mosquito transmissions.,Our findings challenge the idea that individuals with little previous malaria exposure have insufficient immunity to control parasitaemia and suggest a role for molecular screening.,Malaria can persist at levels that escape detection by standard microscopy, but can be detected by PCR.,Okell et al. now show that rates of submicroscopic infection can be predicted using more widely available microscopy data, and are most epidemiologically significant in areas with low malaria transmission.

Plasmodium knowlesi (Pk) is a malaria parasite that naturally infects macaque monkeys in Southeast Asia.,Pk malaria, the zoonosis transmitted from the infected monkeys to the humans by Anopheles mosquito vectors, is now a serious health problem in Malaysian Borneo.,To create a strategic plan to control Pk malaria, it is important to estimate the occurrence of the disease correctly.,The rise of Pk malaria has been explained as being due to ecological changes, especially deforestation.,In this research, we analysed the time-series satellite images of MODIS (MODerate-resolution Imaging Spectroradiometer) of the Kudat Peninsula in Sabah and created the “Pk risk map” on which the Land-Use and Land-Cover (LULC) information was visualised.,The case number of Pk malaria of a village appeared to have a correlation with the quantity of two specific LULC classes, the mosaic landscape of oil palm groves and the nearby land-use patches of dense forest, surrounding the village.,Applying a Poisson multivariate regression with a generalised linear mixture model (GLMM), the occurrence of Pk malaria cases was estimated from the population and the quantified LULC distribution on the map.,The obtained estimations explained the real case numbers well, when the contribution of another risk factor, possibly the occupation of the villagers, is considered.,This implies that the occurrence of the Pk malaria cases of a village can be predictable from the population of the village and the LULC distribution shown around it on the map.,The Pk risk map will help to assess the Pk malaria risk distributions quantitatively and to discover the hidden key factors behind the spread of this zoonosis.

Two cases of Plasmodium knowlesi infection in humans were identified in Cambodia by 3 molecular detection assays and sequencing.,This finding confirms the widespread distribution of P. knowlesi malaria in humans in Southeast Asia.,Further wide-scale studies are required to assess the public health relevance of this zoonotic malaria parasite.

Distinct Trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response of Chagas disease.,However, typing strategies for genotype-specific serodiagnosis of Chagas disease are still unavailable and requires standardization for practical application.,In this study, an innovative TcI/TcVI/TcII Chagas Flow ATE-IgG2a technique was developed with applicability for universal and genotype-specific diagnosis of T. cruzi infection.,For this purpose, the reactivity of serum samples (percentage of positive fluorescent parasites-PPFP) obtained from mice chronically infected with TcI/Colombiana, TcVI/CL or TcII/Y strain as well as non-infected controls were determined using amastigote-AMA, trypomastigote-TRYPO and epimastigote-EPI in parallel batches of TcI, TcVI and TcII target antigens.,Data demonstrated that “α-TcII-TRYPO/1:500, cut-off/PPFP = 20%” presented an excellent performance for universal diagnosis of T. cruzi infection (AUC = 1.0, Se and Sp = 100%).,The combined set of attributes “α-TcI-TRYPO/1:4,000, cut-off/PPFP = 50%”, “α-TcII-AMA/1:1,000, cut-off/PPFP = 40%” and “α-TcVI-EPI/1:1,000, cut-off/PPFP = 45%” showed good performance to segregate infections with TcI/Colombiana, TcVI/CL or TcII/Y strain.,Overall, hosts infected with TcI/Colombiana and TcII/Y strains displayed opposite patterns of reactivity with “α-TcI TRYPO” and “α-TcII AMA”.,Hosts infected with TcVI/CL strain showed a typical interweaved distribution pattern.,The method presented a good performance for genotype-specific diagnosis, with global accuracy of 69% when the population/prototype scenario include TcI, TcVI and TcII infections and 94% when comprise only TcI and TcII infections.,This study also proposes a receiver operating reactivity panel, providing a feasible tool to classify serum samples from hosts infected with distinct T. cruzi genotypes, supporting the potential of this method for universal and genotype-specific diagnosis of T. cruzi infection.

Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity.,Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one called TcBat are used for strain typing.,Beyond the debate concerning this classification, this systematic review has attempted to provide an inventory by compiling the results of 137 articles that have used it.,A total of 6,343 DTU identifications were analyzed according to the geographical and host origins.,Ninety-one percent of the data available is linked to South America.,This sample, although not free of potential bias, nevertheless provides today’s picture of T. cruzi genetic diversity that is closest to reality.,DTUs were genotyped from 158 species, including 42 vector species.,Remarkably, TcI predominated in the overall sample (around 60%), in both sylvatic and domestic cycles.,This DTU known to present a high genetic diversity, is very widely distributed geographically, compatible with a long-term evolution.,The marsupial is thought to be its most ancestral host and the Gran Chaco region the place of its putative origin.,TcII was rarely sampled (9.6%), absent, or extremely rare in North and Central America, and more frequently identified in domestic cycles than in sylvatic cycles.,It has a low genetic diversity and has probably found refuge in some mammal species.,It is thought to originate in the south-Amazon area.,TcIII and TcIV were also rarely sampled.,They showed substantial genetic diversity and are thought to be composed of possible polyphyletic subgroups.,Even if they are mostly associated with sylvatic transmission cycles, a total of 150 human infections with these DTUs have been reported.,TcV and TcVI are clearly associated with domestic transmission cycles.,Less than 10% of these DTUs were identified together in sylvatic hosts.,They are thought to originate in the Gran Chaco region, where they are predominant and where putative parents exist (TcII and TcIII).,Trends in host-DTU specificities exist, but generally it seems that the complexity of the cycles and the participation of numerous vectors and mammal hosts in a shared area, maintains DTU diversity.

Long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) interventions can reduce malaria transmission by targeting mosquitoes when they feed upon sleeping humans and/or rest inside houses, livestock shelters or other man-made structures.,However, many malaria vector species can maintain robust transmission, despite high coverage of LLINs/IRS containing insecticides to which they are physiologically fully susceptible, because they exhibit one or more behaviours that define the biological limits of achievable impact with these interventions: (1) Natural or insecticide-induced avoidance of contact with treated surfaces within houses and early exit from them, thus minimizing exposure hazard of vectors which feed indoors upon humans; (2) Feeding upon humans when they are active and unprotected outdoors, thereby attenuating personal protection and any consequent community-wide suppression of transmission; (3) Feeding upon animals, thus minimizing contact with insecticides targeted at humans or houses; (4) Resting outdoors, away from insecticide-treated surfaces of nets, walls and roofs.,Residual malaria transmission is, therefore, defined as all forms of transmission that can persist after achieving full universal coverage with effective LLINs and/or IRS containing active ingredients to which local vector populations are fully susceptible.,Residual transmission is sufficiently intense across most of the tropics to render malaria elimination infeasible without new or improved vector control methods.,Many novel or improved vector control strategies to address residual transmission are emerging that either: (1) Enhance control of adult vectors that enter houses to feed and/or rest by killing, repelling or excluding them; (2) Kill or repel adult mosquitoes when they attack people outdoors; (3) Kill adult mosquitoes when they attack livestock; (4) Kill adult mosquitoes when they feed upon sugar or; (5) Kill immature mosquitoes in aquatic habitats.,To date, none of these options has sufficient supporting evidence to justify full-scale programmatic implementation.,Concerted investment in their rigorous selection, development and evaluation is required over the coming decade to enable control and, ultimately, elimination of residual malaria transmission.,In the meantime, national programmes may assess options for addressing residual transmission under programmatic conditions through pilot studies with strong monitoring, evaluation and operational research components, similar to the Onchocerciasis Control Programme.

The Malaria Eradication Research Agenda (malERA) Consultative Group on Drugs present a research and development agenda to ensure that appropriate drugs are available for use in malaria eradication.,Antimalarial drugs will be essential tools at all stages of malaria elimination along the path towards eradication, including the early control or “attack” phase to drive down transmission and the later stages of maintaining interruption of transmission, preventing reintroduction of malaria, and eliminating the last residual foci of infection.,Drugs will continue to be used to treat acute malaria illness and prevent complications in vulnerable groups, but better drugs are needed for elimination-specific indications such as mass treatment, curing asymptomatic infections, curing relapsing liver stages, and preventing transmission.,The ideal malaria eradication drug is a coformulated drug combination suitable for mass administration that can be administered in a single encounter at infrequent intervals and that results in radical cure of all life cycle stages of all five malaria species infecting humans.,Short of this optimal goal, highly desirable drugs might have limitations such as targeting only one or two parasite species, the priorities being Plasmodium falciparum and Plasmodium vivax.,The malaria research agenda for eradication should include research aimed at developing such drugs and research to develop situation-specific strategies for using both current and future drugs to interrupt malaria transmission.

Toxoplasma gondii is a ubiquitous, intracellular parasite that envelops its parasitophorous vacuole with a protein-laden membrane (PVM).,The PVM is critical for interactions with the infected host cell, such as nutrient transport and immune defense.,Only a few parasite and host proteins have so far been identified on the host-cytosolic side of the Toxoplasma PVM.,We report here the use of human foreskin fibroblasts expressing the proximity-labeling enzyme miniTurbo, fused to a domain that targets it to this face of the PVM, in combination with quantitative proteomics to specifically identify proteins present at this interface.,Out of numerous human and parasite proteins with candidate PVM localization, we validate three parasite proteins (TGGT1_269950 [GRA61], TGGT1_215360 [GRA62], and TGGT1_217530 [GRA63]) and four new host proteins (PDCD6IP/ALIX, PDCD6, CC2D1A, and MOSPD2) as localized to the PVM in infected human cells through immunofluorescence microscopy.,These results significantly expand our knowledge of proteins present at the Toxoplasma PVM and, given that three of the validated host proteins are components of the ESCRT (endosomal sorting complexes required for transport) machinery, they further suggest that novel biology is operating at this crucial host-pathogen interface.

Toxoplasma gondii cysts reactivate during immune deficiency and cause fatal encephalitis.,Parasite molecules that coordinate the development of acute and chronic infection are poorly characterized.,Here, we show that many intravacuolar network membrane and parasitophorous vacuole membrane-associated dense granule (GRA) proteins orchestrate the development of chronic cysts in vivo.,A subset of these GRA proteins also modulate acute virulence, and one protein that associates with the intravacuolar network membranes, namely GRA12, was identified as a major virulence factor required for parasite resistance to host gamma interferon (IFN-γ).,Our results revealed that many parasitophorous vacuole membrane and intravacuolar network membrane-associated GRA proteins are essential for successful chronic infection.,Toxoplasma gondii evades host immunity to establish a chronic infection.,Here, we assessed the role of parasitophorous vacuole (PV) membrane (PVM)- and intravacuolar network (IVN) membrane-localized dense granule (GRA) proteins in the development of acute and chronic Toxoplasma infection.,Deletion of PVM-associated GRA3, GRA7, GRA8, and GRA14 or IVN membrane-associated GRA2, GRA9, and GRA12 in the low-virulence type II Prugniaud (Pru) strain induced severe defects in the development of chronic-stage cysts in vivo without affecting the parasite growth rate or the ability to differentiate into cysts in vitro.,Acute virulence of the PruΔgra2, PruΔgra3, and PruΔgra4 mutants was reduced but not abolished.,In contrast, the PruΔgra12 mutant was avirulent in mice and PruΔgra12 parasites failed to establish a chronic infection.,High-virulence type I strain RHΔgra12 parasites also exhibited a major defect in acute virulence.,In gamma interferon (IFN-γ)-activated macrophages, type I RHΔgra12 and type II PruΔgra12 parasites resisted the coating of the PVM with host immunity-related GTPases as effectively as the parental type I RHΔku80 and type II PruΔku80 strains, respectively.,Despite this resistance, Δgra12 PVs ultimately succumbed to IFN-γ-activated host cell innate immunity.,Our findings uncover a key role for GRA12 in mediating resistance to host IFN-γ and reveal that many other IVN membrane-associated GRA proteins, as well as PVM-localized GRA proteins, play important roles in establishing chronic infection.

Plasmodium vivax has the ability to relapse from dormant parasites in the liver weeks or months after inoculation, causing further blood-stage infection and potential onward transmission.,Estimates of the force of blood-stage infections arising from primary infections and relapses are important for designing intervention strategies.,However, in endemic settings their relative contributions are unclear.,Infections are frequently asymptomatic, many individuals harbor multiple infections, and while high-resolution genotyping of blood samples enables individual infections to be distinguished, primary infections and relapses cannot be identified.,We develop a model and fit it to longitudinal genotyping data from children in Papua New Guinea to estimate the incidence and seasonality of P vivax primary infection and relapse.,The children, aged one to three years at enrolment, were followed up over 16 months with routine surveys every two months.,Blood samples were taken at the routine visits and at other times if the child was ill.,Samples positive by microscopy or a molecular method for species detection were genotyped using high-resolution capillary electrophoresis for P vivax MS16 and msp1F3, and P falciparum msp2.,The data were summarized as longitudinal patterns of success or failure to detect a genotype at each routine time-point (eg 001000001).,We assume that the seasonality of P vivax primary infection is similar to that of P falciparum since they are transmitted by the same vectors and, because P falciparum does not have the ability to relapse, the seasonality can be estimated.,Relapses occurring during the study period can be a consequence of infections occurring prior to the study: we assume that the seasonal pattern of primary infections repeats over time.,We incorporate information from parasitological and entomology studies to gain leverage for estimating the parameters, and take imperfect detection into account.,We estimate the force of P vivax primary infections to be 11.5 (10.5, 12.3) for a three-year old child per year and the mean number of relapses per infection to be 4.3 (4.0, 4.6) over 16 months.,The peak incidence of relapses occurred in the two month interval following the peak interval for primary infections: the contribution to the force of blood-stage infection from relapses is between 71% and 90% depending on the season.,Our estimates contribute to knowledge of the P vivax epidemiology and have implications for the timing of intervention strategies targeting different stages of the life cycle.

Although some malaria-control programs are beginning to combine insecticide-treated nets (ITNs) and indoor residual spraying (IRS), little is known about the effectiveness of such combinations.,We use a mathematical model to compare the effectiveness of ITNs and IRS with dichlorodiphenyltrichloroethane (DDT) or bendiocarb, applied singly and in combination, in an epidemiological setting based in Namawala, Tanzania, with Anopheles gambiae as the primary vector.,Our model indicates that although both IRS (with DDT) and ITNs provide personal protection, humans with only ITNs are better protected than those with only IRS, and suggests that high coverage of IRS with bendiocarb may interrupt transmission, as can simultaneous high coverage of ITNs and IRS with DDT.,When adding a second vector-control intervention, it is more effective to cover the unprotected population first.,Although our model includes some assumptions and approximations that remain to be addressed, these findings should be useful for prioritizing and designing future field research.

Soil-transmitted helminths (STH) are endemic in 120 countries and are associated with substantial morbidity and loss of economic productivity.,Although current WHO guidelines focus on morbidity control through mass drug administration (MDA), there is global interest in whether a strategy targeting disease elimination might be feasible in some settings.,This review summarizes the prospects for switching from control to an elimination strategy.,STH control efforts have reduced the intensity of infections in targeted populations with associated reductions in morbidity.,However, adults are not frequently targeted and remain important reservoirs for reinfection of treated children.,Recent modeling suggests that transmission interruption may be possible through expanded community-wide delivery of MDA, the feasibility of which has been demonstrated by other programs.,However, these models suggest that high levels of coverage and compliance must be achieved.,Potential challenges include the risk of prematurely dismantling STH programs and the potential increased risk of antihelminthic resistance.,Elimination of STH may offer an opportunity to eliminate substantial STH-related morbidity while reducing resource needs of neglected tropical disease programs.,Evidence from large community trials is needed to determine the feasibility of interrupting the transmission of STH in some geographic settings.

Soil transmitted helminths (STH) infect >1.5 billion people.,Mass drug administration (MDA) effectively reduces infection; however, there is evidence for rapid reinfection and risk of potential drug resistance.,We conducted a randomized controlled trial in Bangladesh (WASH Benefits, NCT01590095) to assess whether water, sanitation, hygiene and nutrition interventions, alone and combined, reduce STH in a setting with ongoing MDA.,In 2012-2013, we randomized 720 clusters of 5551 pregnant women into water treatment, sanitation, handwashing, combined water+sanitation+handwashing (WSH), nutrition, nutrition+WSH (N+WSH) or control arms.,In 2015-2016, we enrolled 7795 children, aged 2-12 years, of 4102 available women for STH follow-up and collected stool from 7187.,We enumerated STH infections with Kato-Katz.,We estimated intention-to-treat intervention effects on infection prevalence and intensity.,Participants and field staff were not blinded; laboratory technicians and data analysts were blinded.,Prevalence among controls was 36.8% for A. lumbricoides, 9.2% for hookworm and 7.5% for T. trichiura.,Most infections were low-intensity.,Compared to controls, the water intervention reduced hookworm by 31% (prevalence ratio [PR] = 0.69 (0.50,0.95), prevalence difference [PD] = -2.83 (-5.16,-0.50)) but did not affect other STH.,Sanitation improvements reduced T. trichiura by 29% (PR = 0.71 (0.52,0.98), PD = -2.17 (-4.03,-0.38)), had a similar borderline effect on hookworm and no effect on A. lumbricoides.,Handwashing and nutrition interventions did not reduce any STH.,WSH and N+WSH reduced hookworm prevalence by 29-33% (WSH: PR = 0.71 (0.52,0.99), PD = -2.63 (-4.95,-0.31); N+WSH: PR = 0.67 (0.50,0.91), PD = -3.00 (-5.14,-0.85)) and marginally reduced A. lumbricoides.,Effects on infection intensity were similar.,In a low-intensity infection setting with MDA, we found modest but sustained hookworm reduction from water treatment and combined WSH interventions.,Impacts were more pronounced on STH species with short vs. long-term environmental survival.,Our findings suggest possible waterborne transmission for hookworm.,Water treatment and sanitation improvements can augment MDA to interrupt STH transmission.,NCT01590095.

Pathogen control programs provide a valuable, but rarely exploited, opportunity to directly examine the relationship between population decline and population genetics.,We investigated the impact of an ∼12-fold decline in transmission on the population genetics of Plasmodium falciparum infections (n = 1731) sampled from four clinics on the Thai-Burma border over 10 years and genotyped using 96 genome-wide SNPs.,The most striking associated genetic change was a reduction in the frequency of infections containing multiple parasite genotypes from 63% in 2001 to 14% in 2010 (P = 3 × 10−15).,Two measures of the clonal composition of populations (genotypic richness and the β-parameter of the Pareto distribution) declined over time as more people were infected by parasites with identical multilocus genotypes, consistent with increased selfing and a reduction in the rate at which multilocus genotypes are broken apart by recombination.,We predicted that the reduction in transmission, multiple clone carriage and outbreeding would be mirrored by an increased influence of genetic drift.,However, geographical differentiation and expected heterozygosity remained stable across the sampling period.,Furthermore, Ne estimates derived from allele frequencies fluctuation between years remained high (582 to ∞) and showed no downward trend.,These results demonstrate how genetic data can compliment epidemiological assessments of infectious disease control programs.,The temporal changes in a single declining population parallel to those seen in comparisons of parasite genetics in regions of differing endemicity, strongly supporting the notion that reduced opportunity for outbreeding is the key driver of these patterns.

The human malaria parasite Plasmodium falciparum survives pressures from the host immune system and antimalarial drugs by modifying its genome.,Genetic recombination and nucleotide substitution are the two major mechanisms that the parasite employs to generate genome diversity.,A better understanding of these mechanisms may provide important information for studying parasite evolution, immune evasion and drug resistance.,Here, we used a high-density tiling array to estimate the genetic recombination rate among 32 progeny of a P. falciparum genetic cross (7G8 × GB4).,We detected 638 recombination events and constructed a high-resolution genetic map.,Comparing genetic and physical maps, we obtained an overall recombination rate of 9.6 kb per centimorgan and identified 54 candidate recombination hotspots.,Similar to centromeres in other organisms, the sequences of P. falciparum centromeres are found in chromosome regions largely devoid of recombination activity.,Motifs enriched in hotspots were also identified, including a 12-bp G/C-rich motif with 3-bp periodicity that may interact with a protein containing 11 predicted zinc finger arrays.,These results show that the P. falciparum genome has a high recombination rate, although it also follows the overall rule of meiosis in eukaryotes with an average of approximately one crossover per chromosome per meiosis.,GC-rich repetitive motifs identified in the hotspot sequences may play a role in the high recombination rate observed.,The lack of recombination activity in centromeric regions is consistent with the observations of reduced recombination near the centromeres of other organisms.

Massive implementation of malaria diagnostics in low-resource countries is regarded as a pivotal strategy in control and elimination efforts.,Although malaria rapid diagnostic tests (RDTs) are considered a viable alternative, there are still obstacles to the widespread implementation of this strategy, such as reporting constraints and lack of proper quality assurance of RDT-based programmes at point-of-care (POC).,A prospective cohort of patients, seeking routine care for febrile episodes at health centres in malaria-endemic areas of Colombia, was used to assess the diagnostic performance of a device based on smartphone technology (Deki ReaderTM, former codename “GenZero”), that assists users at POC to process RDTs.,After informed consent, patients were enrolled into the study and blood samples were collected for thick blood smear (TBS) and RDT.,The RDT results were interpreted by both visual inspection and Deki Reader device and concordance between visual and device interpretation was measured.,Microscopy corrected by real-time polymerase chain reaction (PCR) and microscopy were “gold standard” tests to assess the diagnostic performance.,In total, 1,807 patients were enrolled at seven health centres in malaria-endemic areas of Colombia.,Thirty-three Plasmodium falciparum and 100 Plasmodium vivax cases were positive by corrected microscopy.,Both sensitivity and specificity were 93.9% (95% CI 69.7-95.2) and 98.7% (95% CI 98.5-99.4) for P. falciparum, and 98.0% (95% CI 90.3-98.9) and 97.9% (95% CI 97.1-98.5) for P. vivax.,Percentage concordance between visual and device interpretation of RDT was 98.5% and 99.0% for P. vivax and P. falciparum, respectively.The RDT, when compared to TBS, showed high sensitivity and specificity for P. falciparum in both visual and device interpretation, and good overall diagnostic performance for P. vivax.,Comparison between PCR as gold standard and visual and device interpretation showed acceptable overall performance for both species.,The diagnostic performance of the Deki Reader was comparable to visual interpretation of RDTs (without significant differences) for both malaria species.,Providing standardized automated interpretation of RDTs at POC in remote areas, in addition to almost real-time reporting of cases and enabling quality control would greatly benefit large-scale implementation of RDT-based malaria diagnostic programmes.

We assessed if histidine-rich-protein-2 (HRP2) based rapid diagnostic test (RDT) remains an efficient tool for Plasmodium falciparum case detection among fever patients in Zanzibar and if primary health care workers continue to adhere to RDT results in the new epidemiological context of low malaria transmission.,Further, we evaluated the performance of RDT within the newly adopted integrated management of childhood illness (IMCI) algorithm in Zanzibar.,We enrolled 3890 patients aged ≥2 months with uncomplicated febrile illness in this health facility based observational study conducted in 12 primary health care facilities in Zanzibar, between May-July 2010.,One patient had an inconclusive RDT result.,Overall 121/3889 (3.1%) patients were RDT positive.,The highest RDT positivity rate, 32/528 (6.1%), was found in children aged 5-14 years.,RDT sensitivity and specificity against PCR was 76.5% (95% CI 69.0-83.9%) and 99.9% (95% CI 99.7-100%), and against blood smear microscopy 78.6% (95% CI 70.8-85.1%) and 99.7% (95% CI 99.6-99.9%), respectively.,All RDT positive, but only 3/3768 RDT negative patients received anti-malarial treatment.,Adherence to RDT results was thus 3887/3889 (99.9%).,RDT performed well in the IMCI algorithm with equally high adherence among children <5 years as compared with other age groups.,The sensitivity of HRP-2 based RDT in the hands of health care workers compared with both PCR and microscopy for P. falciparum case detection was relatively low, whereas adherence to test results with anti-malarial treatment was excellent.,Moreover, the results provide evidence that RDT can be reliably integrated in IMCI as a tool for improved childhood fever management.,However, the relatively low RDT sensitivity highlights the need for improved quality control of RDT use in primary health care facilities, but also for more sensitive point-of-care malaria diagnostic tools in the new epidemiological context of low malaria transmission in Zanzibar.,ClinicalTrials.gov NCT01002066

Primaquine was excreted in very low levels in the breast milk of lactating women and caused no adverse effects in their infants.,Restrictions on primaquine use in mothers breastfeeding infants at least 28 days old should be lifted.,Primaquine is the only drug providing radical cure of Plasmodium vivax malaria.,It is not recommended for breastfeeding women as it causes hemolysis in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals, and breast milk excretion and thus infant exposure are not known.,Healthy G6PD-normal breastfeeding women with previous P. vivax infection and their healthy G6PD-normal infants between 28 days and 2 years old were enrolled.,Mothers took primaquine 0.5 mg/kg/day for 14 days.,Primaquine and carboxyprimaquine concentrations were measured in maternal venous plasma, capillary plasma, and breast milk samples and infant capillary plasma samples taken on days 0, 3, 7, and 13.,In 20 mother-infant pairs, primaquine concentrations were below measurement thresholds in all but 1 infant capillary plasma sample (that contained primaquine 2.6 ng/mL), and carboxyprimaquine was likewise unmeasurable in the majority of infant samples (maximum value 25.8 ng/mL).,The estimated primaquine dose received by infants, based on measured breast milk levels, was 2.98 µg/kg/day (ie, ~0.6% of a hypothetical infant daily dose of 0.5 mg/kg).,There was no evidence of drug-related hemolysis in the infants.,Maternal levels were comparable to levels in nonlactating patients, and adverse events in mothers were mild.,The concentrations of primaquine in breast milk are very low and therefore very unlikely to cause adverse effects in the breastfeeding infant.,Primaquine should not be withheld from mothers breastfeeding infants or young children.,More information is needed in neonates.,NCT01780753.,Primaquine was excreted in very low levels in the breast milk of lactating women and caused no adverse effects in their infants.,Restrictions on primaquine use in mothers breastfeeding infants at least 28 days old should be lifted.

High-grade chloroquine (CQ)-resistant Plasmodium vivax is prevalent in eastern Malaysia.,Artesunate-mefloquine is an efficacious artemisinin combination therapy (ACT) for all malaria species.,Wider CQ-efficacy surveillance is needed in vivax-endemic regions with earlier replacement with ACT when treatment failure is detected.,Background.,Chloroquine (CQ)-resistant Plasmodium vivax is increasingly reported throughout southeast Asia.,The efficacy of CQ and alternative artemisinin combination therapies (ACTs) for vivax malaria in Malaysia is unknown.,Methods.,A randomized, controlled trial of CQ vs artesunate-mefloquine (AS-MQ) for uncomplicated vivax malaria was conducted in 3 district hospitals in Sabah, Malaysia.,Primaquine was administered on day 28.,The primary outcome was the cumulative risk of treatment failure by day 28 by Kaplan-Meier analysis.,Results.,From 2012 to 2014, 103 adults and children were enrolled.,Treatment failure by day 28 was 61.1% (95% confidence interval [CI], 46.8-75.6) after CQ and 0% (95% CI, 0-.08) following AS-MQ (P < .001), of which 8.2% (95% CI, 2.5-9.6) were early treatment failures.,All patients with treatment failure had therapeutic plasma CQ concentrations at day 7.,Compared with CQ, AS-MQ was associated with faster parasite clearance (normalized clearance slope, 0.311 vs 0.127; P < .001) and fever clearance (mean, 19.0 vs 37.7 hours; P = .001) and with lower risk of anemia at day 28 (odds ratio = 3.7; 95% CI, 1.5-9.3; P = .005).,Gametocytes were present at day 28 in 23.8% (10/42) of patients following CQ vs none with AS-MQ (P < .001).,AS-MQ resulted in lower bed occupancy: 4037 vs 6510 days/1000 patients (incidence rate ratio 0.62; 95% CI, .60-.65; P < .001).,One patient developed severe anemia not regarded as related to their AS-MQ treatment.,Conclusions.,High-grade CQ-resistant P. vivax is prevalent in eastern Malaysia.,AS-MQ is an efficacious ACT for all malaria species.,Wider CQ-efficacy surveillance is needed in vivax-endemic regions with earlier replacement with ACT when treatment failure is detected.,Clinical Trials Registration.,NCT01708876.

Due to outdoor and residual transmission and insecticide resistance, long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS) will be insufficient as stand-alone malaria vector control interventions in many settings as programmes shift toward malaria elimination.,Combining additional vector control interventions as part of an integrated strategy would potentially overcome these challenges.,Larval source management (LSM) and structural house improvements (HI) are appealing as additional components of an integrated vector management plan because of their long histories of use, evidence on effectiveness in appropriate settings, and unique modes of action compared to LLINs and IRS.,Implementation of LSM and HI through a community-based approach could provide a path for rolling-out these interventions sustainably and on a large scale.,We will implement community-based LSM and HI, as additional interventions to the current national malaria control strategies, using a randomised block, 2 × 2 factorial, cluster-randomised design in rural, southern Malawi.,These interventions will be continued for two years.,The trial catchment area covers about 25,000 people living in 65 villages.,Community participation is encouraged by training community volunteers as health animators, and supporting the organisation of village-level committees in collaboration with The Hunger Project, a non-governmental organisation.,Household-level cross-sectional surveys, including parasitological and entomological sampling, will be conducted on a rolling, 2-monthly schedule to measure outcomes over two years (2016 to 2018).,Coverage of LSM and HI will also be assessed throughout the trial area.,Combining LSM and/or HI together with the interventions currently implemented by the Malawi National Malaria Control Programme is anticipated to reduce malaria transmission below the level reached by current interventions alone.,Implementation of LSM and HI through a community-based approach provides an opportunity for optimum adaptation to the local ecological and social setting, and enhances the potential for sustainability.,Registered with The Pan African Clinical Trials Registry on 3 March 2016, trial number PACTR201604001501493.,The online version of this article (10.1186/s12879-017-2749-2) contains supplementary material, which is available to authorized users.

Malaria is endemic throughout Malawi, but little is known about quality of malaria case management at publicly-funded health facilities, which are the major source of care for febrile patients.,In April-May 2011, we conducted a nationwide, geographically-stratified health facility survey to assess the quality of outpatient malaria diagnosis and treatment.,We enrolled patients presenting for care and conducted exit interviews and re-examinations, including reference blood smears.,Moreover, we assessed health worker readiness (e.g., training, supervision) and health facility capacity (e.g. availability of diagnostics and antimalarials) to provide malaria case management.,All analyses accounted for clustering and unequal selection probabilities.,We also used survey weights to produce estimates of national caseloads.,At the 107 facilities surveyed, most of the 136 health workers interviewed (83%) had received training on malaria case management.,However, only 24% of facilities had functional microscopy, 15% lacked a thermometer, and 19% did not have the first-line artemisinin-based combination therapy (ACT), artemether-lumefantrine, in stock.,Of 2,019 participating patients, 34% had clinical malaria (measured fever or self-reported history of fever plus a positive reference blood smear).,Only 67% (95% confidence interval (CI): 59%, 76%) of patients with malaria were correctly prescribed an ACT, primarily due to missed malaria diagnosis.,Among patients without clinical malaria, 31% (95% CI: 24%, 39%) were prescribed an ACT.,By our estimates, 1.5 million of the 4.4 million malaria patients seen in public facilities annually did not receive correct treatment, and 2.7 million patients without clinical malaria were inappropriately given an ACT.,Malawi has a high burden of uncomplicated malaria but nearly one-third of all patients receive incorrect malaria treatment, including under- and over-treatment.,To improve malaria case management, facilities must at minimum have basic case management tools, and health worker performance in diagnosing malaria must be improved.

Planning and evaluating malaria control strategies relies on accurate definition of parasite prevalence in the population.,A large proportion of asymptomatic parasite infections can only be identified by surveillance with molecular methods, yet these infections also contribute to onward transmission to mosquitoes.,The sensitivity of molecular detection by PCR is limited by the abundance of the target sequence in a DNA sample; thus, detection becomes imperfect at low densities.,We aimed to increase PCR diagnostic sensitivity by targeting multi-copy genomic sequences for reliable detection of low-density infections, and investigated the impact of these PCR assays on community prevalence data.,Two quantitative PCR (qPCR) assays were developed for ultra-sensitive detection of Plasmodium falciparum, targeting the high-copy telomere-associated repetitive element 2 (TARE-2, ∼250 copies/genome) and the var gene acidic terminal sequence (varATS, 59 copies/genome).,Our assays reached a limit of detection of 0.03 to 0.15 parasites/μl blood and were 10× more sensitive than standard 18S rRNA qPCR.,In a population cross-sectional study in Tanzania, 295/498 samples tested positive using ultra-sensitive assays.,Light microscopy missed 169 infections (57%).,18S rRNA qPCR failed to identify 48 infections (16%), of which 40% carried gametocytes detected by pfs25 quantitative reverse-transcription PCR.,To judge the suitability of the TARE-2 and varATS assays for high-throughput screens, their performance was tested on sample pools.,Both ultra-sensitive assays correctly detected all pools containing one low-density P. falciparum-positive sample, which went undetected by 18S rRNA qPCR, among nine negatives.,TARE-2 and varATS qPCRs improve estimates of prevalence rates, yet other infections might still remain undetected when absent in the limited blood volume sampled.,Measured malaria prevalence in communities is largely determined by the sensitivity of the diagnostic tool used.,Even when applying standard molecular diagnostics, prevalence in our study population was underestimated by 8% compared to the new assays.,Our findings highlight the need for highly sensitive tools such as TARE-2 and varATS qPCR in community surveillance and for monitoring interventions to better describe malaria epidemiology and inform malaria elimination efforts.,Ingrid Felger and colleagues developed an assay that targets multi-copy genomic sequences and can detect low-density infections with falciparum malaria parasites.,Nearly half the world's population is at risk of malaria, and more than 600,000 people die from this mosquito-borne parasitic infection every year.,Most of these deaths are caused by Plasmodium falciparum, which is transmitted to people by night-flying Anopheles mosquitoes.,These insects inject “sporozoites” into people, a parasitic form that replicates inside human liver cells.,After a few days, the liver cells release “merozoites,” which invade red blood cells, where they replicate rapidly before bursting out and infecting more red blood cells.,This increase in parasitic burden causes malaria's characteristic fever, which needs to be treated promptly to prevent anemia and organ damage.,Infected red blood cells also release “gametocytes,” which infect mosquitoes when they take a blood meal.,In the mosquito, the gametocytes multiply and develop into sporozoites, thus completing the parasite's life cycle.,Malaria can be prevented by controlling the mosquitoes that spread the parasite and by avoiding mosquito bites.,Effective treatment with antimalarial drugs also helps to reduce malaria transmission and is a key component of global efforts to control and eliminate malaria.,Planning and evaluating malaria control and elimination efforts relies on having accurate and sensitive methods to measure parasite prevalence-the proportion of a population infected with parasites.,It is particularly important to know how many people are carrying low-density infections because although these individuals have no symptoms, they contribute to malaria transmission.,In the past, malaria was usually diagnosed by looking for parasites in blood using light microscopy, but molecular tests based on “quantitative polymerase chain reactions” (qPCRs) are now available that detect much lower parasite densities in blood (submicroscopic infections). qPCRs detect parasite-specific DNA sequences in patient blood samples, but reliable detection of low-density infections remains imperfect because the abundance of target sequences in patient samples limits the sensitivity of current qPCR methods.,Here, the researchers investigate whether the sensitivity of P. falciparum detection using qPCR can be improved by targeting multi-copy genomic sequences-DNA sequences that are repeated many times in the parasite's genetic blueprint.,The researchers developed two new qPCRs for P. falciparum by using the telomere-associated repetitive element 2 (TARE-2; 250 copies/genome) and the var gene acidic terminal sequence (varATS; 59 copies/genome) as target sequences.,Direct comparison of these qPCRs with the standard 18S rRNA qPCR for P. falciparum, which targets a gene present at 5-8 copies/genome, indicated that the new assays were ten times more sensitive than the standard assay and could detect as few as 0.03-0.15 parasites/μl blood.,Next, the researchers used light microscopy, 18S rRNA qPCR, and the two new qPCRs to look for P. falciparum parasites in 498 samples randomly selected from a malaria survey undertaken in Tanzania.,Parasite prevalences were 25% by light microscopy, 50% by 18S rRNA qPCR, and 58% by TARE-2 or varATS qPCR.,Compared to TARE-2 or varATS qPCR, 18S rRNA qPCR failed to identify 48 infections (16% of infections).,Moreover, 40% of the positive samples missed by 18S rRNA qPCR contained gametocytes (detected by a different PCR-based assay) and therefore came from individuals capable of transmitting malaria parasites to mosquitoes.,Finally, to test the suitability of the new ultra-sensitive assays for use in high-throughput screens, the researchers tested performance of the assays on sample pools.,Both tests correctly identified all pools containing one low-density P. falciparum-positive sample among nine negative samples, whereas 18S rRNA qPCR identified none of these pools.,These findings provide evidence of low-density malaria infections in individuals previously thought to be parasite-free, even after testing with a molecular diagnostic.,Notably, in the population considered in this study, the standard 18S rRNA qPCR underestimated parasite prevalence by nearly 10%.,The assays developed in this study have some important limitations, however.,First, they detect only P. falciparum, and malaria control programs ideally need assays that detect all the Plasmodium species that cause malaria.,Second, because the TARE-2 and varATS qPCRs require advanced laboratory infrastructure, they cannot be used in remote field settings.,Nevertheless, because low-density infections are likely to become increasingly common as countries improve malaria control, these findings highlight the need for ultra-sensitive tools such as the TARE-2 and varATS qPCRs for community surveillance and for monitoring the progress of malaria control and elimination programs.,Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001788.,Information is available from the World Health Organization on malaria (in several languages), including information on malaria diagnosis; the World Malaria Report 2014 provides details of the current global malaria situation,The US Centers for Disease Control and Prevention also provides information on all aspects of malaria; its website provides a selection of personal stories about malaria,Information is available from the Roll Back Malaria Partnership on the global control of malaria and on the Global Malaria Action Plan (in English and French),MedlinePlus provides links to additional information on malaria (in English and Spanish)

The haemozoin crystal continues to be investigated extensively for its potential as a biomarker for malaria diagnostics.,In order for haemozoin to be a valuable biomarker, it must be present in detectable quantities in the peripheral blood and distinguishable from false positives.,Here, dark-field microscopy coupled with sophisticated image processing algorithms is used to characterize the abundance of detectable haemozoin within infected erythrocytes from field samples in order to determine the window of detection in peripheral blood.,Thin smears from Plasmodium falciparum-infected and uninfected patients were imaged in both dark field (DF) unstained and bright field (BF) Giemsa-stained modes.,The images were co-registered such that each parasite had thumbnails in both BF and DF modes, providing an accurate map between parasites and DF objects.,This map was used to find the abundance of haemozoin as a function of parasite stage through careful parasite staging and correlation with DF objects.,An automated image-processing and classification algorithm classified the bright spots in the DF images as either haemozoin or non-haemozoin objects.,The algorithm distinguishes haemozoin from non-haemozoin objects in DF images with an object-level sensitivity of 95% and specificity of 97%.,Ring stages older than about 6 hours begin to show detectable haemozoin, and rings between 10-16 hours reliably contain detectable haemozoin.,However, DF microscopy coupled with the image-processing algorithm detect no haemozoin in rings younger than six hours.,Although this method demonstrates the most sensitive detection of haemozoin in field samples reported to date, it does not detect haemozoin in ring-stage parasites younger than six hours.,Thus, haemozoin is a poor biomarker for field samples primarily composed of young ring-stage parasites because the crystal is not present in detectable quantities by the methods described here.,Based on these results, the implications for patient-level diagnosis and recommendations for future work are discussed.

We earlier established that nitric oxide (NO) is protective against severe malaria and that arginine and NO levels are reduced in malaria patients.,We now show that an M2-like blood monocyte phenotype is significantly associated with hypoargininemia, NO insufficiency, and disease severity in Tanzanian children with falciparum malaria.,Compared to control children (n = 106), children with moderately severe (n = 77) and severe falciparum malaria (n = 129) had significantly higher mononuclear cell arginase 1 mRNA, protein, and enzyme activity; lower NOS2 mRNA; lower plasma arginine; and higher plasma IL-10, IL-13, and IL-4.,In addition, monocyte CD206 and CD163 and plasma soluble CD163 were elevated.,Multivariate logistic regression analysis revealed a significant correlation of risk of severe malaria with both plasma IL-10 and soluble CD163 levels.,Monocyte M2 skewing likely contributes to NO bioinsufficiency in falciparum malaria in children.,Treatments that reverse the M2 polarization may have potential as adjunctive treatment for malaria.

Quinine remains an important anti-malarial drug almost 400 years after its effectiveness was first documented.,However, its continued use is challenged by its poor tolerability, poor compliance with complex dosing regimens, and the availability of more efficacious anti-malarial drugs.,This article reviews the historical role of quinine, considers its current usage and provides insight into its appropriate future use in the treatment of malaria.,In light of recent research findings intravenous artesunate should be the first-line drug for severe malaria, with quinine as an alternative.,The role of rectal quinine as pre-referral treatment for severe malaria has not been fully explored, but it remains a promising intervention.,In pregnancy, quinine continues to play a critical role in the management of malaria, especially in the first trimester, and it will remain a mainstay of treatment until safer alternatives become available.,For uncomplicated malaria, artemisinin-based combination therapy (ACT) offers a better option than quinine though the difficulty of maintaining a steady supply of ACT in resource-limited settings renders the rapid withdrawal of quinine for uncomplicated malaria cases risky.,The best approach would be to identify solutions to ACT stock-outs, maintain quinine in case of ACT stock-outs, and evaluate strategies for improving quinine treatment outcomes by combining it with antibiotics.,In HIV and TB infected populations, concerns about potential interactions between quinine and antiretroviral and anti-tuberculosis drugs exist, and these will need further research and pharmacovigilance.

Nearly one million people are killed every year by the malaria parasite Plasmodium.,Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission.,Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host.,We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission.

A systematic review and meta-analysis examining the association between anti-merozoite antibody responses and incidence of Plasmodium falciparum malaria by Freya Fowkes and colleagues aids identification of antigens that confer protection from malaria.,One of the criteria to objectively prioritize merozoite antigens for malaria vaccine development is the demonstration that naturally acquired antibodies are associated with protection from malaria.,However, published evidence of the protective effect of these antibodies is conflicting.,We performed a systematic review with meta-analysis of prospective cohort studies examining the association between anti-merozoite immunoglobin (Ig) G responses and incidence of Plasmodium falciparum malaria.,Two independent researchers searched six databases and identified 33 studies that met predefined inclusion and quality criteria, including a rigorous definition of symptomatic malaria.,We found that only five studies were performed outside sub-Saharan Africa and that there was a deficiency in studies investigating antibodies to leading vaccine candidates merozoite surface protein (MSP)-142 and erythrocyte binding antigen (EBA)-175.,Meta-analyses of most-studied antigens were conducted to obtain summary estimates of the association between antibodies and incidence of P. falciparum malaria.,The largest effect was observed with IgG to MSP-3 C terminus and MSP-119 (responders versus nonresponders, 54%, 95% confidence interval [CI] [33%-68%] and 18% [4%-30%] relative reduction in risk, respectively) and there was evidence of a dose-response relationship.,A tendency towards protective risk ratios (RR<1) was also observed for individual study estimates for apical membrane antigen (AMA)-1 and glutamate-rich protein (GLURP)-R0.,Pooled estimates showed limited evidence of a protective effect for antibodies to MSP-1 N-terminal regions or MSP-1-EGF (epidermal growth factor-like modules).,There was no significant evidence for the protective effect for MSP-2 (responders versus nonresponders pooled RR, MSP-2FC27 0.82, 95% CI 0.62-1.08, p = 0.16 and MSP-23D7 0.92, 95% CI 0.75-1.13, p = 0.43).,Heterogeneity, in terms of clinical and methodological diversity between studies, was an important issue in the meta-analysis of IgG responses to merozoite antigens.,These findings are valuable for advancing vaccine development by providing evidence supporting merozoite antigens as targets of protective immunity in humans, and to help identify antigens that confer protection from malaria.,Further prospective cohort studies that include a larger number of lead antigens and populations outside Africa are greatly needed to ensure generalizability of results.,The reporting of results needs to be standardized to maximize comparability of studies.,We therefore propose a set of guidelines to facilitate the uniform reporting of malaria immuno-epidemiology observational studies.,Please see later in the article for the Editors' Summary,Plasmodium falciparum malaria, a mosquito-borne parasitic infection, kills about one million people every year.,Around a week after an infected mosquito has bitten a person, “merozoites” (one of the life-stages of the parasite) infect the person's red blood cells where they replicate and then burst out and infect more red blood cells.,Rapid replication of parasites can occur in the bloodstream, leading to massive numbers of parasites that can damage vital organs.,Although individuals can lower their risk of becoming infected with malaria parasites by avoiding mosquito bites, a vaccine is urgently needed to reduce the global burden of malaria.,When malaria parasites infect a person for the first time, the human immune system begins to produce antibodies, proteins that recognize molecules (antigens) on the parasite's surface and that act directly or cooperate with other parts of the immune system to kill malaria parasites.,The production of these “naturally acquired” antibodies is initially slow so the individual can become ill when infected.,However, because the immune system “remembers” how to make the antibodies, its response to subsequent infections is quicker.,The levels of these antibodies also build up with each infection and become more effective at killing parasites.,Vaccines, which contain malaria antigens, “prime” the immune system to respond rapidly to malaria infections and produce high concentrations of antibodies to prevent the infection from causing serious illness.,A malaria vaccine that stimulates an efficient immune response against merozoites would limit the severity of malarial infections and prevent many deaths but no one knows which (if any) of the antigens on merozoites stimulate a protective immune response.,Although many different types of antibodies are produced by the immune system, only some of these are effective in protecting against malaria.,By investigating whether there is an association between naturally acquired antibodies, which recognize specific candidate antigens, and protection from malaria in populations living in areas where malaria is endemic (always present), vaccine developers can get an idea about which antigens to include in their vaccines.,Although many of these “malaria immuno-epidemiological studies” have been undertaken, their results are somewhat conflicting.,In this study, the researchers reanalyze these results by doing a systematic review (a study that uses predefined criteria to identify all the research on a specific topic) and a meta-analysis (a statistical method for combining the results of several studies).,The researchers evaluated studies of the relationship between anti-merozoite antibodies and the incidence (the number of new cases of a disease in a population per year) of P. falciparum malaria in naturally exposed populations in different regions of the world.,The researchers' search of the published literature yielded 33 studies in which the incidence of malaria had been recorded over time in groups of people in whom levels of antibodies to specific merozoite antigens had been measured.,These studies measured antibodies at the start of the study and examined the subsequent risk of malaria over several months of follow-up (these are known as prospective cohort studies).,All but five of the studies were performed in Africa, and very few merozoite antigens had been well-studied in different populations, or studied at all.,Of note, very few studies had examined naturally acquired antibodies to some leading vaccine candidates (for example, only one study considered antibodies to MSP-142, a leading vaccine candidate).,Conversely, the association between malaria incidence and antibodies to the antigen MSP-119, which has been included in only one candidate vaccine, was frequently studied.,In their meta-analyses, the researchers found that among people with antibodies to the merozoite antigens MSP-3 (C-terminal region) and MSP-119, the risk of developing P. falciparum malaria was reduced by 54% and 18%, respectively, compared to people without antibodies to these antigens.,There was also some evidence of a reduced risk of malaria for people with antibodies to AMA1 and GLURP.,For other merozoite antigens, MSP1 (N-terminal region) and MSP2, there was either weak or no evidence for a protective effect of naturally acquired antibodies.,These findings suggest that merozoite antigens are important targets of protective immunity in people who are naturally exposed to malaria and also suggest which of these antigens might be included in vaccines.,However, the findings are limited by the small number of studies identified by the researchers and additional prospective cohort studies are clearly needed to guide vaccine development.,These studies will need to include a larger number of lead antigens and populations outside Africa to ensure their generalizability, note the researchers.,Furthermore, efforts will need to be made to ensure greater consistency between studies to improve the ability to compare results between different studies, which was a challenge in performing this study.,To this end, the researchers propose a set of guidelines that, if followed, should make it easier to compare the results of different malaria immune-epidemiology studies in the future and thus lead to better identification of candidate vaccine antigens.,Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000218.,Information is available from the World Health Organization on malaria (in several languages) and on the development of malaria vaccines,The US Centers for Disease Control and Prevention provides information on malaria (in English and Spanish),Information is available from the Wellcome Trust on all aspects of malaria, including vaccine development,The Malaria Vaccine Initiative provides information on the development of malaria vaccines and on ongoing trials,MedlinePlus provides links to additional information on malaria (in English and Spanish)

A major challenge in the control of human African trypanosomiasis (HAT) is lack of reliable diagnostic tests that are rapid and easy to use in remote areas where the disease occurs.,In Trypanosoma brucei gambiense HAT, the Card Agglutination Test for Trypanosomiasis (CATT) has been the reference screening test since 1978, usually on whole blood, but also in a 1/8 dilution (CATT 1/8) to enhance specificity.,However, the CATT is not available in a single format, requires a cold chain for storage, and uses equipment that requires electricity.,A solution to these challenges has been provided by rapid diagnostic tests (RDT), which have recently become available.,A prototype immunochromatographic test, the SD BIOLINE HAT, based on two native trypanosomal antigens (VSG LiTat 1.3 and VSG LiTat 1.5) has been developed.,We carried out a non-inferiority study comparing this prototype to the CATT 1/8 in field settings.,The prototype SD BIOLINE HAT, the CATT Whole Blood and CATT 1/8 were systematically applied on fresh blood samples obtained from 14,818 subjects, who were prospectively enrolled through active and passive screening in clinical studies in three endemic countries of central Africa: Angola, the Democratic Republic of the Congo and the Central African Republic.,One hundred and forty nine HAT cases were confirmed by parasitology.,The sensitivity and specificity of the prototype SD BIOLINE HAT was 89.26% (95% confidence interval (CI) = 83.27-93.28) and 94.58% (95% CI = 94.20-94.94) respectively.,The sensitivity and specificity of the CATT on whole blood were 93.96% (95% CI = 88.92-96.79) and 95.91% (95% CI = 95.58-96.22), and of the CATT 1/8 were 89.26% (95% CI = 83.27-93.28) and 98.88% (95% CI = 98.70-99.04) respectively.,After further optimization, the prototype SD BIOLINE HAT could become an alternative to current screening methods in primary healthcare settings in remote, resource-limited regions where HAT typically occurs.

Trypanosoma brucei is a eukaryotic pathogen which causes African trypanosomiasis.,It is notable for its variant surface glycoprotein (VSG) coat, which undergoes antigenic variation enabled by a large suite of VSG pseudogenes, allowing for persistent evasion of host adaptive immunity.,While Trypanosoma brucei rhodesiense (Tbr) and T. b gambiense (Tbg) are human infective, related T. b. brucei (Tbb) is cleared by human sera.,A single gene, the Serum Resistance Associated (SRA) gene, confers Tbr its human infectivity phenotype.,Potential genetic recombination of this gene between Tbr and non-human infective Tbb strains has significant epidemiological consequences for Human African Trypanosomiasis outbreaks.,Using long and short read whole genome sequencing, we generated a hybrid de novo assembly of a Tbr strain, producing 4,210 scaffolds totaling approximately 38.8 megabases, which comprise a significant proportion of the Tbr genome, and thus represents a valuable tool for a comparative genomics analyses among human and non-human infective T. brucei and future complete genome assembly.,We detected 5,970 putative genes, of which two, an alcohol oxidoreductase and a pentatricopeptide repeat-containing protein, were members of gene families common to all T. brucei subspecies, but variants specific to the Tbr strain sequenced in this study.,Our findings confirmed the extremely high level of genomic similarity between the two parasite subspecies found in other studies.,We confirm at the whole genome level high similarity between the two Tbb and Tbr strains studied.,The discovery of extremely minor genomic differentiation between Tbb and Tbr suggests that the transference of the SRA gene via genetic recombination could potentially result in novel human infective strains, thus all genetic backgrounds of T. brucei should be considered potentially human infective in regions where Tbr is prevalent.

The dynamics of Plasmodium vivax infection is characterized by reactivation of hypnozoites at varying time intervals.,The relative contribution of new P. vivax infection and reactivation of dormant liver stage hypnozoites to initiation of blood stage infection is unclear.,In this study, we investigate the contribution of new inoculations of P. vivax sporozoites to primary infection versus reactivation of hypnozoites by modeling the dynamics of P. vivax infection in Thailand in patients receiving treatment for either blood stage infection alone (chloroquine), or the blood and liver stages of infection (chloroquine + primaquine).,In addition, we also analysed rates of infection in a study in Papua New Guinea (PNG) where patients were treated with either artesunate, or artesunate + primaquine.,Our results show that up to 96% of the P. vivax infection is due to hypnozoite reactivation in individuals living in endemic areas in Thailand.,Similar analysis revealed the around 70% of infections in the PNG cohort were due to hypnozoite reactivation.,We show how the age of the cohort, primaquine drug failure, and seasonality may affect estimates of the ratio of primary P. vivax infection to hypnozoite reactivation.,Modeling of P. vivax primary infection and hypnozoite reactivation provides important insights into infection dynamics, and suggests that 90-96% of blood stage infections arise from hypnozoite reactivation.,Major differences in infection kinetics between Thailand and PNG suggest the likelihood of drug failure in PNG.

We sequenced and annotated the genomes of four Plasmodium vivax strains collected from disparate geographical locations, tripling the number of genome sequences available for this understudied parasite and providing the first genome-wide perspective of global variability within this species.,We observe approximately twice as much SNP diversity among these isolates as we do among a comparable collection of isolates of Plasmodium falciparum, a malaria parasite that causes higher mortality.,This indicates a distinct history of global colonization and/or a more stable demographic history for P. vivax than P. falciparum, which is thought to have undergone a recent population bottleneck.,The SNP diversity, as well as additional microsatellite and gene family variability, suggests the capacity for greater functional variation within the global population of P. vivax.,These findings warrant a deeper survey of variation in P. vivax to equip disease interventions targeting the distinctive biology of this neglected but major pathogen.

Cas9/gRNA-mediated gene-drive systems have advanced development of genetic technologies for controlling vector-borne pathogen transmission.,These technologies include population suppression approaches, genetic analogs of insecticidal techniques that reduce the number of insect vectors, and population modification (replacement/alteration) approaches, which interfere with competence to transmit pathogens.,Here, we develop a recoded gene-drive rescue system for population modification of the malaria vector, Anopheles stephensi, that relieves the load in females caused by integration of the drive into the kynurenine hydroxylase gene by rescuing its function.,Non-functional resistant alleles are eliminated via a dominantly-acting maternal effect combined with slower-acting standard negative selection, and rare functional resistant alleles do not prevent drive invasion.,Small cage trials show that single releases of gene-drive males robustly result in efficient population modification with ≥95% of mosquitoes carrying the drive within 5-11 generations over a range of initial release ratios.,Gene drives may be impeded by the generation of resistant alleles following NHEJ.,Here the authors develop a recoded gene-drive rescue system for the malaria mosquito, Anopheles stephensi, that targets the drive to the kynurenine hydroxylase gene for negative selection against mutated alleles.

It has been theorized that inducing extreme reproductive sex ratios could be a method to suppress or eliminate pest populations.,Limited knowledge about the genetic makeup and mode of action of naturally occurring sex distorters and the prevalence of co-evolving suppressors has hampered their use for control.,Here we generate a synthetic sex distortion system by exploiting the specificity of the homing endonuclease I-PpoI, which is able to selectively cleave ribosomal gene sequences of the malaria vector Anopheles gambiae that are located exclusively on the mosquito’s X chromosome.,We combine structure-based protein engineering and molecular genetics to restrict the activity of the potentially toxic endonuclease to spermatogenesis.,Shredding of the paternal X chromosome prevents it from being transmitted to the next generation, resulting in fully fertile mosquito strains that produce >95% male offspring.,We demonstrate that distorter male mosquitoes can efficiently suppress caged wild-type mosquito populations, providing the foundation for a new class of genetic vector control strategies.,Extreme reproductive sex ratios could result in the suppression or elimination of pest populations.,Here, the authors design a synthetic sex distortion system in Anopheles gambiae that gives rise to fertile mosquito strains that produce over 95% male offsprings and could therefore be used to suppress mosquito populations.

SSG&PM over 17 days is recommended as first line treatment for visceral leishmaniasis in eastern Africa, but is painful and requires hospitalization.,Combination regimens including AmBisome and miltefosine are safe and effective in India, but there are no published data from trials of combination therapies including these drugs from Africa.,A phase II open-label, non-comparative randomized trial was conducted in Sudan and Kenya to evaluate the efficacy and safety of three treatment regimens: 10 mg/kg single dose AmBisome plus 10 days of SSG (20 mg/kg/day), 10 mg/kg single dose AmBisome plus 10 days of miltefosine (2.5mg/kg/day) and miltefosine alone (2.5 mg/kg/day for 28 days).,The primary endpoint was initial parasitological cure at Day 28, and secondary endpoints included definitive cure at Day 210, and pharmacokinetic (miltefosine) and pharmacodynamic assessments.,In sequential analyses with 49-51 patients per arm, initial cure was 85% (95% CI: 73-92) in all arms.,At D210, definitive cure was 87% (95% CI: 77-97) for AmBisome + SSG, 77% (95% CI 64-90) for AmBisome + miltefosine and 72% (95% CI 60-85) for miltefosine alone, with lower efficacy in younger patients, who weigh less.,Miltefosine pharmacokinetic data indicated under-exposure in children compared to adults.,No major safety concerns were identified, but point estimates of definitive cure were less than 90% for each regimen so none will be evaluated in Phase III trials in their current form.,Allometric dosing of miltefosine in children needs to be evaluated.,The study was registered with ClinicalTrials.gov, number NCT01067443

Visceral leishmaniasis (VL) is a neglected parasitic disease that is fatal if left untreated and is endemic in eastern Sudan.,We estimated the direct and indirect costs of treatment of VL from the perspective of the provider and the household at three public hospitals in Gedaref State.,The median total cost for one VL episode was estimated to be US$450.,Despite the free provision of VL drugs at public hospitals, households bore 53% of the total cost of VL with one episode of VL representing 40% of the annual household income.,More than 75% of households incurred catastrophic out-of-pocket expenditures.,The length of treatment of 30 days led to important costs for both health providers and households.,Alternative treatment regimens that reduce the duration of treatment are urgently needed.

An epidemiological and entomological study was carried out in Balaghat district, Madhya Pradesh, India to understand the dynamics of forest malaria transmission in a difficult and hard to reach area where indoor residual spray and insecticide treated nets were used for vector control.,This community based cross-sectional study was undertaken from January 2010 to December 2012 in Baihar and Birsa Community Health Centres of district Balaghat for screening malaria cases.,Entomological surveillance included indoor resting collections, pyrethrum spray catches and light trap catches.,Anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite protein.,Plasmodium falciparum infection accounted for >80% of all infections.,P. vivax 16.5%, P. malariae 0.75% and remaining were mixed infections of P. falciparum, P. vivax and P. malariae.,More than, 30% infections were found in infants under 6 months of age.,Overall, an increasing trend in malaria positivity was observed from 2010 to 2012 (chi-square for trend = 663.55; P<0.0001).,Twenty five Anopheles culicifacies (sibling species C, D and E) were positive for circumsporozoite protein of P. falciparum (44%) and P. vivax (56%).,Additionally, 2 An. fluviatilis, were found positive for P. falciparum and 1 for P. vivax (sibling species S and T).,An. fluviatilis sibling species T was found as vector in forest villages for the first time in India.,These results showed that the study villages are experiencing almost perennial malaria transmission inspite of indoor residual spray and insecticide treated nets.,Therefore, there is a need for new indoor residual insecticides which has longer residual life or complete coverage of population with long lasting insecticide treated nets or both indoor residual spray and long lasting bed nets for effective vector control.,There is a need to undertake a well designed case control study to evaluate the efficacy of these interventions.

For many years social economic status has been used as an indicator to characterize malaria treatment seeking behaviors of communities and their adherence to malaria control programs.,The present study was therefore conducted to assess the influence of household social economic status, knowledge, attitude and practice on treatment seeking behaviors, distance to health facilities and vector control measures in the Lower Moshi area, northern Tanzania.,A cross-sectional household survey was carried out, a quantitative method was used to collect information from the households, and the household socio-economic status was estimated by employing a household asset-based approach.,The structured questionnaire also collected information on malaria knowledge, attitudes and treatment seeking behaviors.,A total of 197 (68.8% were female) household heads were interviewed.,Distance to the health centers influenced malaria treatment seeking behaviors especially for children (P = 0.001) and the number of visits to the health facilities made by the household members (P = 0.001).,The head of the households' level of education had an influence on bed-net retreatment (P < 0.001) and acceptability of larval control programmes (P <0.001).,Similarly, a significant association was observed between bed-net retreatment, larval control and occupation of the head of the household .,Distance to the health centre influenced malaria treatment seeking behaviors, and the number of visits made by the household members.,In addition, the education level of the household heads played a role in understanding and in the selection of malaria interventions for the households.,Increasing the number of health facilities close to rural areas will improve malaria treatment seeking behavior, case management and hence reduce malaria-associated morbidities, especially in high risk groups.

The widespread distribution and relapsing nature of Plasmodium vivax infection present major challenges for malaria elimination.,To characterise the genetic diversity of this parasite within individual infections and across the population, we performed deep genome sequencing of >200 clinical samples collected across the Asia-Pacific region, and analysed data on >300,000 SNPs and 9 regions of the genome with large copy number variations.,Individual infections showed complex patterns of genetic structure, with variation not only in the number of dominant clones but also in their level of relatedness and inbreeding.,At the population level, we observed strong signals of recent evolutionary selection both in known drug resistance genes and at novel loci, and these varied markedly between geographical locations.,These findings reveal a dynamic landscape of local evolutionary adaptation in P. vivax populations, and provide a foundation for genomic surveillance to guide effective strategies for control and elimination.

Solomon Islands is intensifying national efforts to achieve malaria elimination.,A long history of indoor spraying with residual insecticides, combined recently with distribution of long lasting insecticidal nets and artemether-lumefantrine therapy, has been implemented in Solomon Islands.,The impact of these interventions on local endemicity of Plasmodium spp. is unknown.,In 2012, a cross-sectional survey of 3501 residents of all ages was conducted in Ngella, Central Islands Province, Solomon Islands.,Prevalence of Plasmodium falciparum, P. vivax, P. ovale and P. malariae was assessed by quantitative PCR (qPCR) and light microscopy (LM).,Presence of gametocytes was determined by reverse transcription quantitative PCR (RT-qPCR).,By qPCR, 468 Plasmodium spp. infections were detected (prevalence = 13.4%; 463 P. vivax, five mixed P. falciparum/P. vivax, no P. ovale or P. malariae) versus 130 by LM (prevalence = 3.7%; 126 P. vivax, three P. falciparum and one P. falciparum/P. vivax).,The prevalence of P. vivax infection varied significantly among villages (range 3.0-38.5%, p<0.001) and across age groups (5.3-25.9%, p<0.001).,Of 468 P. vivax infections, 72.9% were sub-microscopic, 84.5% afebrile and 60.0% were both sub-microscopic and afebrile.,Local residency, low education level of the household head and living in a household with at least one other P. vivax infected individual increased the risk of P. vivax infection.,Overall, 23.5% of P. vivax infections had concurrent gametocytaemia.,Of all P. vivax positive samples, 29.2% were polyclonal by MS16 and msp1F3 genotyping.,All five P. falciparum infections were detected in residents of the same village, carried the same msp2 allele and four were positive for P. falciparum gametocytes.,P. vivax infection remains endemic in Ngella, with the majority of cases afebrile and below the detection limit of LM.,P. falciparum has nearly disappeared, but the risk of re-introductions and outbreaks due to travel to nearby islands with higher malaria endemicity remains.

Plasmodium vivax is a major cause of febrile illness in endemic areas of Asia, Central and South America, and the horn of Africa.,Plasmodium vivax infections are characterized by relapses of malaria arising from persistent liver stages of the parasite (hypnozoites) which can be prevented only by 8-aminoquinoline anti-malarials.,Tropical P. vivax relapses at three week intervals if rapidly eliminated anti-malarials are given for treatment, whereas in temperate regions and parts of the sub-tropics P. vivax infections are characterized either by a long incubation or a long-latency period between illness and relapse - in both cases approximating 8-10 months.,The epidemiology of the different relapse phenotypes has not been defined adequately despite obvious relevance to malaria control and elimination.,The number of sporozoites inoculated by the anopheline mosquito is an important determinant of both the timing and the number of relapses.,The intervals between relapses display a remarkable periodicity which has not been explained.,Evidence is presented that the proportion of patients who have successive relapses is relatively constant and that the factor which activates hypnozoites and leads to regular interval relapse in vivax malaria is the systemic febrile illness itself.,It is proposed that in endemic areas a large proportion of the population harbours latent hypnozoites which can be activated by a systemic illness such as vivax or falciparum malaria.,This explains the high rates of vivax following falciparum malaria, the high proportion of heterologous genotypes in relapses, the higher rates of relapse in people living in endemic areas compared with artificial infection studies, and, by facilitating recombination between different genotypes, contributes to P. vivax genetic diversity particularly in low transmission settings.,Long-latency P. vivax phenotypes may be more widespread and more prevalent than currently thought.,These observations have important implications for the assessment of radical treatment efficacy and for malaria control and elimination.

Accurate diagnosis of Plasmodium infections is essential for malaria morbidity and mortality reduction in tropical areas.,Despite great advantages of light microscopy (LM) for malaria diagnosis, its limited sensitivity is a critical shortfall for epidemiological studies.,Robust molecular diagnostics tools are thus needed.,The present study describes the development of a duplex quantitative real time PCR (qPCR) assay, which specifically detects and quantifies the four human Plasmodium species.,Performance of this method was compared to PCR-ligase detection reaction-fluorescent microsphere assay (PCR_LDR_FMA), nested PCR (nPCR) and LM, using field samples collected from 452 children one to five years of age from the Sepik area in Papua New Guinea.,Agreement between diagnostic methods was calcualted using kappa statistics.,The agreement of qPCR with other molecular diagnostic methods was substantial for the detection of P. falciparum, but was moderate for the detection of P. vivax, P. malariae and P. ovale.,P. falciparum and P. vivax prevalence by qPCR was 40.9% and 65.7% respectively.,This compares to 43.8% and 73.2% by nPCR and 47.1% and 67.5% by PCR_LDR_FMA.,P. malariae and P. ovale prevalence was 4.7% and 7.3% by qPCR, 3.3% and 3.8% by nPCR, and 7.7% and 4.4% by PCR_LDR_FMA.,Prevalence by LM was lower for all four species, being 25.4% for P. falciparum, 54.9% for P. vivax, 2.4% for P. malariae and 0.0% for P. ovale.,The quantification by qPCR closely correlated with microscopic quantification for P. falciparum and P. vivax samples (R2 = 0.825 and R2 = 0.505, respectively).,The low prevalence of P. malariae and P. ovale did not permit a solid comparative analysis of quantification for these species.,The qPCR assay developed proved optimal for detection of all four Plasmodium species.,Densities by LM were well reflected in quantification results by qPCR, whereby congruence was better for P. falciparum than for P. vivax.,This likely is a consequence of the generally lower P. vivax densities.,Easy performance of the qPCR assay, a less laborious workflow and reduced risk of contamination, together with reduced costs per sample through reduced reaction volume, opens the possibility to implement qPCR in endemic settings as a suitable diagnostic tool for large epidemiological studies.

Visceral Leishmaniasis (VL) due to Leishmania donovani is a neglected protozoan parasitic disease in humans, which is usually fatal if untreated.,Phlebotomus orientalis, the predominant VL vector in East Africa, is a highly exophilic/exophagic species that poses a major challenge to current Integrated Vector Management (IVM).,Here we report results of pilot studies conducted in rural villages in Gedarif state, Sudan, to evaluate outdoor residual spraying of 20mg active ingredient (a.i.) /m2 deltamethrin insecticide applied to the characteristic household compound boundary reed fence and to the outside of household buildings (Outdoor Residual Insecticide Spraying, ODRS), and as an alternative, spraying restricted to the boundary fence only (Restricted Outdoor Residual Insecticide Spraying, RODRS).,Four to six clusters of 20 households were assigned to insecticide treatments or control in three experiments.,Changes in sand fly numbers were monitored over 2,033 trap-nights over 43-76 days follow-up in four sentinel houses per cluster relative to unsprayed control clusters.,Sand fly numbers were monitored by sticky traps placed on the ground on the inside (“outdoor”) and the outside (“peridomestic”) of the boundary fence, and by CDC light traps suspended outdoors in the household compound.,The effects of ODRS on sand fly numbers inside sleeping huts were monitored by insecticide knockdown.,After a single application, ODRS reduced P. orientalis abundance by 83%-99% in outdoor and peridomestic trap locations.,ODRS also reduced numbers of P. orientalis found resting inside sleeping huts.,RODRS reduced outdoor and peridomestic P. orientalis by 60%-88%.,By direct comparison, RODRS was 58%-100% as effective as ODRS depending on the trapping method.,These impacts were immediate on intervention and persisted during follow-up, representing a large fraction of the P. orientalis activity season.,Relative costs of ODRS and RODRS delivery were $5.76 and $3.48 per household, respectively.,The study demonstrates the feasibility and high entomological efficacy of ODRS and RODRS, and the expected low costs relative to current IVM practises.,These methods represent novel sand fly vector control tools against predominantly exophilic/exophagic sand fly vectors, aimed to lower VL burdens in Sudan, with potential application in other endemic regions in East Africa.

Clustering commonly affects the uncertainty of parameter estimates in epidemiological studies.,Cluster-robust variance estimates (CRVE) are used to construct confidence intervals that account for single-level clustering, and are easily implemented in standard software.,When data are clustered at more than one level (e.g. village and household) the level for the CRVE must be chosen.,CRVE are consistent when used at the higher level of clustering (village), but since there are fewer clusters at the higher level, and consistency is an asymptotic property, there may be circumstances under which coverage is better from lower- rather than higher-level CRVE.,Here we assess the relative importance of adjusting for clustering at the higher and lower level in a logistic regression model.,We performed a simulation study in which the coverage of 95 % confidence intervals was compared between adjustments at the higher and lower levels.,Confidence intervals adjusted for the higher level of clustering had coverage close to 95 %, even when there were few clusters, provided that the intra-cluster correlation of the predictor was less than 0.5 for models with a single predictor and less than 0.2 for models with multiple predictors.,When there are multiple levels of clustering it is generally preferable to use confidence intervals that account for the highest level of clustering.,This only fails if there are few clusters at this level and the intra-cluster correlation of the predictor is high.,The online version of this article (doi:10.1186/s12874-016-0127-1) contains supplementary material, which is available to authorized users.

Kondo Rural Health Centre recorded 27 malaria patients between the 27th of January 2019 and the 2nd of February 2019 against an epidemic threshold of 19 with the malaria outbreak being confirmed on the 5th of February 2019.,Indoor residual spraying as part of integrated vector management control activities had been done in the district before the onset of the rainy season as well as social behaviour change communication but residents were contracting malaria.,We, therefore, investigated the risk factors associated with this outbreak to recommend scientifically effective prevention and control measures.,We conducted a 1:1 unmatched case-control study.,A case was a resident of Mudzi from the 4th of February 2019 who had a positive rapid diagnostic test for malaria randomly selected from the clinic’s line list whilst controls were randomly selected from the neighbourhood of cases.,Pretested interviewer-administered questionnaires were used to collect information on demographic characteristics, knowledge and practices of residents in malaria prevention.,Data were analysed using Epi info 7.,A total of 567 confirmed malaria cases was recorded with an overall attack rate of 71.7 per 1000 population.,Sixty-three case-control pairs were interviewed.,The majority of cases 78% (49/63) were from Makaza, Chanetsa and Nyarongo villages which are within 3 km from Vhombodzi dam.,A stagnant water body near a house [aOR = 8.0, 95%CI = (2.3-28.6)], engaging in outdoor activities before dawn or after dusk [aOR = 8.3, 95%CI = (1.1-62.7)] and having a house with open eaves [aOR = 5.4, 95%CI = (1.2-23.3)] were independent risk factors associated with contracting malaria.,Wearing long-sleeved clothes when outdoors at night [aOR = 0.2, 95%CI = (0.1-0.4)] was protective.,A stagnant water pool close to the homestead and engaging in outdoor activities before dawn and after dusk were modifiable risk factors associated with the malaria outbreak despite the community being knowledgeable on the transmission and prevention of malaria.,Community sensitisation and mobilisation in the destruction of stagnant water bodies and cutting of tall grass around homesteads were recommended measures to contain the outbreak.,The online version contains supplementary material available at 10.1186/s12889-020-09872-2.

The recently reported declining burden of malaria in some African countries has been attributed to scaling-up of different interventions although in some areas, these changes started before implementation of major interventions.,This study assessed the long-term trends of malaria burden for 20 years (1992-2012) in Magoda and for 15 years in Mpapayu village of Muheza district, north-eastern Tanzania, in relation to different interventions as well as changing national malaria control policies.,Repeated cross-sectional surveys recruited individuals aged 0 - 19 years from the two villages whereby blood smears were collected for detection of malaria parasites by microscopy.,Prevalence of Plasmodium falciparum infections and other indices of malaria burden (prevalence of anaemia, splenomegaly and gametocytes) were compared across the years and between the study villages.,Major interventions deployed including a mobile clinic, bed nets and other research activities, and changes in national malaria control policies were also marked.,In Magoda, the prevalence of P. falciparum infections initially decreased between 1992 and 1996 (from 83.5 to 62.0%), stabilized between 1996 and 1997, and further declined to 34.4% in 2004.,A temporary increase between 2004 and 2008 was followed by a progressive decline to 7.2% in 2012, which is more than 10-fold decrease since 1992.,In Mpapayu (from 1998), the highest prevalence was 81.5% in 1999 and it decreased to 25% in 2004.,After a slight increase in 2008, a steady decline followed, reaching <5% from 2011 onwards.,Bed net usage was high in both villages from 1999 to 2004 (≥88%) but it decreased between 2008 and 2012 (range, 28% - 68%).,After adjusting for the effects of bed nets, age, fever and year of study, the risk of P. falciparum infections decreased significantly by ≥97% in both villages between 1999 and 2012 (p < 0.001).,The prevalence of splenomegaly (>40% to <1%) and gametocytes (23% to <1%) also decreased in both villages.,A remarkable decline in the burden of malaria occurred between 1992 and 2012 and the initial decline (1992 - 2004) was most likely due to deployment of interventions, such as bed nets, and better services through research activities.,Apart from changes of drug policies, the steady decline observed from 2008 occurred when bed net coverage was low suggesting that other factors contributed to the most recent pattern.,These results suggest that continued monitoring is required to determine causes of the changing malaria epidemiology and also to monitor the progress towards maintaining low malaria transmission and reaching related millennium development goals.

Vector-borne diseases represent a major public health concern in most tropical and subtropical areas, and an emerging threat for more developed countries.,Our understanding of the ecology, evolution and control of these diseases relies predominantly on theory and data on pathogen transmission in large self-sustaining ‘source’ populations of vectors representative of highly endemic areas.,However, there are numerous places where environmental conditions are less favourable to vector populations, but where immigration allows them to persist.,We built an epidemiological model to investigate the dynamics of six major human vector borne-diseases in such non self-sustaining ‘sink’ vector populations.,The model was parameterized through a review of the literature, and we performed extensive sensitivity analysis to look at the emergence and prevalence of the pathogen that could be encountered in these populations.,Despite the low vector abundance in typical sink populations, all six human diseases were able to spread in 15-55% of cases after accidental introduction.,The rate of spread was much more strongly influenced by vector longevity, immigration and feeding rates, than by transmission and virulence of the pathogen.,Prevalence in humans remained lower than 5% for dengue, leishmaniasis and Japanese encephalitis, but substantially higher for diseases with longer duration of infection; malaria and the American and African trypanosomiasis.,Vector-related parameters were again the key factors, although their influence was lower than on pathogen emergence.,Our results emphasize the need for ecology and evolution to be thought in the context of metapopulations made of a mosaic of sink and source habitats, and to design vector control program not only targeting areas of high vector density, but working at a larger spatial scale.

In sub-Saharan Africa (SSA), malaria caused by Plasmodium falciparum has historically been a major contributor to morbidity and mortality.,Recent reports indicate a pronounced decline in infection and disease rates which are commonly ascribed to large-scale bed net programmes and improved case management.,However, the decline has also occurred in areas with limited or no intervention.,The present study assessed temporal changes in Anopheline populations in two highly malaria-endemic communities of NE Tanzania during the period 1998-2009.,Between 1998 and 2001 (1st period) and between 2003 and 2009 (2nd period), mosquitoes were collected weekly in 50 households using CDC light traps.,Data on rainfall were obtained from the nearby climate station and were used to analyze the association between monthly rainfall and malaria mosquito populations.,The average number of Anopheles gambiae and Anopheles funestus per trap decreased by 76.8% and 55.3%, respectively over the 1st period, and by 99.7% and 99.8% over the 2nd period.,During the last year of sampling (2009), the use of 2368 traps produced a total of only 14 Anopheline mosquitoes.,With the exception of the decline in An. gambiae during the 1st period, the results did not reveal any statistical association between mean trend in monthly rainfall and declining malaria vector populations.,A longitudinal decline in the density of malaria mosquito vectors was seen during both study periods despite the absence of organized vector control.,Part of the decline could be associated with changes in the pattern of monthly rainfall, but other factors may also contribute to the dramatic downward trend.,A similar decline in malaria vector densities could contribute to the decrease in levels of malaria infection reported from many parts of SSA.

A majority of emerging infectious diseases in humans are transmitted from animals.,It is generally agreed that our behavior can influence our exposure to such pathogens, but little is known regarding our role in shaping evolution in such pathogens.,Such understanding would aid in their control, to the benefit of public health.,Our results indicate that expansion of agriculture influenced not only the biogeography but also the virulence of Toxoplasma gondii.,By linking landscape ecology to parasite virulence, our framework contributes a fundamentally unique perspective on the ecology and evolution of infectious disease.,A majority of emerging infectious diseases in humans are zoonoses.,Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control.,Toxoplasma gondii is one of the most widespread zoonotic pathogens known today.,Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America.,Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere.,However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii.,Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii.,Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain.,Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading.,These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.

Trypanosoma brucei is an extracellular parasite that causes sleeping sickness.,In mammalian hosts, trypanosomes are thought to exist in two major niches: early in infection, they populate the blood; later, they breach the blood-brain barrier.,Working with a well-established mouse model, we discovered that adipose tissue constitutes a third major reservoir for T. brucei.,Parasites from adipose tissue, here termed adipose tissue forms (ATFs), can replicate and were capable of infecting a naive animal.,ATFs were transcriptionally distinct from bloodstream forms, and the genes upregulated included putative fatty acid β-oxidation enzymes.,Consistent with this, ATFs were able to utilize exogenous myristate and form β-oxidation intermediates, suggesting that ATF parasites can use fatty acids as an external carbon source.,These findings identify the adipose tissue as a niche for T. brucei during its mammalian life cycle and could potentially explain the weight loss associated with sleeping sickness.,•T. brucei parasites accumulate in the adipose tissue early after mouse infection•Adipose tissue forms (ATFs) can replicate and are capable of infecting naive mice•ATFs are transcriptionally distinct and upregulate genes for fatty acid metabolism•ATFs can actively uptake exogenous myristate and form β-oxidation intermediates,T. brucei parasites accumulate in the adipose tissue early after mouse infection,Adipose tissue forms (ATFs) can replicate and are capable of infecting naive mice,ATFs are transcriptionally distinct and upregulate genes for fatty acid metabolism,ATFs can actively uptake exogenous myristate and form β-oxidation intermediates,Trypanosoma brucei is found in the bloodstream and interstitial compartment of several organs in the mammalian host.,Trindade et al. uncover the adipose tissue as a major extravascular parasite niche.,Extensive remodeling of parasite gene expression in this lipid-rich environment includes upregulation of fatty acid β-oxidation enzymes, suggestive of a functional adaptation.

Although asexual reproduction via clonal propagation has been proposed as the principal reproductive mechanism across parasitic protozoa of the Leishmania genus, sexual recombination has long been suspected, based on hybrid marker profiles detected in field isolates from different geographical locations.,The recent experimental demonstration of a sexual cycle in Leishmania within sand flies has confirmed the occurrence of hybridisation, but knowledge of the parasite life cycle in the wild still remains limited.,Here, we use whole genome sequencing to investigate the frequency of sexual reproduction in Leishmania, by sequencing the genomes of 11 Leishmania infantum isolates from sand flies and 1 patient isolate in a focus of cutaneous leishmaniasis in the Çukurova province of southeast Turkey.,This is the first genome-wide examination of a vector-isolated population of Leishmania parasites.,A genome-wide pattern of patchy heterozygosity and SNP density was observed both within individual strains and across the whole group.,Comparisons with other Leishmania donovani complex genome sequences suggest that these isolates are derived from a single cross of two diverse strains with subsequent recombination within the population.,This interpretation is supported by a statistical model of the genomic variability for each strain compared to the L. infantum reference genome strain as well as genome-wide scans for recombination within the population.,Further analysis of these heterozygous blocks indicates that the two parents were phylogenetically distinct.,Patterns of linkage disequilibrium indicate that this population reproduced primarily clonally following the original hybridisation event, but that some recombination also occurred.,This observation allowed us to estimate the relative rates of sexual and asexual reproduction within this population, to our knowledge the first quantitative estimate of these events during the Leishmania life cycle.

Invertebrate stages of Leishmania are capable of genetic exchange during their extracellular growth and development in the sand fly vector.,Here we explore two variables: the ability of diverse L. major strains from across its natural range to undergo mating in pairwise tests; and the timing of the appearance of hybrids and their developmental stage associations within both natural (Phlebotomus duboscqi) and unnatural (Lutzomyia longipalpis) sand fly vectors.,Following co-infection of flies with parental lines bearing independent drug markers, doubly-drug resistant hybrid progeny were selected, from which 96 clonal lines were analyzed for DNA content and genotyped for parent alleles at 4-6 unlinked nuclear loci as well as the maxicircle DNA.,As seen previously, the majority of hybrids showed ‘2n’ DNA contents, but with a significant number of ‘3n’ and one ‘4n’ offspring.,In the natural vector, 97% of the nuclear loci showed both parental alleles; however, 3% (4/150) showed only one parental allele.,In the unnatural vector, the frequency of uniparental inheritance rose to 10% (27/275).,We attribute this to loss of heterozygosity after mating, most likely arising from aneuploidy which is both common and temporally variable in Leishmania.,As seen previously, only uniparental inheritance of maxicircle kDNA was observed.,Hybrids were recovered at similar efficiencies in all pairwise crosses tested, suggesting that L. major lacks detectable ‘mating types’ that limit free genetic exchange.,In the natural vector, comparisons of the timing of hybrid formation with the presence of developmental stages suggest nectomonads as the most likely sexually competent stage, with hybrids emerging well before the first appearance of metacyclic promastigotes.,These studies provide an important perspective on the prevalence of genetic exchange in natural populations of L. major and a guide for experimental studies to understand the biology of mating.

The indoor residual spraying programme for malaria vectors control was implemented in four districts of the Lake Victoria basin of Tanzania namely Ukerewe, Sengerema, Rorya andSerengeti.,Entomological monitoring activities were implemented in one sentinel village in each district to evaluate the efficacy of pirimiphos-methyl 300 CS sprayed on different wall surfaces and its impact against malaria vectors post-IRS intervention.,The residual decay rate of p-methyl 300 CS applied at a target dosage of 1g a.i./m2 on thesprayed wall surfaces was monitored for a period of 43 weeks post-IRSusing the WHO cone wall bioassay method.,The bioassays were performed by exposing 2-5 days old unfed susceptible female Anopheles gambiae s.s.,(Kisumu strain) to sprayed wall surfaces for a period of 30 minutes.,In each sentinel village, mosquito collection was carried out by trained community mosquito collectors.,Monthly mosquito collections were carried out from 6.00pm to 6.00am using CDC light traps and clay pot methods for indoors host seekingand outdoors resting mosquitoes respectively.,Six traps (2 CDC light traps and 4 clay pots) were set per sentinel village per night for28 consecutive days in a moon.,PCR and ELISA were used for mosquito species identification and sporozoite detection, respectively.,Based on the WHOPES recommendation, insecticides should have a minimum efficacy of ≥ 80% mosquito mortality at 24 hours post exposure on the sprayed wall surfaces to be considered effective.,In this study, p-methyl 300 CS was demonstrated to have a long residual efficacy of 21-43 weeks post-IRS on mud, cement, painted and wood wall surfaces.,Numberof anopheline mosquitoes decreased post-IRS interventions in all sentinel villages.,The highest numbers ofanopheline mosquitoes were collected in November-December, 38-43 weeks post-IRS.,A total of 270 female anopheline mosquitoes were analyzed by PCR; out of which 236 (87.4%) were An. gambiae s.l. and 34 (12.6%) were An. funestus group.,Of the 236 An. gambiae s.l.identified 12.6% (n = 34) were An. gambiae s.s. and 68.6% (n = 162) were An. arabiensis.,Ofthe 34 An. funestus group indentified 91.2% (n = 31) were An. parensis and 8.8% (n = 3) were An. rivulorum.,The overall Plasmodium falciparum sporozoite rate was 0.7% (n = 2,098).,Pirimiphos-methyl 300 CS was found to be effective for IRS in the Lake Victoria basin,Tanzania.,P-methyl 300 CShas a long residual efficacy on sprayed wall surfaces and therefore it is effective in controlling principal malaria vectors of An. gambiae s.l and An. funestus which rest on wall surfaces after and before feeding.

Recent global malaria burden modeling efforts have produced significantly different estimates, particularly in adult malaria mortality.,To measure malaria control progress, accurate malaria burden estimates across age groups are necessary.,We determined age-specific malaria mortality rates in western Kenya to compare with recent global estimates.,We collected data from 148,000 persons in a health and demographic surveillance system from 2003-2010.,Standardized verbal autopsies were conducted for all deaths; probable cause of death was assigned using the InterVA-4 model.,Annual malaria mortality rates per 1,000 person-years were generated by age group.,Trends were analyzed using Poisson regression.,From 2003-2010, in children <5 years the malaria mortality rate decreased from 13.2 to 3.7 per 1,000 person-years; the declines were greatest in the first three years of life.,In children 5-14 years, the malaria mortality rate remained stable at 0.5 per 1,000 person-years.,In persons ≥15 years, the malaria mortality rate decreased from 1.5 to 0.4 per 1,000 person-years.,The malaria mortality rates in young children and persons aged ≥15 years decreased dramatically from 2003-2010 in western Kenya, but rates in older children have not declined.,Sharp declines in some age groups likely reflect the national scale up of malaria control interventions and rapid expansion of HIV prevention services.,These data highlight the importance of age-specific malaria mortality ascertainment and support current strategies to include all age groups in malaria control interventions.

Malaria reduction is most efficiently achieved by vector control whereby human populations at high risk of contracting and transmitting the disease are protected from mosquito bites.,Here, we identify the presence of antibiotics in the blood of malaria-infected people as a new risk of increasing disease transmission.,We show that antibiotics in ingested blood enhance the susceptibility of Anopheles gambiae mosquitoes to malaria infection by disturbing their gut microbiota.,This effect is confirmed in a semi-natural setting by feeding mosquitoes with blood of children naturally infected with Plasmodium falciparum.,Antibiotic exposure additionally increases mosquito survival and fecundity, which are known to augment vectorial capacity.,These findings suggest that malaria transmission may be exacerbated in areas of high antibiotic usage, and that regions targeted by mass drug administration programs against communicable diseases may necessitate increased vector control.,The gut microbiota of malaria-transmitting mosquitoes contributes to the insects’ resistance to the parasite.,Here, Gendrin et al. show that antibiotics in ingested human blood alter the mosquito gut microbiota and increase the insect’s survival, fecundity and susceptibility to the parasites.

Understanding how mosquito vectors and malaria parasites interact is of fundamental interest, and it also offers novel perspectives for disease control.,Both the genetic and environmental contexts are known to affect the ability of mosquitoes to support malaria development and transmission, i.e., vector competence.,Although the role of environment has long been recognized, much work has focused on host and parasite genetic effects.,However, the last few years have seen a surge of studies revealing a great diversity of ways in which non-genetic factors can interfere with mosquito-Plasmodium interactions.,Here, we review the current evidence for such environmentally mediated effects, including ambient temperature, mosquito diet, microbial gut flora, and infection history, and we identify additional factors previously overlooked in mosquito-Plasmodium interactions.,We also discuss epidemiological implications, and the evolutionary consequences for vector immunity and parasite transmission strategies.,Finally, we propose directions for further research and argue that an improved knowledge of non-genetic influences on mosquito-Plasmodium interactions could aid in implementing conventional malaria control measures and contribute to the design of novel strategies.

Malaria rapid diagnostic tests (RDTs) play a key role in malaria management and control.,The PfHRP-2 based RDT is the most widely used RDT for malaria diagnosis in Ghana.,Deletion of pfhrp2 in Plasmodium falciparum parasites affect the diagnostic accuracy of PfHRP-2 based RDT kits.,Identifying the prevalence and distribution of P. falciparum parasites with deleted pfhrp2 is important for malaria control.,The purpose of this study was to identify and confirm the prevalence of pfhrp2 deletant P. falciparum parasites circulating within different regions of Ghana.,DNA was extracted from the membrane of spent CareStart™ PfHRP-2 RDT kits and dried filter paper blood blots using Chelex-100.,Exon 2 of pfhrp2 and pfhrp3 genes were amplified by polymerase chain reaction (PCR), resolved by agarose gel electrophoresis and visualized under UV light.,Microscopic analysis of blood smears from samples that were PfHRP-2 RDT positive revealed a parasite prevalence of 54/114 (47.4 %) and 2/26 (7.7 %) in Accra and Cape Coast, respectively.,PCR analysis increased parasite prevalence in the RDT positive samples to 94/114 (82.5 %) and 6/26 (23.1 %) in Accra and Cape Coast respectively.,The exon 2 of the pfhrp2 gene was deleted in 18/54 (33.3 %) of the microscopy confirmed and 36.2 % (34/94) of the PCR confirmed RDT positive samples collected in Accra.,No RDT sample, confirmed to contain parasites by either PCR or microscopy was negative by pfhrp2 exon 2 PCR in Cape Coast.,A survey of an additional 558 DBS revealed that 22.4 % (46/205) and 40 % (44/110) of PCR positive samples in Accra and Cape Coast, respectively, lacked the exon 2 region of pfhrp2 and possibly the entire pfhrp2 gene.,A high number of P. falciparum parasites, which lack pfhrp2 exon 2 gene have been identified in two communities in Ghana.,Continuous nationwide monitoring of the prevalence of pfhrp2 deletant parasites would be essential to malaria control.,The use of RDT kits that are effective at malaria diagnosis despite deletion of pfhrp2, such as the PfHRP-2/PfLDH combo RDT kit could enhance the diagnosis of clinical malaria in Ghana.

Multidrug-resistant parasites from the Amazon region caused the outbreak in the northern coastal region.,During 2010-2012, an outbreak of 210 cases of malaria occurred in Tumbes, in the northern coast of Peru, where no Plasmodium falciparum malaria case had been reported since 2006.,To identify the source of the parasite causing this outbreak, we conducted a molecular epidemiology investigation.,Microsatellite typing showed an identical genotype in all 54 available isolates.,This genotype was also identical to that of parasites isolated in 2010 in the Loreto region of the Peruvian Amazon and closely related to clonet B, a parasite lineage previously reported in the Amazon during 1998-2000.,These findings are consistent with travel history of index case-patients.,DNA sequencing revealed mutations in the Pfdhfr, Pfdhps, Pfcrt, and Pfmdr1 loci, which are strongly associated with resistance to chloroquine and sulfadoxine/pyrimethamine, and deletion of the Pfhrp2 gene.,These results highlight the need for timely molecular epidemiology investigations to trace the parasite source during malaria reintroduction events.

Diarrhoeal disease is responsible for 8.6% of global child mortality.,Recent epidemiological studies found the protozoan parasite Cryptosporidium to be a leading cause of paediatric diarrhoea, with particularly grave impact on infants and immunocompromised individuals.,There is neither a vaccine nor an effective treatment.,Here we establish a drug discovery process built on scalable phenotypic assays and mouse models that take advantage of transgenic parasites.,Screening a library of compounds with anti-parasitic activity, we identify pyrazolopyridines as inhibitors of Cryptosporidium parvum and Cryptosporidium hominis.,Oral treatment with the pyrazolopyridine KDU731 results in a potent reduction in intestinal infection of immunocompromised mice.,Treatment also leads to rapid resolution of diarrhoea and dehydration in neonatal calves, a clinical model of cryptosporidiosis that closely resembles human infection.,Our results suggest that the Cryptosporidium lipid kinase PI(4)K (phosphatidylinositol-4-OH kinase) is a target for pyrazolopyridines and that KDU731 warrants further preclinical evaluation as a drug candidate for the treatment of cryptosporidiosis.,The online version of this article (doi:10.1038/nature22337) contains supplementary material, which is available to authorized users.,The establishment of a drug-discovery screening pipeline for cryptosporidiosis, and identification of pyrazolopyridines as selective ATP-competitive inhibitors of the Cryptosporidium lipid kinase PI(4)K.,The online version of this article (doi:10.1038/nature22337) contains supplementary material, which is available to authorized users.,The apicomplexan parasite Cryptosporidium is a leading cause of paediatric diarrhoea, with high mortality in infants and individuals with weak immune systems.,Here, the authors report the establishment of a drug discovery screening pipeline for cryptosporidiosis, and identify pyrazolopyridines as selective ATP-competitive inhibitors of the Cryptosporidium lipid kinase PI(4)K.,The lead candidate, KDU731, inhibits growth of C. parvum and C. hominis in vitro, and demonstrated in vivo efficacy in immunocompromised mice and neonatal calves (a clinical model of human disease).,Moreover, KDU731 meets a broad range of safety and pharmacology criteria, and has potential as a much-needed therapeutic for treatment of cryptosporidiosis.,The online version of this article (doi:10.1038/nature22337) contains supplementary material, which is available to authorized users.

A major cause of the paucity of new starting points for drug discovery is the lack of interaction between academia and industry.,Much of the global resource in biology is present in universities, whereas the focus of medicinal chemistry is still largely within industry.,Open source drug discovery, with sharing of information, is clearly a first step towards overcoming this gap.,But the interface could especially be bridged through a scale-up of open sharing of physical compounds, which would accelerate the finding of new starting points for drug discovery.,The Medicines for Malaria Venture Malaria Box is a collection of over 400 compounds representing families of structures identified in phenotypic screens of pharmaceutical and academic libraries against the Plasmodium falciparum malaria parasite.,The set has now been distributed to almost 200 research groups globally in the last two years, with the only stipulation that information from the screens is deposited in the public domain.,This paper reports for the first time on 236 screens that have been carried out against the Malaria Box and compares these results with 55 assays that were previously published, in a format that allows a meta-analysis of the combined dataset.,The combined biochemical and cellular assays presented here suggest mechanisms of action for 135 (34%) of the compounds active in killing multiple life-cycle stages of the malaria parasite, including asexual blood, liver, gametocyte, gametes and insect ookinete stages.,In addition, many compounds demonstrated activity against other pathogens, showing hits in assays with 16 protozoa, 7 helminths, 9 bacterial and mycobacterial species, the dengue fever mosquito vector, and the NCI60 human cancer cell line panel of 60 human tumor cell lines.,Toxicological, pharmacokinetic and metabolic properties were collected on all the compounds, assisting in the selection of the most promising candidates for murine proof-of-concept experiments and medicinal chemistry programs.,The data for all of these assays are presented and analyzed to show how outstanding leads for many indications can be selected.,These results reveal the immense potential for translating the dispersed expertise in biological assays involving human pathogens into drug discovery starting points, by providing open access to new families of molecules, and emphasize how a small additional investment made to help acquire and distribute compounds, and sharing the data, can catalyze drug discovery for dozens of different indications.,Another lesson is that when multiple screens from different groups are run on the same library, results can be integrated quickly to select the most valuable starting points for subsequent medicinal chemistry efforts.

The coronavirus disease 2019 (COVID-19) pandemic has posed a unique challenge to health care systems globally.,To curb COVID-19 transmission, mitigation measures such as travel restrictions, border closures, curfews, lockdowns, and social distancing have been implemented.,However, these measures may directly and indirectly affect the delivery and utilization of essential health services, including malaria services.,The suspension of indoor residual spraying (IRS) and insecticide-treated net (ITN) distribution, shortages of malaria commodities, and reduced demand for health services have hindered the continued delivery of malaria services.,The overall goal of this analysis was to describe the trends in malaria incidence and mortality in Zimbabwe prior to and during the pandemic to understand the consequences of COVID-19-related changes in the delivery and utilization of malaria services.,Monthly data on the number of malaria cases and deaths by district for the period January 2017 to June 2020 were obtained from the national health management information system (HMIS).,District-level population data were obtained from the 2012 Census.,Malaria incidence per 1000 population and malaria deaths per 100,000 population were calculated for 2017, 2018, 2019, and 2020 and mapped to describe the spatial and temporal variation of malaria at the district level.,Compared to the same period in 2017, 2018 and 2019, there was an excess of over 30,000 malaria cases from January to June 2020.,The number of malaria deaths recorded in January to June 2020 exceeded the annual totals for 2018 and 2019.,District level maps indicated that areas outside high malaria burden provinces experienced higher than expected malaria incidence and mortality, suggesting potential outbreaks.,The observed surge in malaria cases and deaths in January to June 2020 coincided with the onset of COVID-19 in Zimbabwe.,While further research is needed to explore possible explanations for the observed trends, prioritizing the continuity of essential malaria services amid the COVID-19 pandemic remains crucial.,The online version contains supplementary material available at 10.1186/s12936-021-03770-7.

Detection of submicroscopic malaria in asymptomatic individuals is needed for eradication and remains a diagnostic gap in resource-limited settings.,Nonfalciparum clinical diagnostics are a second gap, as these infections have a low parasite density and are commonly undetected.,We describe an integrated, 60-min, ultrasensitive and specific CRISPR-based diagnostic for the four major pathogenic Plasmodium species that can fill these gaps.,Using the SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) platform, we designed assays with limits of detection below that recommended by the World Health Organization.,These assays have a simplified sample preparation method: the SHERLOCK parasite rapid extraction protocol, which eliminates complicated nucleic acid extraction steps.,Our work further translates the SHERLOCK platform into a field-deployable diagnostic.,Asymptomatic carriers of Plasmodium parasites hamper malaria control and eradication.,Achieving malaria eradication requires ultrasensitive diagnostics for low parasite density infections (<100 parasites per microliter blood) that work in resource-limited settings (RLS).,Sensitive point-of-care diagnostics are also lacking for nonfalciparum malaria, which is characterized by lower density infections and may require additional therapy for radical cure.,Molecular methods, such as PCR, have high sensitivity and specificity, but remain high-complexity technologies impractical for RLS.,Here we describe a CRISPR-based diagnostic for ultrasensitive detection and differentiation of Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae, using the nucleic acid detection platform SHERLOCK (specific high-sensitivity enzymatic reporter unlocking).,We present a streamlined, field-applicable, diagnostic comprised of a 10-min SHERLOCK parasite rapid extraction protocol, followed by SHERLOCK for 60 min for Plasmodium species-specific detection via fluorescent or lateral flow strip readout.,We optimized one-pot, lyophilized, isothermal assays with a simplified sample preparation method independent of nucleic acid extraction, and showed that these assays are capable of detection below two parasites per microliter blood, a limit of detection suggested by the World Health Organization.,Our P. falciparum and P. vivax assays exhibited 100% sensitivity and specificity on clinical samples (5 P. falciparum and 10 P. vivax samples).,This work establishes a field-applicable diagnostic for ultrasensitive detection of asymptomatic carriers as well as a rapid point-of-care clinical diagnostic for nonfalciparum malaria species and low parasite density P. falciparum infections.

Genetic polymorphisms in the human immune system modulate susceptibility to malaria.,However, there is a paucity of data on the contribution of immunogenetic variants to malaria susceptibility in infants, who present differential biological features related to the immaturity of their adaptive immune system, the protective effect of maternal antibodies and fetal haemoglobin.,This study investigated the association between genetic variation in innate immune response genes and malaria susceptibility during the first year of life in 656 infants from a birth cohort survey performed in Nanoro, Burkina Faso.,Seventeen single nucleotide polymorphisms (SNPs) in 11 genes of the immune system previously associated with different malaria phenotypes were genotyped using TaqMan allelic hybridization assays in a Fluidigm platform.,Plasmodium falciparum infection and clinical disease were documented by active and passive case detection.,Case-control association analyses for both alleles and genotypes were carried out using univariate and multivariate logistic regression.,For cytokines showing significant SNP associations in multivariate analyses, cord blood supernatant concentrations were measured by quantitative suspension array technology (Luminex).,Genetic variants in IL-1β (rs1143634) and FcγRIIA/CD32 (rs1801274)-both in allelic, dominant and co-dominant models-were significantly associated with protection from both P. falciparum infection and clinical malaria.,Furthermore, heterozygote individuals with rs1801274 SNP in FcγRIIA/CD32 showed higher IL-1RA levels compared to wild-type homozygotes (P = 0.024), a cytokine whose production is promoted by the binding of IgG immune complexes to Fcγ receptors on effector immune cells.,These findings indicate that genetic polymorphisms in genes driving innate immune responses are associated to malaria susceptibility during the first year of life, possibly by modulating production of inflammatory mediators.

The Brazilian Amazon is a hypo-endemic malaria region with nearly 300,000 cases each year.,A variety of genetic polymorphisms, particularly in erythrocyte receptors and immune response related genes, have been described to be associated with susceptibility and resistance to malaria.,In order to identify polymorphisms that might be associated with malaria clinical outcomes in a Brazilian Amazonian population, sixty-four human single nucleotide polymorphisms in 37 genes were analyzed using a Sequenom massARRAY iPLEX platform.,A total of 648 individuals from two malaria endemic areas were studied, including 535 malaria cases (113 individuals with clinical mild malaria, 122 individuals with asymptomatic infection and 300 individuals with history of previous mild malaria) and 113 health controls with no history of malaria.,The data revealed significant associations (p<0.003) between one SNP in the IL10 gene (rs1800896) and one SNP in the TLR4 gene (rs4986790) with reduced risk for clinical malaria, one SNP in the IRF1 gene (rs2706384) with increased risk for clinical malaria, one SNP in the LTA gene (rs909253) with protection from clinical malaria and one SNP in the TNF gene (RS1800750) associated with susceptibility to clinical malaria.,Also, a new association was found between a SNP in the CTL4 gene (rs2242665), located at the major histocompatibility complex III region, and reduced risk for clinical malaria.,This study represents the first association study from an Amazonian population involving a large number of host genetic polymorphisms with susceptibility or resistance to Plasmodium infection and malaria outcomes.,Further studies should include a larger number of individuals, refined parameters and a fine-scale map obtained through DNA sequencing to increase the knowledge of the Amazonian population genetic diversity.

In 2012, Tororo District had the highest malaria burden in Uganda with community Plasmodium prevalence of 48%.,To control malaria in the district, the Ministry of Health introduced universal distribution of long lasting insecticide-treated nets (LLINs) in 2013 and added indoor residual spraying (IRS) in 2014.,This study assessed malaria incidence, test positivity rates and outpatient (OPD) attendance due to malaria before and after vector control interventions.,This study was based on analysis of Health Management Information System (HMIS) secondary malaria surveillance data of 2,727,850 patient records in OPD registers of 61 health facilities from 2012 to 2015.,The analysis estimated monthly malaria incidence for the entire population and also separately for <5- and ≥5-year-olds before and after introduction of vector control interventions; determined laboratory test positivity rates and annual percentage of malaria cases in OPD.,Chi square for trends was used to analyse annual change in malaria incidence and logistic regression for monthly reduction.,Following universal LLINs coverage, the annual mean monthly malaria incidence fell from 95 cases in 2013 to 76 cases per 1000 in 2014 with no significant monthly reduction (OR = 0.99, 95% CI 0.96-1.01, P = 0.37).,Among children <5 years, the malaria incidence reduced from 130 to 100 cases per 1000 (OR = 0.98, 95% CI 0.97-1.00, P = 0.08) when LLINs were used alone in 2014, but declined to 45 per 1000 in 2015 when IRS was combined with LLINs (OR = 0.94, 95% CI 0.91-0.996, P < 0.0001).,Among individuals aged ≥5 years, mean monthly malaria incidence reduced from 59 to 52 cases per 1000 (OR = 0.99, 95% CI 0.97-1.02, P = 0.8) when LLINs were used alone in 2014, but reduced significantly to 25 per 1000 in 2015 (OR = 0.91, 95% CI 0.88-0.94, P < 0.0001).,Malaria test positivity rate reduced from 57% in 2013 to 30% (Chi = 15, P < 0.0001) in 2015.,Slide positivity rate reduced from 45% in 2013 to 21% in 2015 (P = 0.004) while RDT positivity declined from 69 to 40%.,A rapid reduction in malaria incidence was observed in Tororo District following the introduction of IRS in addition to LLINs.,There was no significant reduction in malaria incidence following universal distribution of LLINs to communities before introduction of IRS.

To investigate risk factors, including reported net use, for Plasmodium infection and anaemia among school children and to explore variations in effects across different malaria ecologies occurring in Kenya.,This study analysed data for 49 975 school children in 480 schools surveyed during a national school malaria survey, 2008-2010.,Mixed effects logistic regression was used to investigate factors associated with Plasmodium infection and anaemia within different malaria transmission zones.,Insecticide-treated net (ITN) use was associated with reduction in the odds of Plasmodium infection in coastal and western highlands epidemic zones and among boys in the lakeside high transmission zone.,Other risk factors for Plasmodium infection and for anaemia also varied by zone.,Plasmodium infection was negatively associated with increasing socio-economic status in all transmission settings, except in the semi-arid north-east zone.,Plasmodium infection was a risk factor for anaemia in lakeside high transmission, western highlands epidemic and central low-risk zones, whereas ITN use was only associated with lower levels of anaemia in coastal and central zones and among boys in the lakeside high transmission zone.,The risk factors for Plasmodium infection and anaemia, including the protective associations with ITN use, vary according to malaria transmission settings in Kenya, and future efforts to control malaria and anaemia should take into account such heterogeneities among school children.

Plasmodium vivax infection has been gaining attention because of its re-emergence in several parts of the world.,Southeastern Turkey is one of the places in which persistent focal malaria caused exclusively by P. vivax parasites occurs.,Although control and elimination studies have been underway for many years, no detailed study has been conducted to understand the mechanisms underlying the ineffective control of malaria in this region.,Here, for the first time, using serologic markers we try to extract as much information as possible in this region to get a glimpse of P. vivax transmission.,We conducted a sero-immunological study, evaluating antibody responses of individuals living in Sanliurfa to four different P. vivax antigens; three blood-stage antigens (PvMSP119, PvAMA1-ecto, and PvSERA4) and one pre-erythrocytic stage antigen (PvCSP).,The results suggest that a prior history of malaria infection and age can be determining factors for the levels and sustainability of naturally acquired antibodies.,Significantly higher antibody responses to all the studied antigens were observed in blood smear-negative individuals with a prior history of malaria infection.,Moreover, these individuals were significantly older than blood smear-negative individuals with no prior history of infection.,These data from an area of sole P. vivax-endemic region may have important implications for the global malaria control/elimination programs and vaccine design.

The evaluation of malaria transmission intensity is a crucial indicator for estimating the burden of malarial disease.,In this respect, entomological and parasitological methods present limitations, especially in low transmission areas.,The present study used a sensitive multiplex assay to assess the exposure to Plasmodium falciparum infection in children living in an area of low endemicity.,In three Senegalese villages, specific antibody (IgG) responses to 13 pre-erythrocytic P. falciparum peptides derived from Lsa1, Lsa3, Glurp, Salsa, Trap, Starp, Csp and Pf11.1 proteins were simultaneously evaluated before (June), at the peak (September) and after (December) the period of malaria transmission, in children aged from 1 to 8 years.,Compared to other antigens, a high percentage of seropositivity and specific antibody levels were detected with Glurp, Salsa1, Lsa3NR2, and Lsa1J antigens.,The seropositivity increased with age for all tested antigens.,Specific IgG levels to Glurp, Salsa1, Lsa3NR2, and Lsa1J were significantly higher in P. falciparum infected children compared to non-infected and this increase is significantly correlated with parasite density.,The multiplex assay represents a useful technology for a serological assessment of rapid variations in malaria transmission intensity, especially in a context of low parasite rates.,The use of such combined serological markers (i.e.,Glurp, Lsa1, Lsa3, and Salsa) could offer the opportunity to examine these variations over time, and to evaluate the efficacy of integrated malaria control strategies.

Vaccination is an efficient means of combating infectious disease burden globally.,However, routine vaccines for the world's major human parasitic diseases do not yet exist.,Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections.,We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines.,We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases-malaria, toxoplasmosis, and leishmaniasis.,The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria.,However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored.,In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma, and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach.,Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.

Despite 40 years of control efforts, onchocerciasis (river blindness) remains one of the most important neglected tropical diseases, with 17 million people affected.,The etiological agent, Onchocerca volvulus, is a filarial nematode with a complex lifecycle involving several distinct stages in the definitive host and blackfly vector.,The challenges of obtaining sufficient material have prevented high-throughput studies and the development of novel strategies for disease control and diagnosis.,Here, we utilize the closest relative of O. volvulus, the bovine parasite Onchocerca ochengi, to compare stage-specific proteomes and host-parasite interactions within the secretome.,We identified a total of 4260 unique O. ochengi proteins from adult males and females, infective larvae, intrauterine microfilariae, and fluid from intradermal nodules.,In addition, 135 proteins were detected from the obligate Wolbachia symbiont.,Observed protein families that were enriched in all whole body extracts relative to the complete search database included immunoglobulin-domain proteins, whereas redox and detoxification enzymes and proteins involved in intracellular transport displayed stage-specific overrepresentation.,Unexpectedly, the larval stages exhibited enrichment for several mitochondrial-related protein families, including members of peptidase family M16 and proteins which mediate mitochondrial fission and fusion.,Quantification of proteins across the lifecycle using the Hi-3 approach supported these qualitative analyses.,In nodule fluid, we identified 94 O. ochengi secreted proteins, including homologs of transforming growth factor-β and a second member of a novel 6-ShK toxin domain family, which was originally described from a model filarial nematode (Litomosoides sigmodontis).,Strikingly, the 498 bovine proteins identified in nodule fluid were strongly dominated by antimicrobial proteins, especially cathelicidins.,This first high-throughput analysis of an Onchocerca spp. proteome across the lifecycle highlights its profound complexity and emphasizes the extremely close relationship between O. ochengi and O. volvulus.,The insights presented here provide new candidates for vaccine development, drug targeting and diagnostic biomarkers.

Strongyloidiasis is a gut infection with Strongyloides stercoralis which is common world wide.,Chronic infection usually causes a skin rash, vomiting, diarrhoea or constipation, and respiratory problems, and it can be fatal in people with immune deficiency.,It may be treated with ivermectin or albendazole or thiabendazole.,To assess the effects of ivermectin versus benzimidazoles (albendazole and thiabendazole) for treating chronic strongyloides infection.,We searched the Cochrane Infectious Diseases Group Specialized Register (24 August 2015); the Cochrane Central Register of Controlled Trials (CENTRAL), published in the Cochrane Library; MEDLINE (January 1966 to August 2015); EMBASE (January 1980 to August 2015); LILACS (August 2015); and reference lists of articles.,We also searched the metaRegister of Controlled Trials (mRCT) using 'strongyloid*' as a search term, reference lists, and conference abstracts.,Randomized controlled trials of ivermectin versus albendazole or thiabendazole for treating chronic strongyloides infection.,Two review authors independently extracted data and assessed risk of bias in the included trials.,We used risk ratios (RRs) with 95% confidence intervals (CIs) and fixed‐ or random‐effects models.,We pooled adverse event data if the trials were sufficiently similar in their adverse event definitions.,We included seven trials, enrolling 1147 participants, conducted between 1994 and 2011 in different locations (Africa, Southeast Asia, America and Europe).,In trials comparing ivermectin with albendazole, parasitological cure was higher with ivermectin (RR 1.79, 95% CI 1.55 to 2.08; 478 participants, four trials, moderate quality evidence).,There were no statistically significant differences in adverse events (RR 0.80, 95% CI 0.59 to 1.09; 518 participants, four trials, low quality evidence).,In trials comparing ivermectin with thiabendazole, there was little or no difference in parasitological cure (RR 1.07, 95% CI 0.96 to 1.20; 467 participants, three trials, low quality evidence).,However, adverse events were less common with ivermectin (RR 0.31, 95% CI 0.20 to 0.50; 507 participants; three trials, moderate quality evidence).,In trials comparing different dosages of ivermectin, taking a second dose of 200 μg/kg of ivermectin was not associated with higher cure in a small subgroup of participants (RR 1.02, 95% CI 0.94 to 1.11; 94 participants, two trials).,Dizziness, nausea, and disorientation were commonly reported in all drug groups.,There were no reports of serious adverse events or death.,Ivermectin results in more people cured than albendazole, and is at least as well tolerated.,In trials of ivermectin with thiabendazole, parasitological cure is similar but there are more adverse events with thiabendazole.,16 April 2019,Update pending,Studies awaiting assessment,The CIDG is currently examining a new search conducted in April 2019 for potentially relevant studies.,These studies have not yet been incorporated into this Cochrane Review.,Ivermectin versus benzimidazoles for treating Strongyloides stercoralis infection,What is strongyloides infection and how might ivermectin work,Strongyloides stercoralis is a parasite that lives in the gut of infected people.,The infection is not serious for most people, but it can be fatal in people with immune deficiency.,People become infected when they come in contact with soil or water contaminated with infectious worms.,The chronic infection usually causes skin rash, vomiting, diarrhoea, and constipation, and respiratory problems, such as asthma‐like illness.,This disease may be treated with ivermectin or albendazole or thiabendazole.,We wanted to know if ivermectin was better or worse than the other alternative therapies.,What the research says,We reviewed the evidence about the effect of ivermectin compared with albendazole and thiabendazole.,After searching for relevant trials up to August 2015, we included seven randomized controlled trials, enrolling 1147 adults with chronic strongyloides infection, conducted between 1994 and 2011 in different locations (Africa, Southeast Asia, America, and Europe).,Four trials assessed the effectiveness of ivermectin compared with albendazole and three trials assessed the effectiveness of ivermectin compared with thiabendazole.,Comparison ivermectin versus albendazole,Treatment with ivermectin probably cures more people than albendazole (moderate quality evidence), and may be equally or better tolerated (low quality evidence).,The included trials did not report serious adverse events or death.,Comparison ivermectin versus thiabendazole,Treatment with ivermectin and thiabendazole may cure similar numbers of people with strongyloides infection (low quality evidence), but ivermectin is probably better tolerated (moderate quality evidence).,The included trials did not report serious adverse events or death.

The control of helminth infections and prevention of anemia in developing countries are of considerable public health importance.,The purpose of this study was to determine patterns and risk factors of helminth infections and anemia in a rural and a peri-urban community of Zanzibar, Tanzania, in the context of national helminth control programs.,We carried out a community-based cross-sectional study in 454 individuals by examining at least two stool samples with different methods for soil-transmitted helminths (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, and Trichuris trichiura) and one urine sample for Schistosoma haematobium.,Finger-prick blood was taken to estimate anemia levels and to detect antibody reactions against ascariasis, strongyloidiasis and schistosomiasis, using an enzyme-linked immunosorbent assay (ELISA) approach.,Parasitological methods determined a helminth prevalence of 73.7% in the rural, and 48.9% in the peri-urban setting.,Most helminth infections were of light intensity with school-aged children showing the highest intensities.,Multiple helminth species infections were pervasive in rural dwellers regardless of age.,More than half of the participants were anemic, with a particularly high prevalence in the peri-urban setting (64.7%).,Risk factors for helminth infections were age, sex, consumption of raw vegetables or salad, recent travel history, and socio-economic status.,After several years of chemotherapy-based morbidity control efforts in Zanzibar, helminth prevalences are still high and anemia is common, but helminth infection intensities are low.,Hence, chemotherapy should be continued, and complemented with improved access to clean water, adequate sanitation, and health education, along with poverty alleviation measures for a more enduring impact.

Despite the recent progress in establishing the patterns of insecticide resistance in the major malaria vector Anopheles funestus, Central African populations of this species remain largely uncharacterised.,To bridge this important gap and facilitate the implementation of suitable control strategies against this vector, we characterised the resistance patterns of An. funestus population from northern Cameroon.,Collection of indoor-resting female mosquitoes in Gounougou (northern Cameroon) in 2012 and 2015 revealed a predominance of An. funestus during dry season.,WHO bioassays performed using F1 An. funestus revealed that the population was multiple resistant to several insecticide classes including pyrethroids (permethrin, deltamethrin, lambda-cyhalothrin and etofenprox), carbamates (bendiocarb) and organochlorines (DDT and dieldrin).,However, a full susceptibility was observed against the organophosphate malathion.,Bioassays performed with 2015 collection revealed that resistance against pyrethroids and DDT is increasing.,PBO synergist assays revealed a significant recovery of susceptibility for all pyrethroids but less for DDT.,Analysis of the polymorphism of a portion of the voltage-gated sodium channel gene (VGSC) revealed the absence of the L1014F/S kdr mutation but identified 3 novel amino acid changes I877L, V881L and A1007S.,However, no association was established between VGSC polymorphism and pyrethroid/DDT resistance.,The DDT resistant 119F-GSTe2 allele (52%) and the dieldrin resistant 296S-RDL allele (45%) were detected in Gounougou.,Temporal analysis between 2006, 2012 and 2015 collections revealed that the 119F-GSTe2 allele was relatively stable whereas a significant decrease is observed for 296S-RDL allele.,This multiple resistance coupled with the temporal increased in resistance intensity highlights the need to take urgent measures to prolong the efficacy of current insecticide-based interventions against An. funestus in this African region.

The use of antimalarial drugs for prevention and treatment is a major strategy in the prevention of malaria in pregnancy.,Although sulphadoxine-pyrimethamine (SP) is currently recommended for intermittent preventive treatment of malaria during pregnancy in Nigeria, previously used drugs for prophylaxis such as chloroquine (CQ) and pyrimethamine are accessible as they are purchased over the counter.,This study describes the markers of absence or presence of resistance to quinoline (Pfcrt and Pfmdr 1) and type 1 antifolate antimalarial medicines (Pfdhfr).,Plasmodium falciparum-positive dried blood spots from pregnant women attending antenatal clinics for the first time during current pregnancy were investigated for the presence of mutations at codons 72-76 of Plasmodium falciparum chloroquine resistance transporter (Pfcrt) gene by real time polymerase chain reaction (PCR) using haplotype-specific probes.,PCR followed by sequence analysis was used to identify mutations at codons 86, 184, 1034, 1042 and 1246 of P. falciparum multi-drug resistance-1 (Pfmdr1) gene; and codons 16, 50, 51, 59, 108, 140 and 164 of Pfdhfr gene.,Two haplotypes of Pfcrt (n = 54) were observed: CVMNK 13(24.2%) and CVIET 41 (75.9%) of the samples.,The SVMNT haplotype was absent in this population.,The Pfmdr1 (n = 28) haplotypes were NYSND 15(53.6%), YYSND 5(17.9%), NFSND 6(21.4%) and YFSND 2(7.1%).,The Pfdhfr (n = 15) were ACNCSVI 4(26.7%), and ACICNSVI 1(6.7%) and ACIRNVI 10 (66.7%).,The rate of occurrence of Pfcrt 76T, Pfdhfr108N, Pfmdr186Yand184F were 75.9%, 73.3%, 25% and 28.1% respectively.,The Pfmdr1 86Y was associated with low parasitaemia (median = 71 parasites/μl, P = 0.024) while Pfcrt 76T was associated with young maternal age (mean 24.1 ± 4.5 years; P = 0.006).,The median parasitaemia were similar (P>0.05) in wild and mutant strains of Pfcrt 76, Pfmdr1 184 and Pfdhfr 108.,There was no association between gravidity or gestational age of the women and presence of mutations in the Pfcrt, Pfmdr1 or Pfdhfr genes (P>0.05).,Markers of resistance to chloroquine and pyrimethamine were high, whereas cycloguanil-resistance marker was not present in the studied population.,The low level of mutations in the Pfmdr1gene indicates likely efficacy of amodiaquine against malaria in pregnancy.

Malaria control in Africa relies extensively on indoor residual spraying (IRS) and insecticide-treated nets (ITNs).,IRS typically targets mosquitoes resting on walls, and in few cases, roofs and ceilings, using contact insecticides.,Unfortunately, little attention is paid to where malaria vectors actually rest indoors, and how such knowledge could be used to improve IRS.,This study investigated preferred resting surfaces of two major malaria vectors, Anopheles funestus and Anopheles arabiensis, inside four common house types in rural south-eastern Tanzania.,The assessment was done inside 80 houses including: 20 with thatched roofs and mud walls, 20 with thatched roofs and un-plastered brick walls, 20 with metal roofs and un-plastered brick walls, and 20 with metal roofs and plastered brick walls, across four villages.,In each house, resting mosquitoes were sampled in mornings (6 a.m.-8 a.m.), evenings (6 p.m.-8 p.m.) and at night (11 p.m.-12.00 a.m.) using Prokopack aspirators from multiple surfaces (walls, undersides of roofs, floors, furniture, utensils, clothing, curtains and bed nets).,Overall, only 26% of An. funestus and 18% of An. arabiensis were found on walls.,In grass-thatched houses, 33-55% of An. funestus and 43-50% of An. arabiensis rested under roofs, while in metal-roofed houses, only 16-20% of An. funestus and 8-30% of An. arabiensis rested under roofs.,Considering all data together, approximately 40% of mosquitoes rested on surfaces not typically targeted by IRS, i.e. floors, furniture, utensils, clothing and bed nets.,These proportions were particularly high in metal-roofed houses (47-53% of An. funestus; 60-66% of An. arabiensis).,While IRS typically uses contact insecticides to target adult mosquitoes on walls, and occasionally roofs and ceilings, significant proportions of vectors rest on surfaces not usually sprayed.,This gap exceeds one-third of malaria mosquitoes in grass-thatched houses, and can reach two-thirds in metal-roofed houses.,Where field operations exclude roofs during IRS, the gaps can be much greater.,In conclusion, there is need for locally-obtained data on mosquito resting behaviours and how these influence the overall impact and costs of IRS.,This study also emphasizes the need for alternative approaches, e.g. house screening, which broadly tackle mosquitoes beyond areas reachable by IRS and ITNs.

Community-based service delivery is vital to the effectiveness, affordability and sustainability of vector control generally, and to labour-intensive larval source management (LSM) programmes in particular.,The institutional evolution of a city-level, community-based LSM programme over 14 years in urban Dar es Salaam, Tanzania, illustrates how operational research projects can contribute to public health governance and to the establishment of sustainable service delivery programmes.,Implementation, management and governance of this LSM programme is framed within a nested set of spatially-defined relationships between mosquitoes, residents, government and research institutions that build upward from neighbourhood to city and national scales.,The clear hierarchical structure associated with vertical, centralized management of decentralized, community-based service delivery, as well as increasingly clear differentiation of partner roles and responsibilities across several spatial scales, contributed to the evolution and subsequent growth of the programme.,The UMCP was based on the principle of an integrated operational research project that evolved over time as the City Council gradually took more responsibility for management.,The central role of Dar es Salaam’s City Council in coordinating LSM implementation enabled that flexibility; the institutionalization of management and planning in local administrative structures enhanced community-mobilization and funding possibilities at national and international levels.,Ultimately, the high degree of program ownership by the City Council and three municipalities, coupled with catalytic donor funding and technical support from expert overseas partners have enabled establishment of a sustainable, internally-funded programme implemented by the National Ministry of Health and Social Welfare and supported by national research and training institutes.

Historically, Plasmodium vivax malaria has been one of the most highly endemic parasitic diseases in the Korean Peninsula.,Until the 1970s, vivax malaria was rarely directly lethal and was controlled through the Korean Government Program administered by the National Malaria Eradication Service in association with the World Health Organization’s Global Malaria Eradication Program.,Vivax malaria has re-emerged in 1993 near the Demilitarized Zone between South and North Korea and has since become an endemic infectious disease that now poses a serious public health threat through local transmission in the Republic of Korea.,This review presents major lessons learned from past and current malaria research, including epidemiological and biological characteristics of the re-emergent disease, and considers some interesting patterns of diversity.,Among other features, this review highlights temporal changes in the genetic makeup of the parasitic population, patient demographic features, and spatial distribution of cases, which all provide insight into the factors contributing to local transmission.,The data indicate that vivax malaria in Korea is not expanding exponentially.,However, continued surveillance is needed to prevent future resurgence.

The Republic of Korea (South Korea) is one of the countries where vivax malaria had been successfully eradicated by the late 1970s.,However, re-emergence of vivax malaria in South Korea was reported in 1993.,Several epidemiological studies and some genetic studies using antigenic molecules of Plasmodium vivax in the country have been reported, but the evolutionary history of P. vivax has not been fully understood.,In this study, the origin of the South Korean P. vivax population was estimated by molecular phylogeographic analysis.,A haplotype network analysis based on P. vivax mitochondrial (mt) DNA sequences was conducted on 11 P. vivax isolates from South Korea and another 282 P. vivax isolates collected worldwide.,The network analysis of P. vivax mtDNA sequences showed that the coexistence of two different groups (A and B) in South Korea.,Groups A and B were identical or close to two different populations in southern China.,Although the direct introduction of the two P. vivax populations in South Korea were thought to have been from North Korea, the results of this analysis suggest the genealogical origin to be the two different populations in southern China.

In Canada, surveys of enteric parasites in dogs and cats have been reported sporadically over the past 40 years, mostly focusing on a specific region.,The present work was performed to determine the current prevalence of various parasites in fecal samples from shelter dogs and cats across the Canadian provinces.,A total of 1086 dog and 636 cat fecal samples from 26 shelters were analysed using a sugar solution double centrifugal flotation technique.,Prevalences (national, regional, provincial, age and parasite-specific), were calculated and compared using the Fisher-Exact test.,A multiplex PCR was performed to distinguish Taenia spp, Echinococcus granulosus and E. multilocularis on samples positive for taeniid eggs.,Overall, 33.9% of dogs and 31.8% of cats were positive for at least one parasite.,Toxocara canis and T. cati were the most prevalent parasite present in fecal samples followed by Cystoisospora spp.,Prevalence in dogs was similar across the Atlantic, East, West and Pacific regions, while prevalence in cats varied regionally.,Eggs of E. granulosus/E. canadensis were detected in samples from dogs from BC, AB, and ON.,Data from this study will help in the development of strategies, based on the level of risk per geographic location for the prevention and response to these parasites in pets and free-roaming and shelter animals in Canada.

Mongolian gerbils and Wistar rats were inoculated orally with 240 and 2,500 Toxocara cati embryonated eggs, respectively, to evaluate the larval recovery in different tissues and organs, such as the liver, lungs, heart, kidney, and skeletal muscles after 5, 30, 49, 70, and 92 days post-infection (PI).,Larval recovery rates were 1.7-30.0% in Mongolian gerbils on days 5-92 PI and 0.2-3.8% in rats on the same days.,These results indicate that Mongolian gerbils and Wistar rats are suitable experimental paratenic hosts for the study of neurological toxocariasis as well as visceral toxocariasis.

The contribution of community medicine distributors (CMD) to prompt health service delivery in areas described as “hard-to-reach” is important but the value of their work time remains unknown and thus makes it difficult to design appropriate regular financial incentives to motivate them.,This makes CMDs feel their efforts are not recognized.,An attempt to estimate the value of 54 CMDs’ work time involved in community case management of malaria (CCMm) in a rural district in Ghana is presented.,Time spent by CMDs on CCMm activities were recorded for a period of 12 months to determine the work-time value.,Cost analysis was performed in Microsoft Excel with data from CMD records and at 2007 market price in Ghana.,A CMD spent 4.8 hours, [95% CI: 3.9; 5.3] on all CCMm-related activities per day.,The time value of CMD work ranged from GH¢ 2.04 (US$ 2.24) to GH¢ 4.1 [US$ 4.6] per week and GH¢ 19.2 - 86.4 (US$ 21.10-94.95) per month.,The gross wage outside CCMm as reported by CMD was GH¢ 58.4 [US$ 64.69] and value of foregone income of GH¢ 86.40 (US$94.95) per month, about 14-times higher than the monthly incentives of GH¢ 6.0 given by the CCMm programme.,The value of work time and the foregone income of CMDs in CCMm are high and yet there are no regular and sustainable incentives provided for them.,The results are significant to policy in designing incentives to motivate CMDs in large-scale implementation of CCMm.

Early and accurate diagnosis of malaria followed by prompt treatment reduces the risk of severe disease in malaria endemic regions.,Presumptive treatment of malaria is widely practised where microscopy or rapid diagnostic tests (RDTs) are not readily available.,With the introduction of artemisinin-based combination therapy (ACT) for treatment of malaria in many low-resource settings, there is need to target treatment to patients with parasitologically confirmed malaria in order to improve quality of care, reduce over consumption of anti-malarials, reduce drug pressure and in turn delay development and spread of drug resistance.,This study evaluated the effect of malaria RDTs on health workers' anti-malarial drug (AMD) prescriptions among outpatients at low level health care facilities (LLHCF) within different malaria epidemiological settings in Uganda.,All health workers (HWs) in 21 selected intervention (where RDTs were deployed) LLHF were invited for training on the use RDTs.,All HWs were trained to use RDTs for parasitological diagnosis of all suspected malaria cases irrespective of age.,Five LLHCFs with clinical diagnosis (CD only) were included for comparison.,Subsequently AMD prescriptions were compared using both a 'pre - post' and 'intervention - control' analysis designs.,In-depth interviews of the HWs were conducted to explore any factors that influence AMD prescription practices.,A total of 166,131 out-patient attendances (OPD) were evaluated at 21 intervention LLHCFs.,Overall use of RDTs resulted in a 38% point reduction in AMD prescriptions.,There was a two-fold reduction (RR 0.62, 95% CI 0.55-0.70) in AMD prescription with the greatest reduction in the hypo-endemic setting (RR 0.46 95% CI 0.51-0.53) but no significant change in the urban setting (RR1.01, p-value = 0.820).,Over 90% of all eligible OPD patients were offered a test.,An average of 30% (range 25%-35%) of the RDT-negative fever patients received AMD prescriptions.,When the test result was negative, children under five years of age were two to three times more likely (OR 2.6 p-value <0.001) to receive anti-malarial prescriptions relative to older age group.,Of the 63 HWs interviewed 92% believed that a positive RDT result confirmed malaria, while only 49% believed that a negative RDT result excluded malaria infection.,Use of RDTs resulted in a 2-fold reduction in anti-malarial drug prescription at LLHCFs.,The study demonstrated that RDT use is feasible at LLHCFs, and can lead to better targetting of malaria treatment.,Nationwide deployment of RDTs in a systematic manner should be prioritised in order to improve fever case management.,The process should include plans to educate HWs about the utility of RDTs in order to maximize acceptance and uptake of the diagnostic tools and thereby leading to the benefits of parasitological diagnosis of malaria.

Since 2000, the scale-up of malaria control interventions has substantially reduced morbidity and mortality caused by the disease globally, fuelling bold aims for disease elimination.,In tandem with increased availability of geospatially resolved data, malaria control programmes increasingly use high-resolution maps to characterise spatially heterogeneous patterns of disease risk and thus efficiently target areas of high burden.,We updated and refined the Plasmodium falciparum parasite rate and clinical incidence models for sub-Saharan Africa, which rely on cross-sectional survey data for parasite rate and intervention coverage.,For malaria endemic countries outside of sub-Saharan Africa, we produced estimates of parasite rate and incidence by applying an ecological downscaling approach to malaria incidence data acquired via routine surveillance.,Mortality estimates were derived by linking incidence to systematically derived vital registration and verbal autopsy data.,Informed by high-resolution covariate surfaces, we estimated P falciparum parasite rate, clinical incidence, and mortality at national, subnational, and 5 × 5 km pixel scales with corresponding uncertainty metrics.,We present the first global, high-resolution map of P falciparum malaria mortality and the first global prevalence and incidence maps since 2010.,These results are combined with those for Plasmodium vivax (published separately) to form the malaria estimates for the Global Burden of Disease 2017 study.,The P falciparum estimates span the period 2000-17, and illustrate the rapid decline in burden between 2005 and 2017, with incidence declining by 27·9% and mortality declining by 42·5%.,Despite a growing population in endemic regions, P falciparum cases declined between 2005 and 2017, from 232·3 million (95% uncertainty interval 198·8-277·7) to 193·9 million (156·6-240·2) and deaths declined from 925 800 (596 900-1 341 100) to 618 700 (368 600-952 200).,Despite the declines in burden, 90·1% of people within sub-Saharan Africa continue to reside in endemic areas, and this region accounted for 79·4% of cases and 87·6% of deaths in 2017.,High-resolution maps of P falciparum provide a contemporary resource for informing global policy and malaria control planning, programme implementation, and monitoring initiatives.,Amid progress in reducing global malaria burden, areas where incidence trends have plateaued or increased in the past 5 years underscore the fragility of hard-won gains against malaria.,Efforts towards elimination should be strengthened in such areas, and those where burden remained high throughout the study period.,Bill & Melinda Gates Foundation.

Haiti has a set a target of eliminating malaria by 2020.,However, information on malaria vector research in Haiti is not well known.,This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti.,A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO.,The following search terms were used: malaria, Haiti, Anopheles, and vector control.,A total of 132 references were identified with 40 high quality references deemed relevant and included in this review.,Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control.,In the last 15 years (2000-2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti.,Overall, the general literature on malaria vector research in Haiti is limited and dated.,Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola.,However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination.

The only currently available drug that effectively removes malaria hypnozoites from the human host is primaquine.,The use of 8-aminoquinolines is hampered by haemolytic side effects in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals.,Recently a number of qualitative and a quantitative rapid diagnostic test (RDT) format have been developed that provide an alternative to the current standard G6PD activity assays.,The WHO has recently recommended routine testing of G6PD status prior to primaquine radical cure whenever possible.,A workshop was held in the Philippines in early 2015 to discuss key challenges and knowledge gaps that hinder the introduction of routine G6PD testing.,Two point-of-care (PoC) test formats for the measurement of G6PD activity are currently available: qualitative tests comparable to malaria RDT as well as biosensors that provide a quantitative reading.,Qualitative G6PD PoC tests provide a binomial test result, are easy to use and some products are comparable in price to the widely used fluorescent spot test.,Qualitative test results can accurately classify hemizygous males, heterozygous females, but may misclassify females with intermediate G6PD activity.,Biosensors provide a more complex quantitative readout and are better suited to identify heterozygous females.,While associated with higher costs per sample tested biosensors have the potential for broader use in other scenarios where knowledge of G6PD activity is relevant as well.,The introduction of routine G6PD testing is associated with additional costs on top of routine treatment that will vary by setting and will need to be assessed prior to test introduction.,Reliable G6PD PoC tests have the potential to play an essential role in future malaria elimination programmes, however require an improved understanding on how to best integrate routine G6PD testing into different health settings.,The online version of this article (doi:10.1186/s12936-015-0896-8) contains supplementary material, which is available to authorized users.

Ric Price and colleagues use hospital-based surveillance data to estimate the risk of severe anemia and mortality associated with endemic Plasmodium species in southern Papua, Indonesia.,Please see later in the article for the Editors' Summary,The burden of anemia attributable to non-falciparum malarias in regions with Plasmodium co-endemicity is poorly documented.,We compared the hematological profile of patients with and without malaria in southern Papua, Indonesia.,Clinical and laboratory data were linked for all patients presenting to a referral hospital between April 2004 and December 2012.,Data were available on patient demographics, malaria diagnosis, hemoglobin concentration, and clinical outcome, but other potential causes of anemia could not be identified reliably.,Of 922,120 patient episodes (837,989 as outpatients and 84,131 as inpatients), a total of 219,845 (23.8%) were associated with a hemoglobin measurement, of whom 67,696 (30.8%) had malaria.,Patients with P. malariae infection had the lowest hemoglobin concentration (n = 1,608, mean = 8.93 [95% CI 8.81-9.06]), followed by those with mixed species infections (n = 8,645, mean = 9.22 [95% CI 9.16-9.28]), P. falciparum (n = 37,554, mean = 9.47 [95% CI 9.44-9.50]), and P. vivax (n = 19,858, mean = 9.53 [95% CI 9.49-9.57]); p-value for all comparisons <0.001.,Severe anemia (hemoglobin <5 g/dl) was present in 8,151 (3.7%) patients.,Compared to patients without malaria, those with mixed Plasmodium infection were at greatest risk of severe anemia (adjusted odds ratio [AOR] 3.25 [95% CI 2.99-3.54]); AORs for severe anaemia associated with P. falciparum, P. vivax, and P. malariae were 2.11 (95% CI 2.00-2.23), 1.87 (95% CI 1.74-2.01), and 2.18 (95% CI 1.76-2.67), respectively, p<0.001.,Overall, 12.2% (95% CI 11.2%-13.3%) of severe anemia was attributable to non-falciparum infections compared with 15.1% (95% CI 13.9%-16.3%) for P. falciparum monoinfections.,Patients with severe anemia had an increased risk of death (AOR = 5.80 [95% CI 5.17-6.50]; p<0.001).,Not all patients had a hemoglobin measurement, thus limitations of the study include the potential for selection bias, and possible residual confounding in multivariable analyses.,In Papua P. vivax is the dominant cause of severe anemia in early infancy, mixed P. vivax/P. falciparum infections are associated with a greater hematological impairment than either species alone, and in adulthood P. malariae, although rare, is associated with the lowest hemoglobin concentration.,These findings highlight the public health importance of integrated genus-wide malaria control strategies in areas of Plasmodium co-endemicity.,Please see later in the article for the Editors' Summary,Malaria-a mosquito-borne parasitic disease-is a global public health problem.,Five parasites cause malaria-Plasmodium falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi.,Of these, P. vivax is the commonest and most widely distributed, whereas P. falciparum causes the most deaths-about a million every year.,All these parasites enter their human host when an infected mosquito takes a blood meal.,The parasites migrate to the liver where they replicate and mature into a parasitic form known as merozoites.,After 8-9 days, the merozoites are released from the liver cells and invade red blood cells where they replicate rapidly before bursting out and infecting more red blood cells.,Malaria's recurring flu-like symptoms are caused by this cyclical increase in parasites in the blood.,Malaria needs to be treated promptly with antimalarial drugs to prevent the development of potentially fatal complications.,Infections with P. falciparum in particular can cause anemia (a reduction in red blood cell numbers) and can damage the brain and other vital organs by blocking the capillaries that supply these organs with blood.,It is unclear what proportion of anemia is attributable to non-falciparum malarias in regions of the world where several species of malaria parasite are always present (Plasmodium co-endemicity).,Public health officials in such regions need to know whether non-falciparum malarias are a major cause of anemia when designing malaria control strategies.,If P. vivax, for example, is a major cause of anemia in an area where P. vivax and P. falciparum co-exist, then any malaria control strategies that are implemented need to take into account the biological differences between the parasites.,In this hospital-based cohort study, the researchers investigate the burden of severe anemia from the endemic Plasmodium species in southern Papua, Indonesia.,The researchers used hospital record numbers to link clinical and laboratory data for patients presenting to a referral hospital in southern Papua over an 8-year period.,The hemoglobin level (an indicator of anemia) was measured in about a quarter of hospital presentations (some patients attended the hospital several times).,A third of the presentations who had their hemoglobin level determined (67,696 presentations) had clinical malaria.,Patients with P. malariae infection had the lowest average hemoglobin concentration.,Patients with mixed species, P. falciparum, and P. vivax infections had slightly higher average hemoglobin levels but all these levels were below the normal range for people living in Papua.,Among the patients who had their hemoglobin status assessed, 3.7% had severe anemia.,After allowing for other factors that alter the risk of anemia (“confounding” factors such as age), patients with mixed Plasmodium infection were more than three times as likely to have severe anemia as patients without malaria.,Patients with P. falciparum, P. vivax, or P. malariae infections were about twice as likely to have severe anemia as patients without malaria.,About 12.2% of severe anemia was attributable to non-falciparum infections, 15.1% was attributable to P. falciparum monoinfections, and P. vivax was the dominant cause of severe anemia in infancy.,Finally, compared to patients without anemia, patients with severe anemia had nearly a 6-fold higher risk of death.,These findings provide a comparative assessment of the pattern of anemia associated with non-falciparum malarias in Papua and an estimate of the public health importance of these malarias.,Although the accuracy of these findings may be affected by residual confounding (for example, the researchers did not consider nutritional status when calculating how much malaria infection increases the risk of anemia) and other limitations of the study design, non-falciparum malarias clearly make a major contribution to the burden of anemia in southern Papua.,In particular, these findings reveal the large contribution that P. vivax makes to severe anemia in infancy, show that the hematological (blood-related) impact of P. malariae is most apparent in adulthood, and suggest, in contrast to some previous reports, that mixed P. vivax/P. falciparum infection is associated with a higher risk of severe anemia than monoinfection with either species.,These findings, which need to be confirmed in other settings, highlight the public health importance of implementing integrated malaria control strategies that aim to control all Plasmodium species rather than a single species in regions of Plasmodium co-endemicity.,Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001575.,This study is further discussed in a PLOS Medicine Perspective by Gosling and Hsiang,Information is available from the World Health Organization on malaria (in several languages); the 2012 World Malaria Report provides details of the current global malaria situation,The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish), including information on different Plasmodium species and a selection of personal stories about malaria,The Malaria Vaccine Initiative has fact sheets on Plasmodium falciparum malaria and on Plasmodium vivax malaria,MedlinePlus provides links to additional information on malaria and on anemia (in English and Spanish),Information is available from the WorldWide Antimalarial Resistance Network on antimalarial drug resistance for P. falciparum and P. vivax

Amplicon deep sequencing permits sensitive detection of minority clones and improves discriminatory power for genotyping multi-clone Plasmodium falciparum infections.,New amplicon sequencing and data analysis protocols are needed for genotyping in epidemiological studies and drug efficacy trials of P. falciparum.,Targeted sequencing of molecular marker csp and novel marker cpmp was conducted in duplicate on mixtures of parasite culture strains and 37 field samples.,A protocol allowing to multiplex up to 384 samples in a single sequencing run was applied.,Software “HaplotypR” was developed for data analysis.,Cpmp was highly diverse (He = 0.96) in contrast to csp (He = 0.57).,Minority clones were robustly detected if their frequency was >1%.,False haplotype calls owing to sequencing errors were observed below that threshold.,To reliably detect haplotypes at very low frequencies, experiments are best performed in duplicate and should aim for coverage of >10′000 reads/amplicon.,When compared to length polymorphic marker msp2, highly multiplexed amplicon sequencing displayed greater sensitivity in detecting minority clones.,The online version of this article (10.1186/s12864-017-4260-y) contains supplementary material, which is available to authorized users.

Malaria is a major public health problem that is actively being addressed in a global eradication campaign.,Increased population mobility through international air travel has elevated the risk of re-introducing parasites to elimination areas and dispersing drug-resistant parasites to new regions.,A simple genetic marker that quickly and accurately identifies the geographic origin of infections would be a valuable public health tool for locating the source of imported outbreaks.,Here we analyse the mitochondrion and apicoplast genomes of 711 Plasmodium falciparum isolates from 14 countries, and find evidence that they are non-recombining and co-inherited.,The high degree of linkage produces a panel of relatively few single-nucleotide polymorphisms (SNPs) that is geographically informative.,We design a 23-SNP barcode that is highly predictive (~92%) and easily adapted to aid case management in the field and survey parasite migration worldwide.,Tracing the source of malarial infections is an important step towards monitoring and controlling the disease.,Here, Preston et al. analyse sequence data from 711 isolates and design a genetic barcode based on combined mitochondrial and apicoplast genomes that is able to distinguish between malaria parasites isolated from different geographical regions.

Malaria risk stratification is essential to differentiate areas with distinct malaria intensity and seasonality patterns.,The development of a simple prediction model to forecast malaria incidence by rainfall offers an opportunity for early detection of malaria epidemics.,To construct a national malaria stratification map, develop prediction models and forecast monthly malaria incidences based on rainfall data.,Using monthly malaria incidence data from 2012 to 2016, the district level malaria stratification was constructed by nonhierarchical clustering.,Cluster validity was examined by the maximum absolute coordinate change and analysis of variance (ANOVA) with a conservative post hoc test (Bonferroni) as the multiple comparison test.,Autocorrelation and cross-correlation analyses were performed to detect the autocorrelation of malaria incidence and the lagged effect of rainfall on malaria incidence.,The effect of rainfall on malaria incidence was assessed using seasonal autoregressive integrated moving average (SARIMA) models.,Ljung-Box statistics for model diagnosis and stationary R-squared and Normalized Bayesian Information Criteria for model fit were used.,Model validity was assessed by analyzing the observed and predicted incidences using the spearman correlation coefficient and paired samples t-test.,A four cluster map (high risk, moderate risk, low risk, and very low risk) was the most valid stratification system for the reported malaria incidence in Eritrea.,Monthly incidences were influenced by incidence rates in the previous months.,Monthly incidence of malaria in the constructed clusters was associated with 1, 2, 3, and 4 lagged months of rainfall.,The constructed models had acceptable accuracy as 73.1%, 46.3%, 53.4%, and 50.7% of the variance in malaria transmission were explained by rainfall in the high-risk, moderate-risk, low-risk, and very low-risk clusters, respectively.,Change in rainfall patterns affect malaria incidence in Eritrea.,Using routine malaria case reports and rainfall data, malaria incidences can be forecasted with acceptable accuracy.,Further research should consider a village or health facility level modeling of malaria incidence by including other climatic factors like temperature and relative humidity.

Malaria is one of the primary health concerns in Madagascar.,Based on the duration and intensity of transmission, Madagascar is divided into five epidemiological strata that range from low to mesoendemic transmission.,In this study, the spatial and temporal dynamics of malaria within each epidemiological zone were studied.,The number of reported cases of uncomplicated malaria from 112 health districts between 2010 and 2014 were compiled and analysed.,First, a Standardized Incidence Ratio was calculated to detect districts with anomalous incidence compared to the stratum-level incidence.,Building on this, spatial and temporal malaria clusters were identified throughout the country and their variability across zones and over time was analysed.,The incidence of malaria increased from 2010 to 2014 within each stratum.,A basic analysis showed that districts with more than 50 cases per 1000 inhabitants are mainly located in two strata: East and West.,Lower incidence values were found in the Highlands and Fringe zones.,The standardization method revealed that the number of districts with a higher than expected numbers of cases increased through time and expanded into the Highlands and Fringe zones.,The cluster analysis showed that for the endemic coastal region, clusters of districts migrated southward and the incidence of malaria was the highest between January and July with some variation within strata.,This study identified critical districts with low incidence that shifted to high incidence and district that were consistent clusters across each year.,The current study provided a detailed description of changes in malaria epidemiology and can aid the national malaria programme to reduce and prevent the expansion of the disease by targeting the appropriate areas.,The online version of this article (10.1186/s12936-018-2206-8) contains supplementary material, which is available to authorized users.

Malaria among school children is increasingly receiving attention, yet the burden of malaria in this age group is poorly defined.,This study presents data on malaria morbidity among school children in Bungoma county, western Kenya.,This study investigated the burden and risk factors of Plasmodium falciparum infection, clinical malaria, and anaemia among 2346 school children aged 5-15 years, who were enrolled in an individually randomized trial evaluating the effect of anthelmintic treatment on the risks of malaria.,At baseline, children were assessed for anaemia and nutritional status and information on household characteristics was collected.,Children were followed-up for 13 months to assess the incidence of clinical malaria by active detection, and P. falciparum infection and density evaluated using repeated cross-sectional surveys over 15 months.,On average prevalence of P. falciparum infection was 42 % and ranged between 32 and 48 % during the five cross-sectional surveys.,Plasmodium falciparum prevalence was significantly higher among boys than girls.,The overall incidence of clinical malaria was 0.26 episodes per person year (95 % confidence interval, 0.24-0.29) and was significantly higher among girls (0.23 versus 0.31, episodes per person years).,Both infection prevalence and clinical disease varied by season.,In multivariable analysis, P. falciparum infection was associated with being male, lower socioeconomic status and stunting.,The risk of clinical malaria was associated with being female.,These findings show that the burden of P. falciparum parasitaemia, clinical malaria and anaemia among school children is not insignificant, and suggest that malaria control programmes should be expanded to include this age group.,The online version of this article (doi:10.1186/s12936-016-1176-y) contains supplementary material, which is available to authorized users.

Sub-microscopic (SM) Plasmodium infections represent transmission reservoirs that could jeopardise malaria elimination goals.,A better understanding of the epidemiology of these infections and factors contributing to their occurrence will inform effective elimination strategies.,While the epidemiology of SM P. falciparum infections has been documented, that of SM P. vivax infections has not been summarised.,The objective of this study is to address this deficiency.,A systematic search of PubMed was conducted, and results of both light microscopy (LM) and polymerase chain reaction (PCR)-based diagnostic tests for P. vivax from 44 cross-sectional surveys or screening studies of clinical malaria suspects were analysed.,Analysis revealed that SM P. vivax is prevalent across different geographic areas with varying transmission intensities.,On average, the prevalence of SM P. vivax in cross-sectional surveys was 10.9%, constituting 67.0% of all P. vivax infections detected by PCR.,The relative proportion of SM P. vivax is significantly higher than that of the sympatric P. falciparum in these settings.,A positive relationship exists between PCR and LM P. vivax prevalence, while there is a negative relationship between the proportion of SM P. vivax and the LM prevalence for P. vivax.,Amongst clinical malaria suspects, however, SM P. vivax was not identified.,SM P. vivax is prevalent across different geographic areas, particularly areas with relatively low transmission intensity.,Diagnostic tools with sensitivity greater than that of LM are required for detecting these infection reservoirs.,In contrast, SM P. vivax is not prevalent in clinical malaria suspects, supporting the recommended use of quality LM and rapid diagnostic tests in clinical case management.,These findings enable malaria control and elimination programs to estimate the prevalence and proportion of SM P. vivax infections in their settings, and develop appropriate elimination strategies to tackle SM P. vivax to interrupt transmission.

Seasonal migrant and permanent laborers who are working in big mechanized agricultural farms in Metema - Humera lowlands are not included in Ethiopia Malaria Elimination Program.,The aim of this research was to show the high confirmed and treated malaria cases in these laborers.,A retrospective analysis of the confirmed and treated malaria cases in all the districts of West, Central and North Gondar Zones, using Weekly Public Health Emergency Management (PHEM) reports, was conducted to show a complete picture of the malaria incidences in the areas.,A total of 3,485,646 confirmed malaria cases were treated in Amhara region during 2013 to 2017.,Of the total malaria cases in the Amhara region during these period, 1, 286, 848 cases or 37.2% were originated from West, Central and North Gondar Zones.,But these 3 Zones contribute only 17% of Amhara region population.,Of all the confirmed malaria cases reported in the 3 Zones, 41.7% (536,749/1286, 848) was reported from the three lowland districts (Metema, West Armachiho and Quara) of the West Gondar Zone during the same study period.,But, the West Gondar Zone has only around 10% of the population in these three zones.,The highest annual parasite incidence for malaria was found in West Armachiho district.,Majority of above 14 years malaria cases in West Gondar zone were found from laborers.,Migrant and permanent laborers working in mechanized agricultural fields in Metema - Humera lowlands are highly exposed to malaria and immediate interventions are required.

Sub-microscopic and asymptomatic infections could be bottlenecks to malaria elimination efforts in Ethiopia.,This study determined the prevalence of malaria, and individual and household-level factors associated with Plasmodium infections obtained following detection of index cases in health facilities in Jimma Zone.,Index malaria cases were passively detected and tracked in health facilities from June to November 2016.,Moreover, family members of the index houses and neighbours located within approximately 200 m from the index houses were also screened for malaria.,A total of 39 index cases initiated the reactive case detection of 726 individuals in 116 households.,Overall, the prevalence of malaria using microscopy and PCR was 4.0% and 8.96%, respectively.,Seventeen (43.6%) of the index cases were from Doyo Yaya kebele, where parasite prevalence was higher.,The majority of the malaria cases (90.74%) were asymptomatic.,Fever (AOR = 12.68, 95% CI 3.34-48.18) and history of malaria in the preceding 1 year (AOR = 3.62, 95% CI 1.77-7.38) were significant individual-level factors associated with detection of Plasmodium infection.,Moreover, living in index house (AOR = 2.22, 95% CI 1.16-4.27), house with eave (AOR = 2.28, 95% CI 1.14-4.55), area of residence (AOR = 6.81, 95% CI 2.49-18.63) and family size (AOR = 3.35, 95% CI 1.53-7.33) were main household-level predictors for residual malaria transmission.,The number of index cases per kebele may enhance RACD efforts to detect additional malaria cases in low transmission settings.,Asymptomatic and sub-microscopic infections were high in the study area, which need new or improved surveillance tools for malaria elimination efforts.

Post-kala-azar dermal leishmaniasis (PKDL) is a common complication of visceral leishmaniasis (VL) caused by Leishmania donovani.,Because of its possible role in transmission it is considered a public health problem in VL endemic areas.,The clinical features include a skin rash consisting of macules, papules or nodules in an otherwise healthy individual; this presentation is determined by the immune response towards parasites in the skin that probably persisted from the previous VL episode.,The immune response in VL, cured VL and PKDL is the result of changes in the cytokine profile that only in part can be captured under the Th1 and Th2 dichotomy.,Regulatory T cells and Th 17 cells also play a role.,VL is characterized by an absent immune response to Leishmania with a predominantly Th2 type of response with high levels of IL-10; after successful treatment the patient will be immune with in vitro features of a Th1 type of response and in vivo a positive leishmanin skin test.,PKDL takes an intermediate position with a dissociation of the immune response between the skin and the viscera, with a Th2 and Th1 type of response, respectively.,It is likely that immune responses determine the different epidemiological and clinical characteristics of PKDL in Asia and Africa; various risk factors for PKDL may influence this, such as incomplete and inadequate treatment of VL, parasite resistance and genetic factors.,It should be noted that PKDL is a heterogeneous and dynamic condition and patients differ with regard to time of onset after visceral leishmaniasis (VL), chronicity, extent and appearance of the rash including related immune responses, all of which may vary over time.,Better understanding of these immune responses may offer opportunities for manipulation including combined chemotherapy and immunotherapy for VL to prevent PKDL from occurring and similarly in the treatment of chronic or treatment resistant PKDL cases.

There is an urgent requirement for safe, oral and cost-effective drugs for the treatment of visceral leishmaniasis (VL).,We report that delamanid (OPC-67683), an approved drug for multi-drug resistant tuberculosis, is a potent inhibitor of Leishmania donovani both in vitro and in vivo.,Twice-daily oral dosing of delamanid at 30 mg kg-1 for 5 days resulted in sterile cures in a mouse model of VL.,Treatment with lower doses revealed a U-shaped (hormetic) dose-response curve with greater parasite suppression at 1 mg kg-1 than at 3 mg kg-1 (5 or 10 day dosing).,Dosing delamanid for 10 days confirmed the hormetic dose-response and improved the efficacy at all doses investigated.,Mechanistic studies reveal that delamanid is rapidly metabolised by parasites via an enzyme, distinct from the nitroreductase that activates fexinidazole.,Delamanid has the potential to be repurposed as a much-needed oral therapy for VL.,DOI:http://dx.doi.org/10.7554/eLife.09744.001,Better, safer, oral drugs are desperately needed for the treatment of visceral leishmaniasis, a parasitic infectious disease that causes an estimated 40,000 deaths a year, predominantly in South America, East Africa and the Indian subcontinent.,The parasite that causes visceral leishmaniasis is transmitted between individuals by blood-sucking sandflies, and there are currently no vaccines that protect against the disease.,In addition, all currently available drug treatments have serious limitations - they are expensive, toxic, have to be applied over a long period of time (mainly by injection) and may become ineffective as the parasites adapt to resist the drug.,A cost-effective way to find a new treatment for a disease is to repurpose existing clinically approved drugs that are used to treat other diseases.,Patterson, Wyllie et al. now report that a drug called delamanid, which was recently approved for the treatment of tuberculosis, can cure visceral leishmaniasis in mice.,The drug worked when applied orally at doses that might be achievable in human patients, and can also kill parasites obtained from human patients.,Patterson, Wyllie et al. also provide evidence that suggests that delamanid is processed in the parasites by an unknown enzyme.,However, this enzyme is not the one that activates a different class of drugs that are used to treat visceral leishmaniasis.,Future studies now need to identify the enzyme that is targeted by delamanid, and could investigate combinations of drugs that slow the emergence of resistant parasites and improve delamanid’s safety and effectiveness.,Clinical trials are required to test how well delamanid treats visceral leishmaniasis in humans.,DOI:http://dx.doi.org/10.7554/eLife.09744.002

Virulence of the most deadly malaria parasite Plasmodium falciparum is linked to the variant surface antigen PfEMP1, which is encoded by about 60 var genes per parasite genome.,Although the expression of particular variants has been associated with different clinical outcomes, little is known about var gene expression at the onset of infection.,By analyzing controlled human malaria infections via quantitative real-time PCR, we show that parasite populations from 18 volunteers expressed virtually identical transcript patterns that were dominated by the subtelomeric var gene group B and, to a lesser extent, group A.,Furthermore, major changes in composition and frequency of var gene transcripts were detected between the parental parasite culture that was used to infect mosquitoes and Plasmodia recovered from infected volunteers, suggesting that P. falciparum resets its var gene expression during mosquito passage and starts with the broad expression of a specific subset of var genes when entering the human blood phase.

Malaria parasites elude eradication attempts both within the human host and across nations.,At the individual level, parasites evade the host immune responses through antigenic variation.,At the global level, parasites escape drug pressure through single nucleotide variants and gene copy amplification events conferring drug resistance.,Despite their importance to global health, the rates at which these genomic alterations emerge have not been determined.,We studied the complete genomes of different Plasmodium falciparum clones that had been propagated asexually over one year in the presence and absence of drug pressure.,A combination of whole-genome microarray analysis and next-generation deep resequencing (totaling 14 terabases) revealed a stable core genome with only 38 novel single nucleotide variants appearing in seventeen evolved clones (avg.,5.4 per clone).,In clones exposed to atovaquone, we found cytochrome b mutations as well as an amplification event encompassing the P. falciparum multidrug resistance associated protein (mrp1) on chromosome 1.,We observed 18 large-scale (>1 kb on average) deletions of telomere-proximal regions encoding multigene families, involved in immune evasion (9.5×10−6 structural variants per base pair per generation).,Six of these deletions were associated with chromosomal crossovers generated during mitosis.,We found only minor differences in rates between genetically distinct strains and between parasites cultured in the presence or absence of drug.,Using these derived mutation rates for P. falciparum (1.0-9.7×10−9 mutations per base pair per generation), we can now model the frequency at which drug or immune resistance alleles will emerge under a well-defined set of assumptions.,Further, the detection of mitotic recombination events in var gene families illustrates how multigene families can arise and change over time in P. falciparum.,These results will help improve our understanding of how P. falciparum evolves to evade control efforts within both the individual hosts and large populations.

Background: Prompt and effective case detection and treatment are vital components of the malaria case management strategy as malaria-endemic countries implement the testing, treating and tracking policy.,The implementation of this policy in public and formal private sectors continue to receive great attention while the informal private retail sector (mostly the patent and propriety medicine vendors [PPMVs]) where about 60% of patients with fever in Nigeria seek treatment is yet to be fully integrated.,The PPMVs sell artemisinin combination therapies (ACTs) without prior testing and are highly patronized.,Without prior testing, malaria is likely to be over-treated.,The need to expand access to diagnosis in the huge informal private health sector among PPMVs is currently being explored to ensure that clients that patronize retail drug stores are tested before sales of ACTs.,Methods: A cross-sectional multistage study was conducted among 1279 adult clients, 20 years and above, who purchased malaria medicines from 119 selected PPMVs in five administrative areas (States) of Nigeria, namely: Adamawa, Cross River, Enugu, Lagos and Kaduna, as well as the Federal Capital Territory, Abuja.,Exit interviews using a standard case report questionnaire was conducted after the purchase of the antimalarial medicine and thick/thin blood smears from the clients’ finger-prick were prepared to confirm malaria by expert microscopy.,Results: Of the 1279 clients who purchased malaria medicines from the PPMV outlets, 107 (8.4%) were confirmed to have malaria parasites.,The malaria prevalence in the various study areas ranged from 3.5% to 16%.,A high proportion of clients in the various study sites who had no need for malaria medicines (84%-96.5%) purchased and used antimalarial medicines from the PPMVs.,This indicated a high level of over-treatment and misuse of antimalarials.,Common symptoms that are widely used as indicators for malaria such as, fever, headache, and tiredness were not significantly associated with malaria.,Nausea/vomiting, poor appetite, chills, bitter taste in the mouth and dark urine were symptoms that were significantly associated with malaria among the adult clients (P<.05) but not fever (P=.06).,Conclusion: Misuse of ACTs following overtreatment of malaria based on clinical diagnosis occurs when suspected cases of malaria are not prior confirmed with a test.,Non-testing before sales of malaria medicines by PPMVs will perpetuate ACT misuse with the patients not benefiting due to poor treatment outcomes, waste of medicines and financial loss from out-of-pocket payment for unneeded medicines.

Since 2010, the World Health Organization has been recommending that all suspected cases of malaria be confirmed with parasite-based diagnosis before treatment.,These guidelines represent a paradigm shift away from presumptive antimalarial treatment of fever.,Malaria rapid diagnostic tests (mRDTs) are central to implementing this policy, intended to target artemisinin-based combination therapies (ACT) to patients with confirmed malaria and to improve management of patients with nonmalarial fevers.,The ACT Consortium conducted ten linked studies, eight in sub-Saharan Africa and two in Afghanistan, to evaluate the impact of mRDT introduction on case management across settings that vary in malaria endemicity and healthcare provider type.,This synthesis includes 562,368 outpatient encounters (study size range 2,400-432,513). mRDTs were associated with significantly lower ACT prescription (range 8-69% versus 20-100%).,Prescribing did not always adhere to malaria test results; in several settings, ACTs were prescribed to more than 30% of test-negative patients or to fewer than 80% of test-positive patients.,Either an antimalarial or an antibiotic was prescribed for more than 75% of patients across most settings; lower antimalarial prescription for malaria test-negative patients was partly offset by higher antibiotic prescription.,Symptomatic management with antipyretics alone was prescribed for fewer than 25% of patients across all scenarios.,In community health worker and private retailer settings, mRDTs increased referral of patients to other providers.,This synthesis provides an overview of shifts in case management that may be expected with mRDT introduction and highlights areas of focus to improve design and implementation of future case management programs.

Scale-up of malaria prevention and treatment needs to continue but national strategies and budget allocations are not always evidence-based.,This article presents a new modelling tool projecting malaria infection, cases and deaths to support impact evaluation, target setting and strategic planning.,Nested in the Spectrum suite of programme planning tools, the model includes historic estimates of case incidence and deaths in groups aged up to 4, 5-14, and 15+ years, and prevalence of Plasmodium falciparum infection (PfPR) among children 2-9 years, for 43 sub-Saharan African countries and their 602 provinces, from the WHO and malaria atlas project.,Impacts over 2016-2030 are projected for insecticide-treated nets (ITNs), indoor residual spraying (IRS), seasonal malaria chemoprevention (SMC), and effective management of uncomplicated cases (CMU) and severe cases (CMS), using statistical functions fitted to proportional burden reductions simulated in the P. falciparum dynamic transmission model OpenMalaria.,In projections for Nigeria, ITNs, IRS, CMU, and CMS scale-up reduced health burdens in all age groups, with largest proportional and especially absolute reductions in children up to 4 years old.,Impacts increased from 8 to 10 years following scale-up, reflecting dynamic effects.,For scale-up of each intervention to 80% effective coverage, CMU had the largest impacts across all health outcomes, followed by ITNs and IRS; CMS and SMC conferred additional small but rapid mortality impacts.,Spectrum-Malaria’s user-friendly interface and intuitive display of baseline data and scenario projections holds promise to facilitate capacity building and policy dialogue in malaria programme prioritization.,The module’s linking to the OneHealth Tool for costing will support use of the software for strategic budget allocation.,In settings with moderately low coverage levels, such as Nigeria, improving case management and achieving universal coverage with ITNs could achieve considerable burden reductions.,Projections remain to be refined and validated with local expert input data and actual policy scenarios.,The online version of this article (doi:10.1186/s12936-017-1705-3) contains supplementary material, which is available to authorized users.

The phase 3 trial of the RTS,S/AS01 malaria vaccine candidate showed modest efficacy of the vaccine against Plasmodium falciparum malaria, but was not powered to assess mortality endpoints.,Impact projections and cost-effectiveness estimates for longer timeframes than the trial follow-up and across a range of settings are needed to inform policy recommendations.,We aimed to assess the public health impact and cost-effectiveness of routine use of the RTS,S/AS01 vaccine in African settings.,We compared four malaria transmission models and their predictions to assess vaccine cost-effectiveness and impact.,We used trial data for follow-up of 32 months or longer to parameterise vaccine protection in the group aged 5-17 months.,Estimates of cases, deaths, and disability-adjusted life-years (DALYs) averted were calculated over a 15 year time horizon for a range of levels of Plasmodium falciparum parasite prevalence in 2-10 year olds (PfPR2-10; range 3-65%).,We considered two vaccine schedules: three doses at ages 6, 7·5, and 9 months (three-dose schedule, 90% coverage) and including a fourth dose at age 27 months (four-dose schedule, 72% coverage).,We estimated cost-effectiveness in the presence of existing malaria interventions for vaccine prices of US$2-10 per dose.,In regions with a PfPR2-10 of 10-65%, RTS,S/AS01 is predicted to avert a median of 93 940 (range 20 490-126 540) clinical cases and 394 (127-708) deaths for the three-dose schedule, or 116 480 (31 450-160 410) clinical cases and 484 (189-859) deaths for the four-dose schedule, per 100 000 fully vaccinated children.,A positive impact is also predicted at a PfPR2-10 of 5-10%, but there is little impact at a prevalence of lower than 3%.,At $5 per dose and a PfPR2-10 of 10-65%, we estimated a median incremental cost-effectiveness ratio compared with current interventions of $30 (range 18-211) per clinical case averted and $80 (44-279) per DALY averted for the three-dose schedule, and of $25 (16-222) and $87 (48-244), respectively, for the four-dose schedule.,Higher ICERs were estimated at low PfPR2-10 levels.,We predict a significant public health impact and high cost-effectiveness of the RTS,S/AS01 vaccine across a wide range of settings.,Decisions about implementation will need to consider levels of malaria burden, the cost-effectiveness and coverage of other malaria interventions, health priorities, financing, and the capacity of the health system to deliver the vaccine.,PATH Malaria Vaccine Initiative; Bill & Melinda Gates Foundation; Global Good Fund; Medical Research Council; UK Department for International Development; GAVI, the Vaccine Alliance; WHO.

Erythrocyte polymorphisms associated with a survival advantage to Plasmodium falciparum infection have undergone positive selection.,There is a predominance of blood group O in malaria-endemic regions, and several lines of evidence suggest that ABO blood groups may influence the outcome of P. falciparum infection.,Based on the hypothesis that enhanced innate clearance of infected polymorphic erythrocytes is associated with protection from severe malaria, we investigated whether P. falciparum-infected O erythrocytes are more efficiently cleared by macrophages than infected A and B erythrocytes.,We show that human macrophages in vitro and mouse monocytes in vivo phagocytose P. falciparum-infected O erythrocytes more avidly than infected A and B erythrocytes and that uptake is associated with increased hemichrome deposition and high molecular weight band 3 aggregates in infected O erythrocytes.,Using infected A1, A2, and O erythrocytes, we demonstrate an inverse association of phagocytic capacity with the amount of A antigen on the surface of infected erythrocytes.,Finally, we report that enzymatic conversion of B erythrocytes to type as O before infection significantly enhances their uptake by macrophages to observed level comparable to that with infected O wild-type erythrocytes.,These data provide the first evidence that ABO blood group antigens influence macrophage clearance of P. falciparum-infected erythrocytes and suggest an additional mechanism by which blood group O may confer resistance to severe malaria.

Infection with Plasmodium falciparum during pregnancy contributes substantially to the disease burden in both mothers and offspring.,Placental malaria may lead to intrauterine growth restriction or preterm delivery resulting in low birth weight (LBW), which, in general, is associated with increased infant morbidity and mortality.,However, little is known about the possible direct impact of the specific disease processes occurring in PM on longer term outcomes such as subsequent retarded growth development independent of LBW.,In an existing West-African cohort, 783 healthy infants with a birth weight of at least 2,000 g were followed up during their first year of life.,The aim of the study was to investigate if Plasmodium falciparum infection of the placenta, assessed by placental histology, has an impact on several anthropometric parameters, measured at birth and after three, six and 12 months using generalized estimating equations models adjusting for moderate low birth weight.,Independent of LBW, first to third born infants who were exposed to either past, chronic or acute placental malaria during pregnancy had significantly lower weight-for-age (-0.43, 95% CI: -0.80;-0.07), weight-for-length (-0.47, 95% CI: -0.84; -0.10) and BMI-for-age z-scores (-0.57, 95% CI: -0.84; -0.10) compared to infants born to mothers who were not diagnosed with placental malaria (p = 0.019, 0.013, and 0.012, respectively).,Interestingly, the longitudinal data on histology-based diagnosis of PM also document a sharp decline of PM prevalence in the Sukuta cohort from 16.5% in 2002 to 5.4% in 2004.,It was demonstrated that PM has a negative impact on the infant's subsequent weight development that is independent of LBW, suggesting that the longer term effects of PM have been underestimated, even in areas where malaria transmission is declining.

A meeting sponsored by the Bill & Melinda Gates Foundation was held at the Avanti Hotel, Mohammedia, Morocco, July 14-15, 2015.,The meeting resulted in the formation of the Cattle Tick Vaccine Consortium (CATVAC).

We have previously evaluated the vaccine efficacies of seven tetraspanins of Echinococcus multilocularis (Em-TSP1-7) against alveolar echinococcosis (AE) by subcutaneous (s.c.) administration with Freund's adjuvant.,Over 85% of liver cyst lesion number reductions (CLNR) were achieved by recombinant Em-TSP1 (rEm-TSP1) and -TSP3 (rEm-TSP3).,However, to develop an efficient and safe human vaccine, the efficacy of TSP mucosal vaccines must be thoroughly evaluated.,rEm-TSP1 and -TSP3 along with nontoxic CpG ODN (CpG oligodeoxynucleotides) adjuvant were intranasally (i.n.) immunized to BALB/c mice and their vaccine efficacies were evaluated by counting liver CLNR (experiment I).,37.1% (p<0.05) and 62.1% (p<0.001) of CLNR were achieved by these two proteins, respectively.,To study the protection-associated immune responses induced by rEm-TSP3 via different immunization routes (i.n. administration with CpG or s.c. immunization with Freund's adjuvant), the systemic and mucosal antibody responses were detected by ELISA (experiment II).,S.c. and i.n. administration of rEm-TSP3 achieved 81.9% (p<0.001) and 62.8% (p<0.01) CLNR in the liver, respectively.,Both the immunization routes evoked strong serum IgG, IgG1 and IgG2α responses; i.n. immunization induced significantly higher IgA responses in nasal cavity and intestine compared with s.c. immunization (p<0.001).,Both immunization routes induced extremely strong liver IgA antibody responses (p<0.001).,The Th1 and Th2 cell responses were assessed by examining the IgG1/IgG2α ratio at two and three weeks post-immunization.,S.c. immunization resulted in a reduction in the IgG1/IgG2α ratio (Th1 tendency), whereas i.n. immunization caused a shift from Th1 to Th2.,Moreover, immunohistochemistry showed that Em-TSP1 and -TSP3 were extensively located on the surface of E. multilocularis cysts, protoscoleces and adult worms with additional expression of Em-TSP3 in the inner part of protoscoleces and oncospheres.,Our study indicated that i.n. administration of rEm-TSP3 with CpG is able to induce both systemic and local immune responses and thus provides significant protection against AE.

Long-lasting insecticidal nets (LLINs) have contributed to the reduction of malaria in sub-Saharan Africa, including Tanzania.,However, they rely on daily user behaviour and high coverage which is difficult to maintain.,Also, insecticide resistance among malaria vector mosquitoes is contributing to reduced efficacy of control tools.,To overcome these problems, we propose to evaluate a new tool for house modification, the insecticide-treated eave nets (ITENs) in combination with insecticide-treated window screens (ITWS) incorporated with dual active ingredient (dual AI) for the control of malaria.,Four hundred and fifty (450) households with intact walls, open eaves without screens or nets on the windows in Chalinze district will be eligible and recruited upon written informed consent.,The households will be randomly allocated into two arms: one with ITENs and ITWS installed and the other without.,Malaria parasite detection using a quantitative polymerase chain reaction (qPCR) will be conducted shortly after the long rain (June/July, 2022) as the primary outcome and shortly after the short rain (January/February, 2022) as the secondary outcome.,Other secondary outcomes include clinical malaria cases, and density of malaria vectors and nuisance after the short rain and long rain.,In addition, surveys will be conducted in households with ITENs and ITWS to estimate the intervention’s cost during installation, adverse effects one month after installation, and presence, fabric integrity and user acceptance six and twelve months after installation.,Bioefficacy and chemical content will be evaluated twelve months after installation.,ITENs and ITWS have been shown in Kenya to reduce indoor mosquito density.,However, it is not known if indoor mosquito density reduction translates into reduction of malaria cases.,Data from the study will measure the potential public health value of an additional intervention for malaria control at the household level in areas of mosquito insecticide resistance that does not require daily adherence.,The study is registered on ClinicalTrials.gov.,The online version contains supplementary material available at 10.1186/s13063-022-06408-4.

The global malaria burden has fallen since 2000, sometimes before large-scale vector control programmes were initiated.,While long-lasting insecticide-treated nets and indoor residual spraying are highly effective interventions, this study tests the hypothesis that improved housing can reduce malaria by decreasing house entry by malaria mosquitoes.,A systematic review and meta-analysis was conducted to assess whether modern housing is associated with a lower risk of malaria than traditional housing, across all age groups and malaria-endemic settings.,Six electronic databases were searched to identify intervention and observational studies published from 1 January, 1900 to 13 December, 2013, measuring the association between house design and malaria.,The primary outcome measures were parasite prevalence and incidence of clinical malaria.,Crude and adjusted effects were combined in fixed- and random-effects meta-analyses, with sub-group analyses for: overall house type (traditional versus modern housing); screening; main wall, roof and floor materials; eave type; ceilings and elevation.,Of 15,526 studies screened, 90 were included in a qualitative synthesis and 53 reported epidemiological outcomes, included in a meta-analysis.,Of these, 39 (74 %) showed trends towards a lower risk of epidemiological outcomes associated with improved house features.,Of studies assessing the relationship between modern housing and malaria infection (n = 11) and clinical malaria (n = 5), all were observational, with very low to low quality evidence.,Residents of modern houses had 47 % lower odds of malaria infection compared to traditional houses (adjusted odds ratio (OR) 0°53, 95 % confidence intervals (CI) 0°42-0°67, p < 0°001, five studies) and a 45-65 % lower odds of clinical malaria (case-control studies: adjusted OR 0°35, 95 % CI 0°20-0°62, p <0°001, one study; cohort studies: adjusted rate ratio 0°55, 95 % CI 0°36-0°84, p = 0°005, three studies).,Evidence of a high risk of bias was found within studies.,Despite low quality evidence, the direction and consistency of effects indicate that housing is an important risk factor for malaria.,Future research should evaluate the protective effect of specific house features and incremental housing improvements associated with socio-economic development.,The online version of this article (doi:10.1186/s12936-015-0724-1) contains supplementary material, which is available to authorized users.

Where malaria endemicity is low, control programmes need increasingly sensitive tools for monitoring malaria transmission intensity (MTI) and to better define health priorities.,A cross-sectional survey was conducted in a low endemicity area of the Peruvian north-western coast to assess the MTI using both molecular and serological tools.,Epidemiological, parasitological and serological data were collected from 2,667 individuals in three settlements of Bellavista district, in May 2010.,Parasite infection was detected using microscopy and polymerase chain reaction (PCR).,Antibodies to Plasmodium vivax merozoite surface protein-119 (PvMSP119) and to Plasmodium falciparum glutamate-rich protein (PfGLURP) were detected by ELISA.,Risk factors for exposure to malaria (seropositivity) were assessed by multivariate survey logistic regression models.,Age-specific antibody prevalence of both P. falciparum and P. vivax were analysed using a previously published catalytic conversion model based on maximum likelihood for generating seroconversion rates (SCR).,The overall parasite prevalence by microscopy and PCR were extremely low: 0.3 and 0.9%, respectively for P. vivax, and 0 and 0.04%, respectively for P. falciparum, while seroprevalence was much higher, 13.6% for P. vivax and 9.8% for P. falciparum.,Settlement, age and occupation as moto-taxi driver during previous year were significantly associated with P. falciparum exposure, while age and distance to the water drain were associated with P. vivax exposure.,Likelihood ratio tests supported age seroprevalence curves with two SCR for both P. vivax and P. falciparum indicating significant changes in the MTI over time.,The SCR for PfGLURP was 19-fold lower after 2002 as compared to before (λ1 = 0.022 versus λ2 = 0.431), and the SCR for PvMSP119 was four-fold higher after 2006 as compared to before (λ1 = 0.024 versus λ2 = 0.006).,Combining molecular and serological tools considerably enhanced the capacity of detecting current and past exposure to malaria infections and related risks factors in this very low endemicity area.,This allowed for an improved characterization of the current human reservoir of infections, largely hidden and heterogeneous, as well as providing insights into recent changes in species specific MTIs.,This approach will be of key importance for evaluating and monitoring future malaria elimination strategies.

The study area in Rondônia was the site of extensive malaria epidemic outbreaks in the 19th and 20th centuries related to environmental impacts, with large immigration flows.,The present work analyzes the transmission dynamics of malaria in these areas to propose measures for avoiding epidemic outbreaks due to the construction of two Hydroelectric Power Plants.,A population based baseline demographic census and a malaria prevalence follow up were performed in two river side localities in the suburbs of Porto Velho city and in its rural vicinity.,The quantification and nature of malaria parasites in clinical patients and asymptomatic parasite carriers were performed using microscopic and Real Time PCR methodologies.,Anopheles densities and their seasonal variation were done by monthly captures for defining HBR (hourly biting rate) values.,Main results: (i) malaria among residents show the riverside profile, with population at risk represented by children and young adults; (ii) asymptomatic vivax and falciparum malaria parasite carriers correspond to around 15% of adults living in the area; (iii) vivax malaria relapses were responsible for 30% of clinical cases; (iv) malaria risk for the residents was evaluated as 20-25% for vivax and 5-7% for falciparum malaria; (v) anopheline densities shown outdoors HBR values 5 to 10 fold higher than indoors and reach 10.000 bites/person/year; (vi) very high incidence observed in one of the surveyed localities was explained by a micro epidemic outbreak affecting visitors and temporary residents.,Temporary residents living in tents or shacks are accessible to outdoors transmission.,Seasonal fishermen were the main group at risk in the study and were responsible for a 2.6 fold increase in the malaria incidence in the locality.,This situation illustrates the danger of extensive epidemic outbreaks when thousands of workers and secondary immigrant population will arrive attracted by opportunities opened by the Hydroelectric Power Plants constructions.