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Certain species of macaques are natural hosts of Plasmodium knowlesi and Plasmodium cynomolgi, which can both cause malaria in humans, and Plasmodium inui, which can be experimentally transmitted to humans.,A significant number of zoonotic malaria cases have been reported in humans throughout Southeast Asia, including Thailand.,There have been only two studies undertaken in Thailand to identify malaria parasites in non-human primates in 6 provinces.,The objective of this study was to determine the prevalence of P. knowlesi, P. cynomolgi, P. inui, Plasmodium coatneyi and Plasmodium fieldi in non-human primates from 4 new locations in Thailand.,A total of 93 blood samples from Macaca fascicularis, Macaca leonina and Macaca arctoides were collected from four locations in Thailand: 32 were captive M. fascicularis from Chachoengsao Province (CHA), 4 were wild M. fascicularis from Ranong Province (RAN), 32 were wild M. arctoides from Prachuap Kiri Khan Province (PRA), and 25 were wild M. leonina from Nakornratchasima Province (NAK).,DNA was extracted from these samples and analysed by nested PCR assays to detect Plasmodium, and subsequently to detect P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi.,Twenty-seven of the 93 (29%) samples were Plasmodium-positive by nested PCR assays.,Among wild macaques, all 4 M. fascicularis at RAN were infected with malaria parasites followed by 50% of 32 M. arctoides at PRA and 20% of 25 M. leonina at NAK.,Only 2 (6.3%) of the 32 captive M. fascicularis at CHA were malaria-positive.,All 5 species of Plasmodium were detected and 16 (59.3%) of the 27 macaques had single infections, 9 had double and 2 had triple infections.,The composition of Plasmodium species in macaques at each sampling site was different.,Macaca arctoides from PRA were infected with P. knowlesi, P. coatneyi, P. cynomolgi, P. inui and P. fieldi.,The prevalence and species of Plasmodium varied among the wild and captive macaques, and between macaques at 4 sampling sites in Thailand.,Macaca arctoides is a new natural host for P. knowlesi, P. inui, P. coatneyi and P. fieldi.

Malaria remains one of the most significant global public health burdens, with nearly half of the world's population at risk of infection.,Malaria is not however a monolithic disease - it can be caused by multiple different parasite species of the Plasmodium genus, each of which can induce different symptoms and pathology, and which pose quite different challenges for control.,Furthermore, malaria is in no way restricted to humans.,There are Plasmodium species that have adapted to infect most warm-blooded vertebrate species, and the genus as a whole is both highly successful and highly diverse.,How, where and when human malaria parasites originated from within this diversity has long been a subject of fascination and sometimes also controversy.,The past decade has seen the publication of a number of important discoveries about malaria parasite origins, all based on the application of molecular diagnostic tools to new sources of samples.,This review summarizes some of those recent discoveries and discusses their implication for our current understanding of the origin and evolution of the Plasmodium genus.,The nature of these discoveries and the manner in which they are made are then used to lay out a series of opportunities and challenges for the next wave of parasite hunters.

Since 2000, human malaria cases in Malaysia were rapidly reduced with the use of insecticides in Indoor Residual Spray (IRS) and Long-Lasting Insecticide Net (LLIN).,Unfortunately, monkey malaria in humans has shown an increase especially in Sabah and Sarawak.,The insecticide currently used in IRS is deltamethrin K-Othrine® WG 250 wettable granule, targeting mosquitoes that rest and feed indoor.,In Sabah, the primary vector for knowlesi malaria is An. balabacensis a species known to bite outdoor.,This study evaluates an alternative method, the Outdoor Residual Spray (ORS) using a novel formulation of deltamethrin K-Othrine® (PolyZone) to examine it suitability to control knowlesi malaria vector in Sabah, compared to the current method.,The study was performed at seven villages in Sabah having similar type of houses (wood, bamboo and concrete).,Houses were sprayed with deltamethrin K-Othrine® (PolyZone) at two different dosages, 25 mg/m2 and 30 mg/m2 and deltamethrin K-Othrine® WG 250 wettable granule at 25 mg/m2, sprayed indoor and outdoor.,Residual activity on different walls was assessed using standard cone bioassay techniques.,For larval surveillances, potential breeding sites were surveyed.,Larvae were collected and identified, pre and post spraying.,Adult survey was done using Human Landing Catch (HLC) performed outdoor and indoor.,Detection of malaria parasite in adults was conducted via microscopy and molecular methods.,Deltamethrin K-Othrine® (PolyZone) showed higher efficacy when sprayed outdoor.,The efficacy was found varied when sprayed on different types of wall surfaces.,Deltamethrin K-Othrine® (PolyZone) at 25 mg/m2 was the most effective with regards to ability to high mortality and effective knock down (KD).,The vector population was reduced significantly post-spraying and reduction in breeding sites as well.,The number of simian malaria infected vector, human and simian malaria transmission were also greatly reduced.

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.

Casein kinase 1 (CK1) is a pleiotropic protein kinase implicated in several fundamental processes of eukaryotic cell biology.,Plasmodium falciparum encodes a single CK1 isoform, PfCK1, that is expressed at all stages of the parasite’s life cycle.,We have previously shown that the pfck1 gene cannot be disrupted, but that the locus can be modified if no loss-of-function is incurred, suggesting an important role for this kinase in intra-erythrocytic asexual proliferation.,Here, we report on the use of parasite lines expressing GFP- or His-tagged PfCK1 from the endogenous locus to investigate (i) the dynamics of PfCK1 localisation during the asexual cycle in red blood cells, and (ii) potential interactors of PfCK1, so as to gain insight into the involvement of the enzyme in specific cellular processes.,Immunofluorescence analysis reveals a dynamic localisation of PfCK1, with evidence for a pool of the enzyme being directed to the membrane of the host erythrocyte in the early stages of infection, followed by a predominantly intra-parasite localisation in trophozoites and schizonts and association with micronemes in merozoites.,Furthermore, we present strong evidence that a pool of enzymatically active PfCK1 is secreted into the culture supernatant, demonstrating that PfCK1 is an ectokinase.,Our interactome experiments and ensuing kinase assays using recombinant PfCK1 to phosphorylate putative interactors in vitro suggest an involvement of PfCK1 in many cellular processes such as mRNA splicing, protein trafficking, ribosomal, and host cell invasion.

Exosomes are 30-100-nm membrane vesicles of endocytic origin that are released after the fusion of multivesicular bodies (MVBs) with the plasma membrane.,While initial studies suggested that the role of exosomes was limited to the removal of proteins during the maturation of reticulocytes to erythrocytes, recent studies indicate that they are produced by different types of cells and are involved in promoting inter-cellular communication and antigen presentation.,Here, we describe the isolation and characterization of exosomes from peripheral blood of BALB/c mice infected with the reticulocyte-prone non-lethal Plasmodium yoelii 17X strain.,Importantly, proteomic analysis revealed the presence of parasite proteins in these vesicles.,Moreover, immunization of mice with purified exosomes elicited IgG antibodies capable of recognizing P. yoelii-infected red blood cells.,Furthermore, lethal challenge of immunized mice with the normocyte-prone lethal P. yoelii 17XL strain caused a significant attenuation in the course of parasitaemia, increased survival time, and altered the cell tropism to reticulocytes.,These results were obtained also when the exosomes were isolated from a P. yoelii-infected reticulocyte culture indicating that reticulocyte-derived exosomes carry antigens and are involved in immune modulation.,Moreover, inclusion of CpG ODN 1826 in exosome immunizations elicited IgG2a and IgG2b antibodies and promoted survival, clearance of parasites and subsequent sterile protection of 83% of the animals challenged with P. yoelli 17XL.,To our knowledge, this is the first report of immune responses elicited by exosomes derived from reticulocytes opening new avenues for the modulation of anti-malaria responses.

Numerous studies have been carried out on assessing the prevalence of intestinal parasites infections (IPIs) amongpreschool and school-age children in Ethiopia, but there is lack of study systematically gathered and analyzedinformation for policymakers.,Therefore, the aim of this systematic review and meta-analysis was to provide a summary on prevalence, geographical distribution and trends of IPIs among preschool and school-age childrenin Ethiopia.,The search were carried out in Medline via PubMed, Scopus, Science Direct, Web of Science, and Google Scholar from 1996to July2019 for studies describing prevalence of IPIs among preschooland school-age children.,We conducted meta-regression to understand the trends and the source of heterogeneity and pooled the prevalence using ‘metaprop’ command using STATA software version 14.,Eighty-three(83) studies examining 56,786 fecal specimens were included.,The prevalence of IPIs was 48%(95%CI: 42 to 53%) and showedsignificantly decreasing trends 17% (95% CI: 2.5 to 32%) for each consecutive 6 years) and was similar in males and females.,The pooled prevalence in years 1997-2002, 2003-2008, 2009-2014 and > 2014 was 71% (95% CI: 57 to 86%), 42% (95% CI: 27 to 56%), 48% (95% CI: 40 to 56%) and 42% (95% CI: 34 to 49%), respectively.,Poly-parasitism was observed in 16% (95% CI: 13 to 19%,) of the cases.,Intestinal parasite infections are highly prevalent among preschool and school-age children and well distributed across the regional states of Ethiopia.,Southern and Amhara regional states carry the highest burden.,We observed significant decreasing trends in prevalence of IPIs among preschool and school-ageEthiopian children over the last two decades.,Therefore, this study is important to locate the geographical distribution and identified high risk areas that should be prioritized further interventions, which complement global efforts towards elimination of IPIs infections by 2020.

As a result of urbanization, eating and drinking from food service establishments is becoming a common practice in developing countries like Ethiopia, which increases the chances of food borne diseases.,The health status and hygiene practices of food handlers are the major determinants of food contamination.,In developing countries where there are poor regulatory systems for food hygiene, food handlers are often appointed without screening for possible infections associated with poor hygiene like intestinal parasites.,This study aimed at determining the prevalence and predictors of intestinal parasites and assessing the hygiene practices among food handlers in Yebu Town, southwest Ethiopia.,A cross-sectional study was conducted among a total of 118 food handlers in Yebu Town in January 2011.,Fresh stool specimens were collected and processed using both direct wet mount and Formol ether concentration techniques.,The overall prevalence of intestinal parasites among the study subjects was 44.1% (52/118).,Ascaris lumbricoides and hookworm spp were the predominant parasites identified from the stool of study participants.,Age above 35 years (AOR: 4.8, 95% CI: 1.1, 21.8), no regular practice of washing hands before a meal (AOR: 7.8, 95% CI: 2.8, 24.8), and untrimmed finger nail (AOR: 14.7, 95% CI: 2.8, 75.4) were independent predictors of intestinal parasitic infection among the food handlers.,The present study showed high prevalence of intestinal parasites among the study subjects.,The study also revealed poor personal hygiene like poor practice of hand washing and poor finger nail hygiene.,Therefore, much has to be done to improve the personal hygiene of the food handlers.,Pre-placement and periodic screening of food handlers for parasites and prompt treatment, and health education on regular trimming or cleaning of fingernails would be the way forward for prevention of food borne diseases.

The cornerstone of current schistosomiasis control programmes is delivery of praziquantel to at-risk populations.,Such preventive chemotherapy requires accurate information on the geographic distribution of infection, yet the performance of alternative survey designs for estimating prevalence and converting this into treatment decisions has not been thoroughly evaluated.,We used baseline schistosomiasis mapping surveys from three countries (Malawi, Côte d’Ivoire and Liberia) to generate spatially realistic gold standard datasets, against which we tested alternative two-stage cluster survey designs.,We assessed how sampling different numbers of schools per district (2-20) and children per school (10-50) influences the accuracy of prevalence estimates and treatment class assignment, and we compared survey cost-efficiency using data from Malawi.,Due to the focal nature of schistosomiasis, up to 53% simulated surveys involving 2-5 schools per district failed to detect schistosomiasis in low endemicity areas (1-10% prevalence).,Increasing the number of schools surveyed per district improved treatment class assignment far more than increasing the number of children sampled per school.,For Malawi, surveys of 15 schools per district and 20-30 children per school reliably detected endemic schistosomiasis and maximised cost-efficiency.,In sensitivity analyses where treatment costs and the country considered were varied, optimal survey size was remarkably consistent, with cost-efficiency maximised at 15-20 schools per district.,Among two-stage cluster surveys for schistosomiasis, our simulations indicated that surveying 15-20 schools per district and 20-30 children per school optimised cost-efficiency and minimised the risk of under-treatment, with surveys involving more schools of greater cost-efficiency as treatment costs rose.

In 2004 Niger established a large scale schistosomiasis and soil-transmitted helminths control programme targeting children aged 5-14 years and adults.,In two years 4.3 million treatments were delivered in 40 districts using school based and community distribution.,Four districts were surveyed in 2006 to estimate the economic cost per district, per treatment and per schistosomiasis infection averted.,The study compares the costs of treatment at start up and in a subsequent year, identifies the allocation of costs by activity, input and organisation, and assesses the cost of treatment.,The cost of delivery provided by teachers is compared to cost of delivery by community distributers (CDD).,The total economic cost of the programme including programmatic, national and local government costs and international support in four study districts, over two years, was US$ 456,718; an economic cost/treatment of $0.58.,The full economic delivery cost of school based treatment in 2005/06 was $0.76, and for community distribution was $0.46.,Including only the programme costs the figures are $0.47 and $0.41 respectively.,Differences at sub-district are more marked.,This is partly explained by the fact that a CDD treats 5.8 people for every one treated in school.,The range in cost effectiveness for both direct and direct and indirect treatments is quantified and the need to develop and refine such estimates is emphasised.,The relative cost effectiveness of school and community delivery differs by country according to the composition of the population treated, the numbers targeted and treated at school and in the community, the cost and frequency of training teachers and CDDs.,Options analysis of technical and implementation alternatives including a financial analysis should form part of the programme design process.

Helminths are endemic in more than half of the world’s countries, raising serious public health concerns.,Accurate diagnosis of helminth infection is crucial to control strategies.,Traditional parasitological methods, serological tests and PCR-based assays are the major means of the diagnosis of helminth infection, but they are time-consuming and/or expensive, and sometimes provide inaccurate results.,Loop mediated isothermal amplification (LAMP) assay, a sensitive, simple and rapid method was therefore developed for detection of helminths.,This study aims to discuss the current status of application of LAMP on helminths detection and to make a comprehensive evaluation about this updated technology and its future outlook by comparing with several other diagnostic methods.,This review summarizes LAMP assay applied for helminth detection and helminthiasis surveillance.,The basic principle of LAMP is introduced to help better understand its characteristics and each reported assay is assessed mainly based on its detection sensitivity, specificity and limitations, in comparison with other common diagnostic tests.,Moreover, we discuss the limitations of the assays so as to clarify some potential ways of improvement.,Here, we summarize and discuss the advantages, disadvantages and promising future of LAMP in heliminth detection, which is expected to help update current knowledge and future perspectives of LAMP in highly sensitive and specific diagnosis and surveillance of helminthiasis and other parasitic diseases, and can contribute to the elimination of the diseases from endemic areas.,The online version of this article (10.1186/s40249-019-0530-z) contains supplementary material, which is available to authorized users.

Amphimeriasis is a fish-borne disease caused by the liver fluke Amphimerus spp. that has recently been reported as endemic in the tropical Pacific side of Ecuador with a high prevalence in humans and domestic animals.,The diagnosis is based on the stool examination to identify parasite eggs, but it lacks sensitivity.,Additionally, the morphology of the eggs may be confounded with other liver and intestinal flukes.,No immunological or molecular methods have been developed to date.,New diagnostic techniques for specific and sensitive detection of Amphimerus spp.,DNA in clinical samples are needed.,A LAMP targeting a sequence of the Amphimerus sp. internal transcribed spacer 2 region was designed.,Amphimerus sp.,DNA was obtained from adult worms recovered from animals and used to optimize the molecular assays.,Conventional PCR was performed using outer primers F3-B3 to verify the proper amplification of the Amphimerus sp.,DNA target sequence.,LAMP was optimized using different reaction mixtures and temperatures, and it was finally set up as LAMPhimerus.,The specificity and sensitivity of both PCR and LAMP were evaluated.,The detection limit was 1 pg of genomic DNA.,Field testing was done using 44 human stool samples collected from localities where fluke is endemic.,Twenty-five samples were microscopy positive for Amphimerus sp. eggs detection.,In molecular testing, PCR F3-B3 was ineffective when DNA from fecal samples was used.,When testing all human stool samples included in our study, the diagnostic parameters for the sensitivity and specificity were calculated for our LAMPhimerus assay, which were 76.67% and 80.77%, respectively.,We have developed and evaluated, for the first time, a specific and sensitive LAMP assay for detecting Amphimerus sp. in human stool samples.,The procedure has been named LAMPhimerus method and has the potential to be adapted for field diagnosis and disease surveillance in amphimeriasis-endemic areas.,Future large-scale studies will assess the applicability of this novel LAMP assay.

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.

Plasmodium vivax relapse infections occur following activation of latent liver-stages parasites (hypnozoites) causing new blood-stage infections weeks to months after the initial infection.,We develop a within-host mathematical model of liver-stage hypnozoites, and validate it against data from tropical strains of P. vivax.,The within-host model is embedded in a P. vivax transmission model to demonstrate the build-up of the hypnozoite reservoir following new infections and its depletion through hypnozoite activation and death.,The hypnozoite reservoir is predicted to be over-dispersed with many individuals having few or no hypnozoites, and some having intensely infected livers.,Individuals with more hypnozoites are predicted to experience more relapses and contribute more to onwards P. vivax transmission.,Incorporating hypnozoite killing drugs such as primaquine into first-line treatment regimens is predicted to cause substantial reductions in P. vivax transmission as individuals with the most hypnozoites are more likely to relapse and be targeted for treatment.,DOI:http://dx.doi.org/10.7554/eLife.04692.001,Malaria is one of the world's most deadly infections, causing 100s of 1000s of deaths each year despite being both preventable and curable.,Malaria is caused by Plasmodium parasites, which are transmitted between humans by mosquitoes.,When a mosquito bites a human, Plasmodium is injected into the bloodstream with the mosquito's saliva.,The parasite then travels through the bloodstream to the liver, infects liver cells and multiplies within those cells without causing any noticeable symptoms.,After remaining silent in the liver for weeks or months, the now abundant parasite ruptures the host liver cell, re-enters the bloodstream, and begins infecting red blood cells.,If another mosquito bites the infected individual and takes a blood meal, the parasite moves into the mosquito and the cycle of transmission continues.,There are several species of Plasmodium that are known to cause malaria.,The most widely studied species is P. falciparum, which also causes one of the deadliest types of malaria.,However, another Plasmodium species called P. vivax is the most widely distributed species and, despite being less virulent than P. falciparum, is particularly dangerous because it causes recurring malaria.,In contrast to P. falciparum, P. vivax has the ability to form hypnozoites: a dormant form of the parasite that can remain inside liver cells for long periods of time, sometimes for years.,The reservoir of P. vivax hypnozoites can regularly populate the bloodstream with the infectious form of the parasite, triggering relapses of malaria.,Even if an individual suffering a relapse receives prompt treatment to clear parasites in the blood, more parasites may emerge from the liver and cause new blood-stage infections.,White et al. developed a mathematical model to help understand how P. vivax is transmitted.,Unlike many of the established models of malaria transmission, the new model accounts for the reservoir of P. vivax hypnozoites in the liver, and assumes that hypnozoites in the reservoir either die, or are activated and enter the bloodstream, at a constant rate.,This produces patterns that closely match how often relapses occur in patients.,White et al. go on to predict that although many infected people have few or no hypnozoites in their liver, some have many hypnozoites, and these people are more likely to suffer from malaria relapses.,This suggests that if the initial treatments given to malaria sufferers incorporate additional drugs that kill the hypnozoites in the liver, then it may be possible to substantially reduce the extent of P. vivax transmission.,DOI:http://dx.doi.org/10.7554/eLife.04692.002

Malaria is a major public health risk in Rwanda where children and pregnant women are most vulnerable.,This infectious disease remains the main cause of morbidity and mortality among children in Rwanda.,The main objectives of this study were to assess the prevalence of malaria among children aged six months to 14 years old in Rwanda and to identify the factors associated with malaria in this age group.,This study used data from the 2017 Rwanda Malaria Indicator Survey.,Due to the complex design used in sampling, a survey logistic regression model was used to fit the data and the outcome variable was the presence or absence of malaria.,This study considered 8209 children in the analysis and the prevalence of malaria was 14.0%.,This rate was higher among children aged 5-9 years old (15.6%), compared to other age groups.,Evidently, the prevalence of malaria was also higher among children from poor families (19.4%) compared to children from the richest families (4.3%).,The prevalence of malaria was higher among children from rural households (16.2%) compared to children from urban households (3.4%).,The results revealed that other significant factors associated with malaria were: the gender of the child, the number of household members, whether the household had mosquito bed nets for sleeping, whether the dwelling had undergone indoor residual spraying in the 12 months prior to the survey, the location of the household’s source of drinking water, the main wall materials of the dwelling, and the age of the head of the household.,The prevalence of malaria was also high among children living in houses with walls built from poorly suited materials; this suggests the need for intervention in construction materials.,Further, it was found that the Eastern Province also needs special consideration in malaria control due to the higher prevalence of the disease among its residents, compared to those in other provinces.

Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ), given each month during the transmission season, is recommended for children living in areas of the Sahel where malaria transmission is highly seasonal.,The recommendation for SMC is currently limited to children under five years of age, but, in many areas of seasonal transmission, the burden in older children may justify extending this age limit.,This study was done to determine the effectiveness of SMC in Senegalese children up to ten years of age.,SMC was introduced into three districts over three years in central Senegal using a stepped-wedge cluster-randomised design.,A census of the population was undertaken and a surveillance system was established to record all deaths and to record all cases of malaria seen at health facilities.,A pharmacovigilance system was put in place to detect adverse drug reactions.,Fifty-four health posts were randomised.,Nine started implementation of SMC in 2008, 18 in 2009, and a further 18 in 2010, with 9 remaining as controls.,In the first year of implementation, SMC was delivered to children aged 3-59 months; the age range was then extended for the latter two years of the study to include children up to 10 years of age.,Cluster sample surveys at the end of each transmission season were done to measure coverage of SMC and the prevalence of parasitaemia and anaemia, to monitor molecular markers of drug resistance, and to measure insecticide-treated net (ITN) use.,Entomological monitoring and assessment of costs of delivery in each health post and of community attitudes to SMC were also undertaken.,About 780,000 treatments were administered over three years.,Coverage exceeded 80% each month.,Mortality, the primary endpoint, was similar in SMC and control areas (4.6 and 4.5 per 1000 respectively in children under 5 years and 1.3 and 1.2 per 1000 in children 5-9 years of age; the overall mortality rate ratio [SMC: no SMC] was 0.90, 95% CI 0.68-1.2, p = 0.496).,A reduction of 60% (95% CI 54%-64%, p < 0.001) in the incidence of malaria cases confirmed by a rapid diagnostic test (RDT) and a reduction of 69% (95% CI 65%-72%, p < 0.001) in the number of treatments for malaria (confirmed and unconfirmed) was observed in children.,In areas where SMC was implemented, incidence of confirmed malaria in adults and in children too old to receive SMC was reduced by 26% (95% CI 18%-33%, p < 0.001) and the total number of treatments for malaria (confirmed and unconfirmed) in these older age groups was reduced by 29% (95% CI 21%-35%, p < 0.001).,One hundred and twenty-three children were admitted to hospital with a diagnosis of severe malaria, with 64 in control areas and 59 in SMC areas, showing a reduction in the incidence rate of severe disease of 45% (95% CI 5%-68%, p = 0.031).,Estimates of the reduction in the prevalence of parasitaemia at the end of the transmission season in SMC areas were 68% (95% CI 35%-85%) p = 0.002 in 2008, 84% (95% CI 58%-94%, p < 0.001) in 2009, and 30% (95% CI -130%-79%, p = 0.56) in 2010.,SMC was well tolerated with no serious adverse reactions attributable to SMC drugs.,Vomiting was the most commonly reported mild adverse event but was reported in less than 1% of treatments.,The average cost of delivery was US$0.50 per child per month, but varied widely depending on the size of the health post.,Limitations included the low rate of mortality, which limited our ability to detect an effect on this endpoint.,SMC substantially reduced the incidence of outpatient cases of malaria and of severe malaria in children, but no difference in all-cause mortality was observed.,Introduction of SMC was associated with an overall reduction in malaria incidence in untreated age groups.,In many areas of Africa with seasonal malaria, there is a substantial burden in older children that could be prevented by SMC.,SMC in older children is well tolerated and effective and can contribute to reducing malaria transmission.,ClinicalTrials.gov NCT00712374,In a stepped-wedge cluster-randomized trial, Paul J.,Milligan and colleagues determine the effectiveness of SMC in Senegalese children up to ten years of age.

Schistosomiasis remains one of the most prevalent parasitic infections in the world and has significant economic and public health consequences, particularly in poor communities.,Reliable and accurate diagnosis plays a key role in surveillance, prevention and control of schistosomiasis.,Currently, the microscopic Kato Katz (KK) stool thick smear technique is the most commonly used method to diagnose Schistosoma mansoni infections in epidemiological surveys.,It is well-known that the sensitivity of this parasitological method decreases when infection intensities are moderate to low, however.,The urine-based Point-of Care Circulating Cathodic Antigen (POC-CCA) test has been extensively evaluated as a further diagnostic tool.,Several studies have shown that the POC-CCA test is more sensitive but less specific than the KK method.,However, to clarify the meaning of inconsistent results between KK and POC-CCA tests in clinical routine, this study compares the accuracy of microscopy and POC-CCA versus real-time polymerase chain reaction (real-time PCR) results of urine and faecal samples from African school children participants.,This was a school-based cross-sectional study conducted in 2015 among 305 school children aged 7-16 years from two primary schools located in Ilemela and Magu Districts, north-western Tanzania.,Single stool and urine samples were collected from each participant and examined for the presence of Schistosoma mansoni eggs, parasite antigen, and parasite DNA using KK thick smears, POC-CCA tests, and real-time PCR, respectively.,The prevalence of S. mansoni infection, calculated by KK was 85.2%, by real-time PCR 92.9% and by POC-CCA 94.9%.,In comparison to KK, the POC-CCA and real-time PCR tests had sensitivities of 89.7% and 99.5% and specificities of 22.73% and 29.55%, respectively.,However, due to the known limitations of the KK assay, we also used latent class analysis (LCA) that included POC-CCA, KK, and schistosome-specific real-time PCR results to determine their sensitivities and specificities.,The POC-CCA test had the highest sensitivity (99.5%) and a specificity of 63.4% by LCA and the real-time PCR test had a sensitivity of 98.7% and the highest specificity (81.2%).,In moderate and high prevalence areas, the POC-CCA cassette test is more sensitive than the KK method and can be used for screening and geographical mapping of S. mansoni infections.,Real-time PCR is highly sensitive and also shows the highest specificity among the 3 investigated diagnostic procedures.,It can offer added value in diagnosing schistosomiasis.

Recent evidence indicates that pre-school children (PSC) living in S. mansoni highly endemic areas are at similar risk of schistosomiasis infection and morbidity as their school aged siblings.,Recognizing this fact, the World Health Organization (WHO) is considering including this age group in highly endemic areas in control programmes using mass drug administration (MDA).,However, detailed epidemiological information on S. mansoni infection among PSC is lacking for many endemic areas, specifically in Tanzania.,This study was conducted to determine the prevalence of S. mansoni infection and its associated risk factors among PSC in Ukerewe Island, North-Western Tanzania.,This was a cross-sectional study, which studied 400 PSC aged 1-6 years.,The Kato-Katz (K-K) technique and the point of care circulating cathodic antigen (CCA) immunodiagnostic test were used to diagnose S. mansoni infection in stool and urine samples respectively.,A pre-tested questionnaire was used to collect demographic data and water contact behaviour of the children from their parents/guardians.,Based on the K-K technique, 44.4 % (95 % CI: 39.4-49.4) pre-school children were infected with S. mansoni and the overall geometric mean eggs per gram of faeces (GM-epg) was 110.6 epg with 38.2 and 14.7 % having moderate and heavy intensity infections respectively.,Based on the CCA, 80.1 %, (95 % CI: 76.0-84.0) were infected if a trace was considered positive, and 45.9 %, (95 % CI: 40.9-50.9), were infected if a trace was considered negative.,Reported history of lake visits (AOR = 2.31, 95 % CI: 1.06-5.01, P < 0.03) and the proximity to the lake shore (<500 m) (AOR = 2.09, 95 % CI: 1.05-4.14, P < 0.03) were significantly associated with S. mansoni infection.,Reported lake visit frequency (4-7 days/week) was associated with heavy intensities of S. mansoni infection (P < 0.00).,The prevalence of S. mansoni infection in the study population using K-K and CCA-trace-negative was moderate.,The frequency of lake visits and the proximity to the lake shore were associated with the infection of S. mansoni and its intensity.,These findings call for the need to include the PSC in MDA programmes, public health education and provision of safe water for bathing.

Sarcoptic mange is a globally distributed disease caused by the burrowing mite Sarcoptes scabiei, which also causes scabies in humans.,A wide and increasing number of wild mammal species are reported to be susceptible to mange; however, the impacts of the disease in wildlife populations, mechanisms involved in its eco-epidemiological dynamics, and risks to public and ecosystem health are still unclear.,Major gaps exist concerning S. scabiei host specificity and the mechanisms involved in the different presentations of the disease, which change between individuals and species.,Immunological responses to the mite may have a relevant role explaining these different susceptibilities, as these affect the clinical signs, and consequently, the severity of the disease.,Recently, some studies have suggested sarcoptic mange as an emerging threat for wildlife, based on several outbreaks with increased severity, geographical expansions, and novel wild hosts affected.,Disease ecology experts convened for the “International Meeting on Sarcoptic Mange in Wildlife” on 4-5 June 2018, hosted by the Department of Fish and Wildlife Conservation at Virginia Tech in Blacksburg, Virginia, USA.,The meeting had a structure of (i) pre-workshop review; (ii) presentation and discussions; and (iii) identification of priority research questions to understand sarcoptic mange in wildlife.,The workgroup concluded that research priorities should be on determining the variation in modes of transmission for S. scabiei in wildlife, factors associated with the variation of disease severity among species, and long-terms effects of the mange in wildlife populations.,In this note we summarize the main discussions and research gaps identified by the experts.

Due to its suspected increase in host range and subsequent global diversification, Sarcoptes scabiei has important implications at a global scale for wildlife conservation and animal and human health.,The introduction of this pathogen into new locations and hosts has been shown to produce high morbidity and mortality, a situation observed recently in Australian and North American wildlife.,Of the seven native animal species in Australia known to be infested by S. scabiei, the bare-nosed wombat (Vombatus ursinus) suffers the greatest with significant population declines having been observed in New South Wales and Tasmania.,The origins of sarcoptic mange in Australian native animals are poorly understood, with the most consistent conclusion being that mange was introduced by settlers and their dogs and subsequently becoming a major burden to native wildlife.,Four studies exist addressing the origins of mange in Australia, but all Australian S. scabiei samples derive from only two of these studies.,This review highlights this paucity of phylogenetic knowledge of S. scabiei within Australia, and suggests further research is needed to confidently determine the origin, or multiple origins, of this parasite.,At the global scale, numerous genetic studies have attempted to reveal how the host species and host geographic location influence S. scabiei phylogenetics.,This review includes an analysis of the global literature, revealing that inconsistent use of gene loci across studies significantly influences phylogenetic inference.,Furthermore, by performing a contemporary analytical approach on existing data, it is apparent that (i) new S. scabiei samples, (ii) appropriate gene loci targets, and (iii) advanced phylogenetic approaches are necessary to more confidently comprehend the origins of mange in Australia.,Advancing this field of research will aid in understanding the mechanisms of spillover for mange and other parasites globally.,The online version of this article (doi:10.1186/s13071-016-1578-2) contains supplementary material, which is available to authorized users.

Twenty diseases are recognized as neglected tropical diseases (NTDs) by World Health Assembly resolutions, including human filarial diseases.,The end of NTDs is embedded within the Sustainable Development Goals for 2030, under target 3.3.,Onchocerciasis afflicts approximately 20.9 million people worldwide with > 90% of those infected residing in Africa.,Control programs have made tremendous efforts in the management of onchocerciasis by mass drug administration and aerial larviciding; however, disease elimination is not yet achieved.,In the new WHO roadmap, it is recognized that new drugs or drug regimens that kill or permanently sterilize adult filarial worms would significantly improve elimination timelines and accelerate the achievement of the program goal of disease elimination.,Drug development is, however, handicapped by high attrition rates, and many promising molecules fail in preclinical development or in subsequent toxicological, safety and efficacy testing; thus, research and development (R&D) costs are, in aggregate, very high.,Drug discovery and development for NTDs is largely driven by unmet medical needs put forward by the global health community; the area is underfunded and since no high return on investment is possible, there is no dedicated drug development pipeline for human filariasis.,Repurposing existing drugs is one approach to filling the drug development pipeline for human filariasis.,The high cost and slow pace of discovery and development of new drugs has led to the repurposing of “old” drugs, as this is more cost-effective and allows development timelines to be shortened.,However, even if a drug is marketed for a human or veterinary indication, the safety margin and dosing regimen will need to be re-evaluated to determine the risk in humans.,Drug repurposing is a promising approach to enlarging the pool of active molecules in the drug development pipeline.,Another consideration when providing new treatment options is the use of combinations, which is not addressed in this review.,We here summarize recent advances in the late preclinical or early clinical stage in the search for a potent macrofilaricide, including drugs against the nematode and against its endosymbiont, Wolbachia pipientis.

Mass treatment with ivermectin controls onchocerciasis as a public health problem, but it was not known if it could also interrupt transmission and eliminate the parasite in endemic foci in Africa where vectors are highly efficient.,A longitudinal study was undertaken in three hyperendemic foci in Mali and Senegal with 15 to 17 years of annual or six-monthly ivermectin treatment in order to assess residual levels of infection and transmission, and test whether treatment could be safely stopped.,This article reports the results of the final evaluations up to 5 years after the last treatment.,Skin snip surveys were undertaken in 131 villages where 29,753 people were examined and 492,600 blackflies were analyzed for the presence of Onchocerca volvulus larva using a specific DNA probe.,There was a declining trend in infection and transmission levels after the last treatment.,In two sites the prevalence of microfilaria and vector infectivity rate were zero 3 to 4 years after the last treatment.,In the third site, where infection levels were comparatively high before stopping treatment, there was also a consistent decline in infection and transmission to very low levels 3 to 5 years after stopping treatment.,All infection and transmission indicators were below postulated thresholds for elimination.,The study has established the proof of principle that onchocerciasis elimination with ivermectin treatment is feasible in at least some endemic foci in Africa.,The study results have been instrumental for the current evolution from onchocerciasis control to elimination in Africa.

Recent studies have demonstrated the deletion of the histidine-rich protein 2 (PfHRP2) gene (pfhrp2) in field isolates of Plasmodium falciparum, which could result in false negative test results when PfHRP2-based rapid diagnostic tests (RDTs) are used for malaria diagnosis.,Although primary diagnosis of malaria in Honduras is determined based on microscopy, RDTs may be useful in remote areas.,In this study, it was investigated whether there are deletions of the pfhrp2, pfhrp3 and their respective flanking genes in 68 P. falciparum parasite isolates collected from the city of Puerto Lempira, Honduras.,In addition, further investigation considered the possible correlation between parasite population structure and the distribution of these gene deletions by genotyping seven neutral microsatellites.,Sixty-eight samples used in this study, which were obtained from a previous chloroquine efficacy study, were utilized in the analysis.,All samples were genotyped for pfhrp2, pfhrp3 and flanking genes by PCR.,The samples were then genotyped for seven neutral microsatellites in order to determine the parasite population structure in Puerto Lempira at the time of sample collection.,It was found that all samples were positive for pfhrp2 and its flanking genes on chromosome 8.,However, only 50% of the samples were positive for pfhrp3 and its neighboring genes while the rest were either pfhrp3-negative only or had deleted a combination of pfhrp3 and its neighbouring genes on chromosome 13.,Population structure analysis predicted that there are at least two distinct parasite population clusters in this sample population.,It was also determined that a greater proportion of parasites with pfhrp3-(and flanking gene) deletions belonged to one cluster compared to the other.,The findings indicate that the P. falciparum parasite population in the municipality of Puerto Lempira maintains the pfhrp2 gene and that PfHRP2-based RDTs could be considered for use in this region; however continued monitoring of parasite population will be useful to detect any parasites with deletions of pfhrp2.

Malaria rapid diagnostic tests (RDTs) offer significant potential to improve the diagnosis of malaria, and are playing an increasing role in malaria case management, control and elimination.,Peru, along with other South American countries, is moving to introduce malaria RDTs as components of malaria control programmes supported by the Global Fund for AIDS, TB and malaria.,The selection of the most suitable malaria RDTs is critical to the success of the programmes.,Eight of nine microscopy positive P. falciparum samples collected in Iquitos, Peru tested negative or weak positive using HRP2-detecting RDTs.,These samples were tested for the presence of pfhrp2 and pfhrp3 and their flanking genes by PCR, as well as the presence of HRP proteins by ELISA.,To investigate for geographic extent of HRP-deleted parasites and their temporal occurrence a retrospective study was undertaken on 148 microscopy positive P. falciparum samples collected in different areas of the Amazon region of Peru.,Eight of the nine isolates lacked the pfhrp2 and/or pfhrp3 genes and one or both flanking genes, and the absence of HRP was confirmed by ELISA.,The retrospective study showed that 61 (41%) and 103 (70%) of the 148 samples lacked the pfhrp2 or pfhrp3 genes respectively, with 32 (21.6%) samples lacking both hrp genes.,This is the first documentation of P. falciparum field isolates lacking pfhrp2 and/or pfhrp3.,The high frequency and wide distribution of different parasites lacking pfhrp2 and/or pfhrp3 in widely dispersed areas in the Peruvian Amazon implies that malaria RDTs targeting HRP2 will fail to detect a high proportion of P. falciparum in malaria-endemic areas of Peru and should not be used.,RDTs detecting parasite LDH or aldolase and quality microscopy should be use for malaria diagnosis in this region.,There is an urgent need for investigation of the abundance and geographic distribution of these parasites in Peru and neighbouring countries.

The principal objective of this study was to assess a modeling approach to Lu. longipalpis distribution in an urban scenario, discriminating micro-scale landscape variables at microhabitat and macrohabitat scales and the presence from the abundance of the vector.,For this objective, we studied vectors and domestic reservoirs and evaluated different environmental variables simultaneously, so we constructed a set of 13 models to account for micro-habitats, macro-habitats and mixed-habitats.,We captured a total of 853 sandflies, of which 98.35% were Lu. longipalpis.,We sampled a total of 197 dogs; 177 of which were associated with households where insects were sampled.,Positive rK39 dogs represented 16.75% of the total, of which 47% were asymptomatic.,Distance to the border of the city and high to medium density vegetation cover ended to be the explanatory variables, all positive, for the presence of sandflies in the city.,All variables in the abundance model ended to be explanatory, trees around the trap, distance to the stream and its quadratic, being the last one the only one with negative coefficient indicating that the maximum abundance was associated with medium values of distance to the stream.,The spatial distribution of dogs infected with L. infantum showed a heterogeneous pattern throughout the city; however, we could not confirm an association of the distribution with the variables assessed.,In relation to Lu. longipalpis distribution, the strategy to discriminate the micro-spatial scales at which the environmental variables were recorded allowed us to associate presence with macrohabitat variables and abundance with microhabitat and macrohabitat variables.,Based on the variables associated with Lu. longipalpis, the model will be validated in other cities and environmental surveillance, and control interventions will be proposed and evaluated in the microscale level and integrated with socio-cultural approaches and programmatic and village (mesoscale) strategies.

Sand flies (Diptera: Psychodidae) are the vectors of Leishmania parasites, the causative agents of leishmaniasis.,Cutaneous leishmaniasis is an increasing public health problem in the Republic of Suriname and is mainly caused by Leishmania (Vianna) guyanensis, but L.,(V.) braziliensis, L.,(L.) amazonensis, and L.,(V.) naiffi also infect humans.,Transmission occurs predominantly in the forested hinterland of the country.,Information regarding the potential vectors of leishmaniasis in Suriname is limited.,This study aims to broaden the knowledge about vectors involved in the transmission of cutaneous leishmaniasis in Suriname.,For this purpose, sand flies were characterized in various foci of cutaneous leishmaniasis in the country, the districts of Para, Brokopondo, and Sipaliwini.,Sand flies were collected in areas around mining plots and villages using CDC light traps in the period between February 2011 and March 2013.,They were categorized by examination of the spermathecea (females) and the external genitalia (males).,A total of 2,743 sand fly specimens belonging to 34 different species were captured, including four species (Lutzomyia aragaoi, Lu. ayrozai, Lu. damascenoi, and Lu. sordellii) that had never before been described for Suriname.,Five percent of the catch comprised Lu. squamiventris sensu lato, one female of which was positive with L.,(V.) braziliensis and was captured in a gold mining area in Brokopondo.,Other sand fly species found positive for Leishmania parasites were Lu. trichopyga, Lu. ininii, and Lu. umbratilis, comprising 32, 8, and 4%, respectively, of the catch.,These were captured at gold mining areas in Brokopondo and Sipaliwini, but the Leishmania parasites they had ingested could not be identified due to insufficient amounts of DNA.,The sand fly fauna in Suriname is highly diverse and comprises Lutzomyia species capable of transmitting Leishmania parasites.,Four new Lutzomyia species have been found, and four species - Lu. squamiventris (s.l.), Lu. trichopyga, Lu. ininii, and Lu. umbratilis - have been found to harbor Leishmania parasites.,The latter were among the most abundant species captured.,These observations may contribute to the understanding of leishmaniasis transmission and the development of control programs in Suriname.

Mass drug administration (MDA) was a component of many malaria programs during the eradication era, but later was seldomly deployed due to concerns regarding efficacy and feasibility and fear of accelerating drug resistance.,Recently, however, there has been renewed interest in the role of MDA as an elimination tool.,Following a 2013 Cochrane Review that focused on the quantitative effects of malaria MDA, we have conducted a systematic, qualitative review of published, unpublished, and gray literature documenting past MDA experiences.,We have also consulted with field experts, using their historical experience to provide an informed, contextual perspective on the role of MDA in malaria elimination.,Substantial knowledge gaps remain and more research is necessary, particularly on optimal target population size, methods to improve coverage, and primaquine safety.,Despite these gaps, MDA has been used successfully to control and eliminate Plasmodium falciparum and P. vivax malaria in the past, and should be considered as part of a comprehensive malaria elimination strategy in specific settings.

Pedro Alonso and colleagues introduce the Malaria Eradication Research Agenda (malERA) initiative and the set of articles published in this PLoS Medicine Supplement that distill the research questions key to malaria eradication.,The interruption of malaria transmission worldwide is one of the greatest challenges for international health and development communities.,The current expert view suggests that, by aggressively scaling up control with currently available tools and strategies, much greater gains could be achieved against malaria, including elimination from a number of countries and regions; however, even with maximal effort we will fall short of global eradication.,The Malaria Eradication Research Agenda (malERA) complements the current research agenda-primarily directed towards reducing morbidity and mortality-with one that aims to identify key knowledge gaps and define the strategies and tools that will result in reducing the basic reproduction rate to less than 1, with the ultimate aim of eradication of the parasite from the human population.,Sustained commitment from local communities, civil society, policy leaders, and the scientific community, together with a massive effort to build a strong base of researchers from the endemic areas will be critical factors in the success of this new agenda.

Currently the local P. vivax was sharply decreased while the imported vivax malaria increased in China.,Despite Southeast Asia was still the main import source of vivax malaria, the trend of Africa become serious, especially for west and central Africa.,Herein we have clarified the trend of P. vivax in China from 2004-2012, and made some analysis for the differences of imported vivax back from different regions.,There are significantly different of P. vivax between Southeast Asia and Africa, also the difference was observed for different regions in Africa.,Additionally, we have explored the possibility for the difference of the P. vivax between migrant workers back from west and central Africa and the prevalence of local population.,This reminds us that surveillance and training should be strengthened by medical staffs on the imported P. vivax cases reported especially from west and central Africa, in order to reduce the risk of malaria reintroduction and, specific tools should be developed, as well as the epidemiological study to avoid the misdiagnosis such as P. ovale and P. vivax.

Fascioliasis is a common parasitic disease in livestock in China.,However, human fascioliasis is rarely reported in the country.,Here we describe an outbreak of human fascioliasis in Yunnan province.,We reviewed the complete clinical records of 29 patients and performed an epidemiological investigation on the general human population and animals in the outbreak locality.,Our findings support an outbreak due to Fasciola gigantica with a peak in late November, 2011.,The most common symptoms were remittent fever, epigastric tenderness, and hepatalgia.,Eosinophilia and tunnel-like lesions in ultrasound imaging in the liver were also commonly seen.,Significant improvement of patients’ condition was achieved by administration of triclabendazole®.,Fasciola spp. were discovered in local cattle (28.6%) and goats (26.0%).,Molecular evidence showed a coexistence of F. gigantica and F. hepatica.,However, all eggs seen in humans were confirmed to be F. gigantica.,Herb (Houttuynia cordata) was most likely the source of infections.,Our findings indicate that human fascioliasis is a neglected disease in China.,The distribution of triclabendazole®, the only efficacious drug against human fascioliasis, should be promoted.

Intestinal parasites remain considerable public health problems in low-income countries where poor food hygiene practice is common.,Food handlers, people involved in preparing and serving food, working with poor personal hygiene could pose a potential threat of spreading intestinal parasites to the public in a community.,The aim of this systematic review and meta-analysis was, therefore, to synthesize the pooled prevalence estimate of intestinal parasites and associated pooled odds ratio of hygienic predictors among food handlers of food service establishments in Ethiopia that could aid to further bringing down the burden of intestinal parasites and it can also be used as a springboard for future studies.,We searched exhaustively for studies Published before 20 April 2019 using eight Databases; PubMed, Science Direct, Web of Science, Scopus, Embase, Google Scholar, ProQuest, and Ovid MEDLINE® complemented by the gray literature search.,In the final synthesis, we included twenty study reports.,We used the Cochrane Q test and I2 test to assess heterogeneity of studies, while we employed a funnel plot followed by Egger’s regression asymmetry test and Begg rank correlation methods to evaluate publication bias.,We also performed a point estimates and 95% confidence interval for each study using STATA version 14 statistical software.,The overall pooled prevalence estimate of intestinal parasites among food handlers of food service establishments in Ethiopia was 33.6% (95%CI: 27.6-39.6%).,Among ten intestinal parasites identified from food handlers, Entamoeba histolytica/ dispar (11, 95%CI: 7.9-14.1%) and Ascaris lumbricoides (8.8, 95%CI: 6.4-11.2%) were the most predominant intestinal parasites.,Food handlers who washed hands after toilet use had 54% (OR, 0.46, 95% CI: 0.23-0.94) protection from intestinal parasites compared to those who did not.,This study revealed that intestinal parasitic infections are notable among food handlers of food service establishments in Ethiopia, which may be a risk for transmitting intestinal parasites to food and drinks consumers through the food chain.,Thus, periodic stool checkup, training on intestinal parasitic infections and personal hygiene should be applied to reduce public health and socio-economic impacts of parasitic infections.

In a systematic review and meta-analysis, Eric Strunz and colleagues examine whether improvements in water, sanitation, and hygiene (WASH) practices are associated with reduced risk of infections with soil-transmitted helminths.,Please see later in the article for the Editors' Summary,Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis.,Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH).,The purpose of this study was to quantitatively summarize the relationship between WASH access or practices and soil-transmitted helminth (STH) infection.,We conducted a systematic review and meta-analysis to examine the associations of improved WASH on infection with STH (Ascaris lumbricoides, Trichuris trichiura, hookworm [Ancylostoma duodenale and Necator americanus], and Strongyloides stercoralis).,PubMed, Embase, Web of Science, and LILACS were searched from inception to October 28, 2013 with no language restrictions.,Studies were eligible for inclusion if they provided an estimate for the effect of WASH access or practices on STH infection.,We assessed the quality of published studies with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.,A total of 94 studies met our eligibility criteria; five were randomized controlled trials, whilst most others were cross-sectional studies.,We used random-effects meta-analyses and analyzed only adjusted estimates to help account for heterogeneity and potential confounding respectively.,Use of treated water was associated with lower odds of STH infection (odds ratio [OR] 0.46, 95% CI 0.36-0.60).,Piped water access was associated with lower odds of A. lumbricoides (OR 0.40, 95% CI 0.39-0.41) and T. trichiura infection (OR 0.57, 95% CI 0.45-0.72), but not any STH infection (OR 0.93, 95% CI 0.28-3.11).,Access to sanitation was associated with decreased likelihood of infection with any STH (OR 0.66, 95% CI 0.57-0.76), T. trichiura (OR 0.61, 95% CI 0.50-0.74), and A. lumbricoides (OR 0.62, 95% CI 0.44-0.88), but not with hookworm infection (OR 0.80, 95% CI 0.61-1.06).,Wearing shoes was associated with reduced odds of hookworm infection (OR 0.29, 95% CI 0.18-0.47) and infection with any STH (OR 0.30, 95% CI 0.11-0.83).,Handwashing, both before eating (OR 0.38, 95% CI 0.26-0.55) and after defecating (OR 0.45, 95% CI 0.35-0.58), was associated with lower odds of A. lumbricoides infection.,Soap use or availability was significantly associated with lower infection with any STH (OR 0.53, 95% CI 0.29-0.98), as was handwashing after defecation (OR 0.47, 95% CI 0.24-0.90).,Observational evidence constituted the majority of included literature, which limits any attempt to make causal inferences.,Due to underlying heterogeneity across observational studies, the meta-analysis results reflect an average of many potentially distinct effects, not an average of one specific exposure-outcome relationship.,WASH access and practices are generally associated with reduced odds of STH infection.,Pooled estimates from all meta-analyses, except for two, indicated at least a 33% reduction in odds of infection associated with individual WASH practices or access.,Although most WASH interventions for STH have focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection.,Overall quality of evidence was low due to the preponderance of observational studies, though recent randomized controlled trials have further underscored the benefit of handwashing interventions.,Limited use of the Joint Monitoring Program's standardized water and sanitation definitions in the literature restricted efforts to generalize across studies.,While further research is warranted to determine the magnitude of benefit from WASH interventions for STH control, these results call for multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts.,Please see later in the article for the Editors' Summary,Worldwide, more than a billion people are infected with soil-transmitted helminths (STHs), parasitic worms that live in the human intestine (gut).,These intestinal worms, including roundworm, hookworm, and whipworm, mainly occur in tropical and subtropical regions and are most common in developing countries, where personal hygiene is poor, there is insufficient access to clean water, and sanitation (disposal of human feces and urine) is inadequate or absent.,STHs colonize the human intestine and their eggs are shed in feces and enter the soil.,Humans ingest the eggs, either by touching contaminated ground or eating unwashed fruit and vegetables grown in such soil.,Hookworm may enter the body by burrowing through the skin, most commonly when bare-footed individuals walk on infected soil.,Repeated infection with STHs leads to a heavy parasite infestation of the gut, causing chronic diarrhea, intestinal bleeding, and abdominal pain.,In addition the parasites compete with their human host for nutrients, leading to malnutrition, anemia, and, in heavily infected children, stunting of physical growth and slowing of mental development.,While STH infections can be treated in the short-term with deworming medication, rapid re-infection is common, therefore a more comprehensive program of improved water, sanitation, and hygiene (WASH) is needed.,WASH strategies include improvements in water access (e.g., water quality, water quantity, and distance to water), sanitation access (e.g., access to improved latrines, latrine maintenance, and fecal sludge management), and hygiene practices (e.g., handwashing before eating and/or after defecation, water treatment, soap use, wearing shoes, and water storage practices).,WASH strategies have been shown to be effective for reducing rates of diarrhea and other neglected tropical diseases, such as trachoma; however, there is limited evidence linking specific WASH access or practices to STH infection rates.,In this systematic review and meta-analysis, the researchers investigate whether WASH access or practices lower the risk of STH infections.,A systematic review uses predefined criteria to identify all the research on a given topic; a meta-analysis is a statistical method that combines the results of several studies.,The researchers identified 94 studies that included measurements of the relationship between WASH access and practices with one or more types of STHs.,Meta-analyses of the data from 35 of these studies indicated that overall people with access to WASH strategies or practices were about half as likely to be infected with any STH.,Specifically, a lower odds of infection with any STH was observed for those people who use treated water (odd ratio [OR] of 0.46), have access to sanitation (OR of 0.66), wear shoes (OR of 0.30), and use soap or have soap availability (OR of 0.53) compared to those without access to these practices or strategies.,In addition, infection with roundworm was less than half as likely in those who practiced handwashing both before eating and after defecating than those who did not practice handwashing (OR of 0.38 and 0.45, respectively).,The studies included in this systematic review and meta-analysis have several shortcomings.,For example, most were cross-sectional surveys-studies that examined the effect of WASH strategies on STH infections in a population at a single time point.,Given this study design, people with access to WASH strategies may have shared other characteristics that were actually responsible for the observed reductions in the risk of STH infections.,Consequently, the overall quality of the included studies was low and there was some evidence for publication bias (studies showing a positive association are more likely to be published than those that do not).,Nevertheless, these findings confirm that WASH access and practices provide an effective control measure for STH.,Controlling STHs in developing countries would have a huge positive impact on the physical and mental health of the population, especially children, therefore there should be more emphasis on expanding access to WASH as part of development guidelines and targets, in addition to short-term preventative chemotherapy currently used.,Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001620.,The US Centers for Disease Control and Prevention also provides detailed information on roundworm, whipworm, and hookworm infections,The World Health Organization provides information on soil-transmitted helminths, including a description of the current control strategy,Children Without Worms (CWW) partners with Johnson & Johnson, GlaxoSmithKline, the World Health Organization, national ministries of health and education, non-governmental organizations, and others to promote treatment and prevention of soil-transmitted helminthiasis.,CWW advocates a four-pronged, comprehensive control strategy-Water, Sanitation, Hygiene Education, and Deworming (WASHED) to break the cycle of reinfection,The Global Network for Neglected Tropical Diseases, an advocacy initiative dedicated to raising the awareness, political will, and funding necessary to control and eliminate the most common neglected tropical diseases, provides information on infections with roundworm (ascariasis), whipworm (trichuriasis), and hookworm,WASH for the Neglected Tropical Diseases is a repository of information on WASH and the neglected tropical diseases (NTDs) such as soil-transmitted helminthiasis, and features a resource titled “WASH and the NTDs: A Manual for WASH Implementers.”,Two international programs promoting water sanitation are the World Health Organization Water Sanitation and Health program and the World Health Organization/United Nations Childrens Fund Joint Monitoring Programme for Water Supply and Sanitation

Current first-line treatments for uncomplicated falciparum malaria rapidly clear the asexual stages of the parasite, but do not fully prevent parasite transmission by mosquitoes.,The standard membrane feeding assay (SMFA) is the biological gold standard assessment of transmission reducing activity (TRA), but its throughput is limited by the need to determine mosquito infection status by dissection and microscopy.,Here we present a novel dissection-free luminescence based SMFA format using a transgenic Plasmodium falciparum reporter parasite without resistance to known antimalarials and therefore unrestricted in its utility in compound screening.,Analyses of sixty-five compounds from the Medicines for Malaria Venture validation and malaria boxes identified 37 compounds with high levels of TRA (>80%); different assay modes allowed discrimination between gametocytocidal and downstream modes of action.,Comparison of SMFA data to published assay formats for predicting parasite infectivity indicated that individual in vitro screens show substantial numbers of false negatives.,These results highlight the importance of the SMFA in the screening pipeline for transmission reducing compounds and present a rapid and objective method.,In addition we present sixteen diverse chemical scaffolds from the malaria box that may serve as a starting point for further discovery and development of malaria transmission blocking drugs.

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.

Chagas disease is a major public health concern in Latin America and it is transmitted by insects of the subfamily Triatominae, including Rhodnius spp.,Since palm trees are ubiquitous in Colombia and a habitat for Rhodnius spp., the presence of palms near villages could increase contact rates between vectors and humans.,Therefore, knowing whether a relationship exists between the proximity of palms to villages and the abundance and distribution of vectors therein, may be critical for Chagas disease prevention programs.,Adapting a mathematical model for R. prolixus population dynamics in a small village, we model the implications of changing distances between palms and dwellings, to the risk of Chagas disease infection.,We implemented a mathematical model that reflects R. prolixus population dynamics in a small village located in the department of Casanare (Colombia) to study the role of palm-house proximity.,We varied the distance between palms and houses by monitoring the network global efficiency metric.,We constructed 1,000 hypothetical villages varying distances and each one was run 100 times.,According to the model, as palm-house proximity increases, houses were more likely to be visited by triatomine bugs.,The number of bugs per unit time increased progressively in a non-linear fashion with high variability.,We stress the importance of village configuration on the model output.,From a theoretical perspective, palm-house proximity may have a positive effect on the incidence of Chagas disease.,The model predicts a 1% increase in new human cases per year when houses and palms are brought closer by 75%.,The online version of this article (doi:10.1186/s13071-016-1884-8) contains supplementary material, which is available to authorized users.

Chagas disease has a major impact on human health in Latin America and is becoming of global concern due to international migrations.,Trypanosoma cruzi, the etiological agent of the disease, is one of the rare human parasites transmitted by the feces of its vector, as it is unable to reach the salivary gland of the insect.,This stercorarian transmission is notoriously poorly understood, despite its crucial role in the ecology and evolution of the pathogen and the disease.,The objective of this study was to quantify the probability of T. cruzi vectorial transmission to humans, and to use such an estimate to predict human prevalence from entomological data.,We developed several models of T. cruzi transmission to estimate the probability of transmission from vector to host.,Using datasets from the literature, we estimated the probability of transmission per contact with an infected triatomine to be 5.8×10−4 (95%CI: [2.6 ; 11.0]×10−4).,This estimate was consistent across triatomine species, robust to variations in other parameters, and corresponded to 900-4,000 contacts per case.,Our models subsequently allowed predicting human prevalence from vector abundance and infection rate in 7/10 independent datasets covering various triatomine species and epidemiological situations.,This low probability of T. cruzi transmission reflected well the complex and unlikely mechanism of transmission via insect feces, and allowed predicting human prevalence from basic entomological data.,Although a proof of principle study would now be valuable to validate our models' predictive ability in an even broader range of entomological and ecological settings, our quantitative estimate could allow switching the evaluation of disease risk and vector control program from purely entomological indexes to parasitological measures, as commonly done for other major vector borne diseases.,This might lead to different quantitative perspectives as these indexes are well known not to be proportional one to another.

Forty-five Schistosoma mansoni egg-negative/circulating cathodic antigen (CCA) low (Trace-1+) positive children in areas of very low prevalence were followed up daily for 30 days.,Stool and urine specimens were collected and examined each day from each child.,At the midpoint of the study, three egg-positive control persons with light intensity infection were included in the protocol.,Stool samples were examined by the Kato-Katz (four slides/stool sample) technique and all S. mansoni egg-negative stools were further tested by the “miracidia hatching test” (MHT).,Urine samples were examined by the point-of-care CCA assay (POC-CCA).,Over 30 days, only one of 1,338 consecutive stool samples from study subjects was S. mansoni egg and MHT positive (0.07%).,Egg counts fluctuated daily in stools from positive controls and S. mansoni miracidia were detected in all but two samples by the MHT.,Point-of-care-circulating cathodic antigen bands were scored from G1 to G10 and then translated to standard Trace, 1+, 2+, 3+ banding patterns.,In two districts, the POC-CCA assays were Trace or 1+ for both the study children and the positive controls.,In the third district, the POC-CCA assays were Trace or 1+ for the study children and 1+ or 2+ for the positive control.,We conclude that in areas with extremely low prevalence S. mansoni egg-negative and CCA-Trace or 1+ children are unlikely to pose substantial risks to continued transmission of schistosomiasis.,In this setting, POC-CCA Trace or 1+ readings are likely to be false positives or perhaps represent low-level single-sex schistosome infections.

Soil-transmitted helminths (STH) are the most common parasitic infections in impoverished communities, particularly among children.,Current STH control is through school-based mass drug administration (MDA), which in the Philippines is done twice annually.,As expected, MDA has decreased the intensity and prevalence of STH over time.,As a result, the common Kato Katz (KK) thick smear method of detecting STH is less effective because it lacks sensitivity in low intensity infections, making it difficult to measure the impact of deworming programs.,A cross-sectional study was carried out over a four-week period from October 27, 2014 until November 20, 2014 in Laguna province, the Philippines.,Stool samples were collected from 263 schoolchildren, to determine the prevalence of STH and compare diagnostic accuracy of multiplex quantitative polymerase chain reaction (qPCR) with the KK.,A large discrepancy in the prevalence between the two techniques was noted for the detection of at least one type of STH infection (33.8% by KK vs.,78.3% by qPCR), Ascaris lumbricoides (20.5% by KK vs.,60.8% by qPCR) and Trichuris trichiura (23.6% by KK vs.,38.8% by qPCR).,Considering the combined results of both methods, the prevalence of at least one type of helminth infection, A. lumbricoides, and T. trichiura were 83.3%, 67.7%, and 53.6%, respectively.,Sensitivity of the qPCR for detecting at least one type of STH infection, A. lumbricoides, and T. trichiura were 94.1%, 89.9%, and 72.3% respectively; whereas KK sensitivity was 40.6%, 30.3%, and 44.0%, respectively.,The qPCR method also detected infections with Ancylostoma spp.,(4.6%), Necator americanus (2.3%), and Strongyloides stercoralis (0.8%) that were missed by KK.,qPCR may provide new and important diagnostic information to improve assessment of the effectiveness and impact of integrated control strategies particularly in areas where large-scale STH control has led to low prevalence and/or intensity of infection.

Primaquine is essential for malaria control and elimination since it is the only available drug preventing multiple clinical attacks by relapses of Plasmodium vivax.,It is also the only therapy against the sexual stages of Plasmodium falciparum infectious to mosquitoes, and is thus useful in preventing malaria transmission.,However, the difficulties of diagnosing glucose-6-phosphate dehydrogenase deficiency (G6PDd) greatly hinder primaquine’s widespread use, as this common genetic disorder makes patients susceptible to potentially severe and fatal primaquine-induced haemolysis.,The risk of such an outcome varies widely among G6PD gene variants.,A literature review was conducted to identify surveys of G6PD variant frequencies among representative population groups.,Informative surveys were assembled into two map series: (1) those showing the relative proportions of the different variants among G6PDd individuals; and (2) those showing allele frequencies of G6PD variants based on population surveys without prior G6PDd screening.,Variants showed conspicuous geographic patterns.,A limited repertoire of variants was tested for across sub-Saharan Africa, which nevertheless indicated low genetic heterogeneity predominated by the G6PD A-202A mutation, though other mutations were common in western Africa.,The severe G6PD Mediterranean variant was widespread across western Asia.,Further east, a sharp shift in variants was identified, with high variant heterogeneity in the populations of China and the Asia-Pacific where no single variant dominated.,G6PD variants exhibited distinctive region-specific distributions with important primaquine policy implications.,Relative homogeneity in the Americas, Africa, and western Asia contrasted sharply with the heterogeneity of variants in China, Southeast Asia and Oceania.,These findings will inform rational risk assessments for primaquine in developing public health strategies for malaria control and elimination, and support the future development of regionally targeted policies.,The major knowledge gaps highlighted here strongly advocate for further investigation of G6PD variant diversity and their primaquine-sensitivity phenotypes.

Several studies have shown a prolonged or increased susceptibility to malaria in the post-partum period.,A matched cohort study was conducted to evaluate prospectively the susceptibility to malaria of post-partum women in an area where P.falciparum and P.vivax are prevalent.,In an area of low seasonal malaria transmission on the Thai-Myanmar border pregnant women attending antenatal clinics were matched to a non-pregnant, non-post-partum control and followed up prospectively until 12 weeks after delivery.,Post-partum women (n = 744) experienced significantly less P.falciparum episodes than controls (hazard ratio (HR) 0.39 (95%CI 0.21-0.72) p = 0.003) but significantly more P.vivax (HR 1.34 (1.05-1.72) p = 0.018).,The reduced risk of falciparum malaria was accounted for by reduced exposure, whereas a history of P.vivax infection during pregnancy was a strong risk factor for P.vivax in post-partum women (HR 13.98 (9.13-21.41), p<0.001).,After controlling for effect modification by history of P.vivax, post-partum women were not more susceptible to P.vivax than controls (HR: 0.33 (0.21-0.51), p<0.001).,Genotyping of pre-and post-partum infections (n⊕ = ⊕10) showed that each post-partum P.falciparum was a newly acquired infection.,In this area of low seasonal malaria transmission post-partum women were less likely to develop falciparum malaria but more likely to develop vivax malaria than controls.,This was explained by reduced risk of exposure and increased risk of relapse, respectively.,There was no evidence for altered susceptibility to malaria in the post-partum period.,The treatment of vivax malaria during and immediately after pregnancy needs to be improved.

A successful malaria control programme began in 2004 on Bioko Island, Equatorial Guinea.,From 2007, the same multiple malaria interventions, though reduced in scope for funding reasons, were introduced to the four mainland provinces of Equatorial Guinea (the continental region) aiming to recreate Bioko’s success.,Two provinces received long-lasting insecticidal nets (LLINs) and two provinces received biannual indoor residual spraying (IRS).,Enhanced case management and communications were introduced throughout.,Estimates of intervention coverage and indicators of malaria transmission for 2007 to 2011 were derived from annual malaria indicator surveys (MIS).,Results were complemented by health information system (HIS) and entomological data.,The personal protection offered by LLINs and IRS against Plasmodium falciparum infection was estimated with logistic regression.,The estimated proportion of children aged 1-4 using either an LLIN the previous night or living in a house sprayed in the last six months was 23% in 2007 and 42% in 2011.,The estimated prevalence of P. falciparum in children aged 1-4 was 68% (N=1,770; 95% confidence interval [CI]: 58-76%) in 2007 and 52% (N=1,602; 95% CI: 44-61%) in 2011.,Children 1-4 years had lower prevalence if they used an LLIN the previous night (N=1,124, 56%; adjusted odds ratio [aOR] 0.64, 95% CI: 0.55-0.74) or if they lived in a sprayed house (N=1,150, 57%; aOR 0.80, 95% CI: 0.62-1.03) compared to children with neither intervention (N=4,131, 66%, reference group).,The minority of children who both used an LLIN and lived in a sprayed house had the lowest prevalence of infection (N=171, 45%; aOR 0.52, 95% CI: 0.35-0.78).,High site-level intervention coverage did not always correlate with lower site-level P. falciparum prevalence.,The malaria season peaked in either June or July, not necessarily coinciding with MIS data collection.,Though moderate impact was achieved after five years of vector control, case management, and communications, prevalence remained high due to an inability to sufficiently scale-up coverage with either IRS or LLINs.,Both LLINs and IRS provided individual protection, but greater protection was afforded to children who benefitted from both.

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.

The impact of insecticide resistance in malaria vectors is poorly understood and quantified.,Here a series of geospatial datasets for insecticide resistance in malaria vectors are provided, so that trends in resistance in time and space can be quantified, and the impact of resistance found in wild populations on malaria transmission in Africa can be assessed.,Specifically, data have been collated and geopositioned for the prevalence of insecticide resistance, as measured by standard bioassays, in representative samples of individual species or species complexes.,Data are provided for the Anopheles gambiae species complex, the Anopheles funestus subgroup, and for nine individual vector species.,Data are also given for common genetic markers of resistance to support analyses of whether these markers can improve the ability to monitor resistance in low resource settings.,Allele frequencies for known resistance-associated markers in the Voltage-gated sodium channel (Vgsc) are provided.,In total, eight analysis-ready, standardised, geopositioned datasets encompassing over 20,000 African mosquito collections between 1957 and 2017 are released.

Progress in malaria control is under threat by wide-scale insecticide resistance in malaria vectors.,Two recent vector control products have been developed: a long-lasting insecticidal net that incorporates a synergist piperonyl butoxide (PBO) and a long-lasting indoor residual spraying formulation of the insecticide pirimiphos-methyl.,We evaluated the effectiveness of PBO long-lasting insecticidal nets versus standard long-lasting insecticidal nets as single interventions and in combination with the indoor residual spraying of pirimiphos-methyl.,We did a four-group cluster randomised controlled trial using a two-by-two factorial design of 48 clusters derived from 40 villages in Muleba (Kagera, Tanzania).,We randomly assigned these clusters using restricted randomisation to four groups: standard long-lasting insecticidal nets, PBO long-lasting insecticidal nets, standard long-lasting insecticidal nets plus indoor residual spraying, or PBO long-lasting insecticidal nets plus indoor residual spraying.,Both standard and PBO nets were distributed in 2015.,Indoor residual spraying was applied only once in 2015.,We masked the inhabitants of each cluster to the type of nets received, as well as field staff who took blood samples.,Neither the investigators nor the participants were masked to indoor residual spraying.,The primary outcome was the prevalence of malaria infection in children aged 6 months to 14 years assessed by cross-sectional surveys at 4, 9, 16, and 21 months after intervention.,The endpoint for assessment of indoor residual spraying was 9 months and PBO long-lasting insecticidal nets was 21 months.,This trial is registered with ClinicalTrials.gov, number NCT02288637.,7184 (68·0%) of 10 560 households were selected for post-intervention survey, and 15 469 (89·0%) of 17 377 eligible children from the four surveys were included in the intention-to-treat analysis.,Of the 878 households visited in the two indoor residual spraying groups, 827 (94%) had been sprayed.,Reported use of long-lasting insecticidal nets, across all groups, was 15 341 (77·3%) of 19 852 residents after 1 year, decreasing to 12 503 (59·2%) of 21 105 in the second year.,Malaria infection prevalence after 9 months was lower in the two groups that received PBO long-lasting insecticidal nets than in the two groups that received standard long-lasting insecticidal nets (531 [29%] of 1852 children vs 767 [42%] of 1809; odds ratio [OR] 0·37, 95% CI 0·21-0·65; p=0·0011).,At the same timepoint, malaria prevalence in the two groups that received indoor residual spraying was lower than in groups that did not receive indoor residual spraying (508 [28%] of 1846 children vs 790 [44%] of 1815; OR 0·33, 95% CI 0·19-0·55; p<0·0001) and there was evidence of an interaction between PBO long-lasting insecticidal nets and indoor residual spraying (OR 2·43, 95% CI 1·19-4·97; p=0·0158), indicating redundancy when combined.,The PBO long-lasting insecticidal net effect was sustained after 21 months with a lower malaria prevalence than the standard long-lasting insecticidal net (865 [45%] of 1930 children vs 1255 [62%] of 2034; OR 0·40, 0·20-0·81; p=0·0122).,The PBO long-lasting insecticidal net and non-pyrethroid indoor residual spraying interventions showed improved control of malaria transmission compared with standard long-lasting insecticidal nets where pyrethroid resistance is prevalent and either intervention could be deployed to good effect.,As a result, WHO has since recommended to increase coverage of PBO long-lasting insecticidal nets.,Combining indoor residual spraying with pirimiphos-methyl and PBO long-lasting insecticidal nets provided no additional benefit compared with PBO long-lasting insecticidal nets alone or standard long-lasting insecticidal nets plus indoor residual spraying.,UK Department for International Development, Medical Research Council, and Wellcome Trust.

Immunity to Plasmodium falciparum (Pf) malaria is only acquired after years of repeated infections and wanes rapidly without ongoing parasite exposure.,Antibodies are central to malaria immunity, yet little is known about the B-cell biology that underlies the inefficient acquisition of Pf-specific humoral immunity.,This year-long prospective study in Mali of 185 individuals aged 2 to 25 years shows that Pf-specific memory B-cells and antibodies are acquired gradually in a stepwise fashion over years of repeated Pf exposure.,Both Pf-specific memory B cells and antibody titers increased after acute malaria and then, after six months of decreased Pf exposure, contracted to a point slightly higher than pre-infection levels.,This inefficient, stepwise expansion of both the Pf-specific memory B-cell and long-lived antibody compartments depends on Pf exposure rather than age, based on the comparator response to tetanus vaccination that was efficient and stable.,These observations lend new insights into the cellular basis of the delayed acquisition of malaria immunity.

Plasmodium falciparum malaria causes 500 million clinical cases with approximately one million deaths each year.,After many years of exposure, individuals living in endemic areas develop a form of clinical immunity to disease known as premunition, which is characterised by low parasite burdens rather than sterilising immunity.,The reason why malaria parasites persist under a state of premunition is unknown but it has been suggested that suppression of protective immunity might be a mechanism leading to parasite persistence.,Although acquired immunity limits the clinical impact of infection and provides protection against parasite replication, experimental evidence indicates that cell-mediated immune responses also result in detrimental inflammation and contribute to the aetiology of severe disease.,Thus, an appropriate regulatory balance between protective immune responses and immune-mediated pathology is required for a favourable outcome of infection.,As natural regulatory T (Treg) cells are identified as an immunosuppressive lineage able to modulate the magnitude of effector responses, several studies have investigated whether this cell population plays a role in balancing protective immunity and pathogenesis during malaria.,The main findings to date are summarised in this review and the implication for the induction of pathogenesis and immunity to malaria is discussed.

In Zambia, there has been a large scaling up of interventions to control malaria in recent years including the deployment of rapid diagnostic tests (RDTs) to improve malaria surveillance data as well as guide malaria treatment in health facilities.,The practical challenge is the impact of RDT results on subsequent management of patients.,This study explored the role of RDTs in malaria diagnosis and the health workers’ adherence to test results.,An observational prospective study was carried out at health centres in four districts, namely Chibombo, Chingola, Chipata, and Choma.,Children under the age of five years with history of fever were recruited and the clinicians’ use of RDT results was observed to establish whether prescriptions were issued prior to the availability of parasitological results or after, and whether RDT results influenced their prescriptions.,Of the 2, 393 recruited children, 2, 264 had both RDT and microscopic results.,Two in three (68.6%) children were treated with anti-malarials despite negative RDT results and almost half (46.2%) of these were prescribed Coartem®.,Only 465 (19.4%) of the 2,393 children were prescribed drugs before receiving laboratory results.,A total of 76.5% children were prescribed drugs after laboratory results.,Children with RDT positive results were 2.66 (95% CI (2.00, 3.55)) times more likely to be prescribed anti-malarial drugs.,Children who presented with fever at admission (although history of fever or presence of fever at admission was an entry criterion) were 42% less likely to be prescribed an anti-malarial drug compared to children who had no fever (AOR = 0.58; 95% CI (0.52, 0.65)).,It was noted that proportions of children who were RDT- and microscopy-positive significantly declined over the years from 2005 to 2008.,RDTs may contribute to treatment of febrile illness by confirming malaria cases from non-malaria cases in children under the age of five.,However, the adherence of the health workers to prescribing anti-malarials to only RDT-positive cases at health facility level will still require to be explored further as their role is crucial in more precise reporting of malaria cases in this era towards malaria elimination as the target.

Effective and timely case management remains one of the fundamental pillars for control of malaria.,Tanzania introduced artemisinin-combination therapy [ACT] for uncomplicated malaria; however, the policy change is challenged by limited availability of ACTs due to high cost.,This study aimed to determine factors influencing prompt access to ACTs among febrile children in rural Kilosa, Tanzania.,In a community-based study, 1,235 randomly selected children under five were followed up weekly for six months, in 2008.,Using a structured questionnaire, children's caretakers were asked about the child's febrile history in the last seven days, and treatment actions including timing, medicines used and source of care.,Caretakers' knowledge about malaria and socioeconomic and demographic data were also obtained.,About half of followed-up children had at least one episode of fever.,Less than half (44.8%) of febrile children were taken to government facilities.,Almost one-third (37.6%; 95% CI 33.1-42.1) of febrile children had prompt access to ACT.,Care-seeking from a government facility was the overriding factor, increasing the likelihood of prompt access to an ACT 18 times (OR 17.7; 95% CI 10.55-29.54; adjusted OR 16.9; 95% CI 10.06-28.28).,Caretakers from the better-off household (3rd-5th quintiles) were more likely to seek care from government facilities (OR 3.66; 95% CI 2.56-5.24; adjusted OR 1.80; 95% CI 1.18-2.76).,The majority of antimalarials accessed by the poor were ineffective [86.0%; 295/343], however, they paid more for them (median Tsh 500) compared to the better-offs (median Tsh 0).,Prompt access to ACT among febrile children was unacceptably low, due mainly to limited availability of subsidised ACT at the location where most caretakers sought care.,There is urgent need to accelerate implementation of strategies that will ensure availability of ACT at an affordable price in remote rural areas, where the burden of malaria is highest.

Human cerebral malaria (HCM) is a severe form of malaria characterized by sequestration of infected erythrocytes (IRBCs) in brain microvessels, increased levels of circulating free heme and pro-inflammatory cytokines and chemokines, brain swelling, vascular dysfunction, coma, and increased mortality.,Neuregulin-1β (NRG-1) encoded by the gene NRG1, is a member of a family of polypeptide growth factors required for normal development of the nervous system and the heart.,Utilizing an experimental cerebral malaria (ECM) model (Plasmodium berghei ANKA in C57BL/6), we reported that NRG-1 played a cytoprotective role in ECM and that circulating levels were inversely correlated with ECM severity.,Intravenous infusion of NRG-1 reduced ECM mortality in mice by promoting a robust anti-inflammatory response coupled with reduction in accumulation of IRBCs in microvessels and reduced tissue damage.,In the current study, we examined how NRG-1 treatment attenuates pathogenesis and mortality associated with ECM.,We examined whether NRG-1 protects against CXCL10- and heme-induced apoptosis using human brain microvascular endothelial (hCMEC/D3) cells and M059K neuroglial cells. hCMEC/D3 cells grown in a monolayer and a co-culture system with 30 μM heme and NRG-1 (100 ng/ml) were used to examine the role of NRG-1 on blood brain barrier (BBB) integrity.,Using the in vivo ECM model, we examined whether the reduction of mortality was associated with the activation of ErbB4 and AKT and inactivation of STAT3 signaling pathways.,For data analysis, unpaired t test or one-way ANOVA with Dunnett’s or Bonferroni’s post test was applied.,We determined that NRG-1 protects against cell death/apoptosis of human brain microvascular endothelial cells and neroglial cells, the two major components of BBB.,NRG-1 treatment improved heme-induced disruption of the in vitro BBB model consisting of hCMEC/D3 and human M059K cells.,In the ECM murine model, NRG-1 treatment stimulated ErbB4 phosphorylation (pErbB4) followed by activation of AKT and inactivation of STAT3, which attenuated ECM mortality.,Our results indicate a potential pathway by which NRG-1 treatment maintains BBB integrity in vitro, attenuates ECM-induced tissue injury, and reduces mortality.,Furthermore, we postulate that augmenting NRG-1 during ECM therapy may be an effective adjunctive therapy to reduce CNS tissue injury and potentially increase the effectiveness of current anti-malaria therapy against human cerebral malaria (HCM).

Cerebral malaria (CM) is a disease of the vascular endothelium caused by Plasmodium falciparum.,It is characterized by parasite sequestration, inflammatory cytokine production, and vascular leakage.,A distinguishing feature of P. falciparum infection is parasite production and secretion of histidine-rich protein II (HRPII).,Plasma HRPII is a diagnostic and prognostic marker for falciparum malaria.,We demonstrate that disruption of a human cerebral microvascular endothelial barrier by P. falciparum-infected erythrocytes depends on expression of HRPII.,Purified recombinant or native HRPII can recapitulate these effects.,HRPII action occurs via activation of the inflammasome, resulting in decreased integrity of tight junctions and increased endothelial permeability.,We propose that HRPII is a virulence factor that may contribute to cerebral malaria by compromising endothelial barrier integrity within the central nervous system.,Cerebral malaria is a devastating disease.,Patients have high levels of the protein HRPII in their blood.,We have found that endothelial cell barriers become leaky when treated with concentrations of HRPII similar to those found in patients.,This result suggests that HRPII may be important in cerebral malaria.,Our finding that HRPII functions by causing inflammation suggests points of intervention for therapy or vaccination against this disease.

Despite its largely mountainous terrain for which this Himalayan country is a popular tourist destination, Nepal is now endemic for five major vector-borne diseases (VBDs), namely malaria, lymphatic filariasis, Japanese encephalitis, visceral leishmaniasis and dengue fever.,There is increasing evidence about the impacts of climate change on VBDs especially in tropical highlands and temperate regions.,Our aim is to explore whether the observed spatiotemporal distributions of VBDs in Nepal can be related to climate change.,A systematic literature search was performed and summarized information on climate change and the spatiotemporal distribution of VBDs in Nepal from the published literature until December2014 following providing items for systematic review and meta-analysis (PRISMA) guidelines.,We found 12 studies that analysed the trend of climatic data and are relevant for the study of VBDs, 38 studies that dealt with the spatial and temporal distribution of disease vectors and disease transmission.,Among 38 studies, only eight studies assessed the association of VBDs with climatic variables.,Our review highlights a pronounced warming in the mountains and an expansion of autochthonous cases of VBDs to non-endemic areas including mountain regions (i.e., at least 2,000 m above sea level).,Furthermore, significant relationships between climatic variables and VBDs and their vectors are found in short-term studies.,Taking into account the weak health care systems and difficult geographic terrain of Nepal, increasing trade and movements of people, a lack of vector control interventions, observed relationships between climatic variables and VBDs and their vectors and the establishment of relevant disease vectors already at least 2,000 m above sea level, we conclude that climate change can intensify the risk of VBD epidemics in the mountain regions of Nepal if other non-climatic drivers of VBDs remain constant.

Metabolic resistance to insecticides is the biggest threat to the continued effectiveness of malaria vector control.,However, its underlying molecular basis, crucial for successful resistance management, remains poorly characterized.,Here, we demonstrate that the single amino acid change L119F in an upregulated glutathione S-transferase gene, GSTe2, confers high levels of metabolic resistance to DDT in the malaria vector Anopheles funestus.,Genome-wide transcription analysis revealed that GSTe2 was the most over-expressed detoxification gene in DDT and permethrin-resistant mosquitoes from Benin.,Transgenic expression of GSTe2 in Drosophila melanogaster demonstrated that over-transcription of this gene alone confers DDT resistance and cross-resistance to pyrethroids.,Analysis of GSTe2 polymorphism established that the point mutation is tightly associated with metabolic resistance to DDT and its geographical distribution strongly correlates with DDT resistance patterns across Africa.,Functional characterization of recombinant GSTe2 further supports the role of the L119F mutation, with the resistant allele being more efficient at metabolizing DDT than the susceptible one.,Importantly, we also show that GSTe2 directly metabolizes the pyrethroid permethrin.,Structural analysis reveals that the mutation confers resistance by enlarging the GSTe2 DDT-binding cavity, leading to increased DDT access and metabolism.,Furthermore, we show that GSTe2 is under strong directional selection in resistant populations, and a restriction of gene flow is observed between African regions, enabling the prediction of the future spread of this resistance.,This first DNA-based metabolic resistance marker in mosquitoes provides an essential tool to track the evolution of resistance and to design suitable resistance management strategies.

Imported malaria in France is characterized by various clinical manifestations observed in a heterogeneous population of patients such as travelers/expatriates and African migrants.,In this population, host factors and parasite biomass associated with severe imported malaria are poorly known.,From data collected by the Centre National de Référence du Paludisme, we identified epidemiological, demographic and biological features including parasite biomass and anti-plasmodial antibody levels (negative, positive and strongly positive serology) associated with different disease severity groups (very severe, moderately severe, and uncomplicated malaria) in 3 epidemiological groups (travelers/expatriates, first- and second-generation migrants).,Age, ethnicity, absence of prior infection with P. falciparum, antibody levels, plasma PfHRP2 levels, total and circulating parasite biomass were related to severe malaria onset.,Sequestered parasite biomass tended to be increased in very severe malaria, and was strongly correlated to the antibody level of the host.,Prior exposure to P. falciparum is associated with high anti-plasmodial antibody levels which influence clinical presentation of imported malaria and its correlated circulating and sequestered parasite burden.

One hundred and twenty years ago, the Italian malariologists Marchiafava and Bignami proposed that the fundamental pathological process underlying lethal falciparum malaria was microvascular obstruction.,Since then, several alternative hypotheses have been proposed.,These formed the basis for adjunctive interventions, which have either been ineffective or harmful.,Recent evidence strongly suggests that Marchiafava and Bignami were right.

The malaria liver stage is an attractive target for antimalarial development, and preclinical malaria models are essential for testing such candidates.,Given ethical concerns and costs associated with non‐human primate models, humanized mouse models containing chimeric human livers offer a valuable alternative as small animal models of liver stage human malaria.,The best available human liver chimeric mice rely on cellular transplantation into mice with genetically engineered liver injury, but these systems involve a long and variable humanization process, are expensive, and require the use of breeding-challenged mouse strains which are not widely accessible.,We previously incorporated primary human hepatocytes into engineered polyethylene glycol (PEG)-based nanoporous human ectopic artificial livers (HEALs), implanted them in mice without liver injury, and rapidly generated human liver chimeric mice in a reproducible and scalable fashion.,By re-designing the PEG scaffold to be macroporous, we demonstrate the facile fabrication of implantable porous HEALs that support liver stage human malaria (P. falciparum) infection in vitro, and also after implantation in mice with normal liver function, 60% of the time.,This proof-of-concept study demonstrates the feasibility of applying a tissue engineering strategy towards the development of scalable preclinical models of liver stage malaria infection for future applications.

The development of an efficacious Plasmodium falciparum malaria vaccine remains a top priority for global health.,Vaccination with irradiated sporozoites is able to provide complete sterile protection through the action of CD8+ T cells at the liver-stage of infection.,However, this method is currently unsuitable for large-scale deployment and focus has instead turned to the development of sub-unit vaccines.,Sub-unit vaccine efforts have traditionally focused on two well-known pre-erythrocytic antigens, CSP and TRAP, yet thousands of genes are expressed in the liver-stage.,We sought to assess the ability of eight alternative P. falciparum pre-erythrocytic antigens to induce a high proportion of CD8+ T cells.,We show that all antigens, when expressed individually in the non-replicating viral vectors ChAd63 and MVA, are capable of inducing an immune response in mice.,Furthermore, we also developed chimeric P. berghei parasites expressing the cognate P. falciparum antigen to enable assessment of efficacy in mice.,Our preliminary results indicate that vectors encoding either PfLSA1 or PfLSAP2 are capable of inducing sterile protection dependent on the presence of CD8+ T cells.,This work has identified two promising P. falciparum liver-stage candidate antigens that will now undergo further testing in humans.

Zimbabwe conducts Malaria Indicator Surveys after 3 years and Demographic and Health Surveys to track the impact of malaria interventions.,The last one to be conducted was in 2016 and had set an aim aimed to collect data to track malaria indicators as well as to save as the baseline source for the Malaria Strategic Plan (2016-2020).,Malaria Indicator Survey-2016 utilized the frame of enumeration areas (EAs) from the Zimbabwe Master Sample (ZMS12) created after the 2012 population census for each of the survey districts.,The design for the survey was a representative probability sample to produce estimates at national level for the respective domains, which are the forty-four malaria-endemic districts.,Survey teams comprised of Ministry of Health personnel who administered the standard questionnaire (adapted to country setting) to respondents within sampled EAs, performed RDT, anaemia test, prepared microscopic slide and collected DBS and data analysis of collected information was analysed.,Microscopic slides examined centrally at the National Institute of Health Research.,The overall protection coverage by at least one major vector control measure, IRS and/or Nets, was 82.5%.,Use of nets among high-risk groups 32.5% For children under five and 24.5% for pregnant women.,LLIN utilization quite low taking into consideration the net ownership per household, which was 58% for the general population.,Moreover, IPTp coverage has remained almost unchanged since the 2012 MIS, with only a third of pregnant women receiving at least two doses of IPTp.,Malaria prevalence appears to be on the decline with 2016 MIS recording 0.2% compared to 0.4% as of 2012 MIS.,Plasmodium falciparum remains the predominant parasite species in the country at 98%.,The results indicated that some progress has been made in malaria control although there is still subsequent low malaria risk perception that comes with the reduced prevalence.,It has been shown that there is low use of interventions shown by the low use of LLINs by vulnerable groups like pregnant women and children under five.

This new resistance will have serious effects on malaria control.,Malaria control is dependent on insecticides.,Increases in prevalence of insecticide resistance in malaria vectors across Africa are well-documented.,However, few attempts have been made to quantify the strength of this resistance and link it to the effectiveness of control tools.,Using quantitative bioassays, we show that in Burkina Faso pyrethroid resistance in Anopheles gambiae mosquitoes has increased in intensity in recent years and now exceeds 1,000-fold.,In laboratory assays, this level of resistance renders insecticides used to impregnate bed nets ineffective.,Thus, the level of personal and community protection afforded by long-lasting insecticide-treated net campaigns will probably be reduced.,Standardized methods are needed to quantify resistance levels in malaria vectors and link these levels to failure of vector control methods.

To validate assumptions about the length of the distribution-replacement cycle for long-lasting insecticidal nets (LLINs) in Rwanda, the Malaria and other Parasitic Diseases Division, Rwanda Ministry of Health, used World Health Organization methods to independently confirm the three-year LLIN serviceable life span recommendation of WHO.,Approximately 3,000 coded LLINs, distributed as part of a national campaign, were monitored in six sites, by means of six-monthly visits to selected houses.,Two indicators, survivorship/attrition, a measure of the number of nets remaining, and fabric integrity, the proportion of remaining nets in either ‘good’, ‘serviceable’ or ‘needs replacement’ condition, based on holes in the net material, were tracked.,To validate the assumption that the intervention would remain effective for three years, LLIN coverage, calculated using either survivorship, or integrity, by removing nets in the ‘needs replacement’ category from the survivorship total, was compared with the predicted proportion of nets remaining, derived from a net loss model, that assumes an LLIN serviceable life of three years.,After two years, there was close agreement between estimated LLIN survivorship at all sites, 75% (range 64-84%), and the predicted proportion of nets remaining, 75%.,However, when integrity was considered, observed survivorship at all sites, declined to 42% (range 10-54%).,More than half, 58%, of the LLINs fell into the ‘needs replacement’ category after two years.,While these nets were counted for survivorship, they were judged to be of little-to-no benefit to a user.,Therefore, when integrity was taken into account, survivorship was significantly lower than predicted, suggesting that net serviceable life was actually closer to two, rather than three years, and, by extension, that the impact of the intervention during year three of the LLIN distribution-replacement cycle could be well below that seen in years one and two.

A huge discrepancy was reported between ownership versus utilization of insecticide-treated bed nets (ITNs).,To acquire the benefits of ITNs, households need to use and not merely own them.,The objective of this study was to characterize the pattern of, and assess factors related to ITN use in one village in south Ethiopia.,A prospective cohort study involving 8,121 residents (in 1,388 households) was carried out from April 2009 to April 2011 (101 weeks).,Every week, individuals were asked whether they slept under an ITN the night before the interview.,Descriptive statistics was used to report the availability and use of ITN.,A negative, binomial, probability, distribution model was fitted to find out significant predictors of ITN use.,Reasons for not using ITN were summarized.,The total number of ITNs available at the beginning of the study was 1,631 (1.68 ITNs per household).,On week 48, 3,099 new ITNs (PermaNet2.0) were distributed freely (2.3 ITNs per household).,The number of households who received at least one new ITN was 1,309 (98.4%).,The percentage of children <5 years and pregnant women not using ITNs exceeded that of other adults.,The mean (range; SD) ITN use fraction before and after mass distribution was 0.20 (0.15-0.27; 0.03) and 0.62 (0.47-0.69; 0.04), respectively.,Before mass ITN distribution, the most frequent reason for not using ITN was having worn out bed nets (most complained the bed nets were torn by rats); and after mass ITN distribution, it was lack of convenient space to hang more than one ITN.,Males, younger age groups (mainly 15-24 years) and those living away from the vector-breeding site were less likely to use ITN.,The ITN use fraction reached to a maximum of 69% despite near universal coverage (98.4%) was achieved.,Gender, age differences and distance from vector breeding site were associated with ITN use.,Strategies may need to be designed addressing disproportions in ITN use, lack of convenient space to hang more than one ITN (for those receiving more than one), and measures to prolong usable life of ITNs.

The mechanisms through which infection with Plasmodium spp. result in lung disease are largely unknown.,Recently a number of mouse models have been developed to research malaria-associated lung injury but no detailed ultrastructure studies of the disease in its terminal stages in a murine model have yet been published.,The goal was to perform an ultrastructural analysis of the lungs of mice that died with malaria-associated acute lung injury/acute respiratory distress syndrome to better determine the relevancy of the murine models and investigate the mechanism of disease.,DBA/2 mice were infected with Plasmodium berghei strain ANKA.,Mice had their lungs removed immediately after death, processed using standard methods and viewed by transmission electron microscopy (TEM).,Infected red blood cell:endothelium contact, swollen endothelium with distended cytoplasmic extensions and thickening of endothelium basement membrane were observed.,Septa were thick and filled with congested capillaries and leukocytes and the alveolar spaces contained blood cells, oedema and cell debris.,Results show that the lung ultrastructure of P. berghei ANKA-infected mice has similar features to what has been described in post-mortem TEM studies of lungs from individuals infected with Plasmodium falciparum.,These data support the use of murine models to study malaria-associated acute lung injury.

Cerebral malaria (CM) caused by Plasmodium falciparum is known to be associated with the sequestration of parasitized red blood cells (PRBCs) in the microvasculature and the release of soluble cytokines.,In addition, the involvement of signaling molecules has gained wide interest in the pathogenesis of CM.,An important signaling factor, nuclear factor kappa B (NF-κB) is known to regulate apoptosis.,This work aimed to study the expression of NF-κB p65 and its correlation with apoptosis in the brain of fatal CM.,The expression of NF-κB p65 and cleaved caspase-3 in the brain of fatal P. falciparum malaria cases was investigated by immunohistochemistry.,Histopathological features were analysed together with the correlations of NF-κB p65 and cleaved caspase-3 expression.,NF-κB p65 activation and cleaved caspase-3 expression were significantly increased in the neurons, glial cells, vascular endothelial cells (ECs) and intravascular leukocytes of the brain in fatal CM, compared with the control brain (p < 0.001) and non-cerebral malaria (NCM) (p = 0.034).,The percentage of neurons that expressed nuclear NF-κB p65 showed a positive correlation with the total score of histopathological changes (rs = 0.678; p = 0.045).,Significant positive correlations were established between vascular ECs NF-κB index and ECs apoptotic index (rs = 0.717; p = 0.030) and between intravascular leukocytes NF-κB index and leukocytes apoptotic index (rs = 0.696; p = 0.037) in fatal CM.,This study documented that NF-κB p65 is one of the signaling factors that modulates apoptosis in the brain ECs and intravascular leukocytes of fatal CM.

An increasing risk of Schistosoma mansoni infection has been observed around Lake Victoria, western Kenya since the 1970s.,Understanding local transmission dynamics of schistosomiasis is crucial in curtailing increased risk of infection.,We carried out a cross sectional study on a population of 310 children from eight primary schools.,Overall, a total of 238 (76.8%) children were infected with S. mansoni, while seven (2.3%) had S. haematobium.,The prevalence of hookworm, Trichuris trichiura and Ascaris lumbricoides were 6.1%, 5.2% and 2.3%, respectively.,Plasmodium falciparum was the only malaria parasite detected (12.0%).,High local population density within a 1 km radius around houses was identified as a major independent risk factor of S. mansoni infection.,A spatial cluster of high infection risk was detected around the Mbita causeway following adjustment for population density and other potential risk factors.,Population density was shown to be a major factor fuelling schistosome infection while individual socio-economic factors appeared not to affect the infection risk.,The high-risk cluster around the Mbita causeway may be explained by the construction of an artificial pathway that may cause increased numbers of S. mansoni host snails through obstruction of the waterway.,This construction may have, therefore, a significant negative impact on the health of the local population, especially school-aged children who frequently come in contact with lake water.

Schistosoma mansoni and S. haematobium are co-endemic in many areas in Africa.,Yet, little is known about the micro-geographical distribution of these two infections or associated disease within such foci.,Such knowledge could give important insights into the drivers of infection and disease and as such better tailor schistosomiasis control and elimination efforts.,In a co-endemic farming community in northern Senegal (346 children (0-19 y) and 253 adults (20-85 y); n = 599 in total), we studied the spatial distribution of S. mansoni and S. haematobium single and mixed infections (by microscopy), S. mansoni-specific hepatic fibrosis, S. haematobium-specific urinary tract morbidity (by ultrasound) and water contact behavior (by questionnaire).,The Kulldorff's scan statistic was used to detect spatial clusters of infection and morbidity, adjusted for the spatial distribution of gender and age.,Schistosoma mansoni and S. haematobium infection densities clustered in different sections of the community (p = 0.002 and p = 0.023, respectively), possibly related to heterogeneities in the use of different water contact sites.,While the distribution of urinary tract morbidity was homogeneous, a strong geospatial cluster was found for severe hepatic fibrosis (p = 0.001).,Particularly those people living adjacent to the most frequently used water contact site were more at risk for more advanced morbidity (RR = 6.3; p = 0.043).,Schistosoma infection and associated disease showed important micro-geographical heterogeneities with divergent patterns for S. mansoni and S. haematobium in this Senegalese community.,Further in depth investigations are needed to confirm and explain our observations.,The present study indicates that local geospatial patterns should be taken into account in both research and control of schistosomiasis.,The observed extreme focality of schistosomiasis even at community level, suggests that current strategies may not suffice to move from morbidity control to elimination of schistosomiasis, and calls for less uniform measures at a finer scale.

Malaria is reportedly receding in different epidemiological settings, but local long-term surveys are limited.,At Mlomp dispensary in south-western Senegal, an area of moderate malaria transmission, year-round, clinically-suspected malaria was treated with monotherapy as per WHO and national policy in the 1990s.,Since 2000, there has been a staggered deployment of artesunate-amodiaquine after parasitological confirmation; this was adopted nationally in 2006.,Data were extracted from clinic registers for the period between January 1996 and December 2010, analysed and modelled.,Over the 15-year study period, the risk of malaria decreased about 32-times (from 0.4 to 0.012 episodes person-year), while anti-malarial treatments decreased 13-times (from 0.9 to 0.07 treatments person-year) and consultations for fever decreased 3-times (from 1.8 to 0.6 visits person-year).,This was paralleled by changes in the age profile of malaria patients so that the risk of malaria is now almost uniformly distributed throughout life, while in the past malaria used to concern more children below 16 years of age.,This study provides direct evidence of malaria risk receding between 1996-2010 and becoming equal throughout life where transmission used to be moderate.,Infection rates are no longer enough to sustain immunity.,Temporally, this coincides with deploying artemisinin combinations on parasitological confirmation, but other contributing causes are unclear.

Objective To test in West Africa the impact of rapid diagnostic tests on the prescription of antimalarials and antibiotics both where microscopy is used for the diagnosis of malaria and in clinical (peripheral) settings that rely on clinical diagnosis.,Design Randomised, controlled, open label clinical trial.,Setting Four clinics in the rural Dangme West district of southern Ghana, one in which microscopy is used for diagnosis of malaria (“microscopy setting”) and three where microscopy is not available and diagnosis of malaria is made on the basis of clinical symptoms (“clinical setting”).,Participants Patients with suspected malaria.,Interventions Patients were randomly assigned to either a rapid diagnostic test or the current diagnostic method at the clinic (microscopy or clinical diagnosis).,A blood sample for a research microscopy slide was taken for all patients.,Main outcome measures The primary outcome was the prescription of antimalarials to patients of any age whose double read research slide was negative for malaria.,The major secondary outcomes were the correct prescription of antimalarials, the impact of test results on antibiotic prescription, and the correct prescription of antimalarials in children under 5 years.,Results Of the 9236 patients screened, 3452 were randomised in the clinical setting and 3811 in the microscopy setting.,Follow-up to 28 days was 97.6% (7088/7263).,In the microscopy setting, 722 (51.6%) of the 1400 patients with negative research slides in the rapid diagnostic test arm were treated for malaria compared with 764 (55.0%) of the 1389 patients in the microscopy arm (adjusted odds ratio 0.87, 95% CI 0.71 to 1.1; P=0.16).,In the clinical setting, 578 (53.9%) of the 1072 patients in the rapid diagnostic test arm with negative research slides were treated for malaria compared with 982 (90.1%) of the 1090 patients with negative slides in the clinical diagnosis arm (odds ratio 0.12, 95% CI 0.04 to 0.38; P=0.001).,The use of rapid diagnostic tests led to better targeting of antimalarials and antibiotics in the clinical but not the microscopy setting, in both children and adults.,There were no deaths in children under 5 years at 28 days follow-up in either arm.,Conclusion Where microscopy already exists, introducing rapid diagnostic tests had limited impact on prescriber behaviour.,In settings where microscopy was not available, however, using rapid diagnostic tests led to a significant reduction in the overprescription of antimalarials, without any evidence of clinical harm, and to better targeting of antibiotics.,Trial registration ClinicalTrials.gov NCT00493922.

Leishmaniasis is a vector-borne neglected tropical disease that affects more than 700,000 people annually.,Leishmania parasites cause the disease, and different species trigger a distinct immune response and clinical manifestations.,Macrophages are the final host cells for the proliferation of Leishmania parasites, and these cells are the key to a controlled or exacerbated response that culminates in clinical manifestations.,M1 and M2 are the two main macrophage phenotypes.,M1 is a pro-inflammatory subtype with microbicidal properties, and M2, or alternatively activated, is an anti-inflammatory/regulatory subtype that is related to inflammation resolution and tissue repair.,The present review elucidates the roles of M1 and M2 polarization in leishmaniasis and highlights the role of the salivary components of the vector and the action of the parasite in the macrophage plasticity.

The determinants of parasite persistence or elimination after treatment and clinical resolution of cutaneous leishmaniasis (CL) are unknown.,We investigated clinical and parasitological parameters associated with the presence and viability of Leishmania after treatment and resolution of CL caused by L.,Viannia.,Seventy patients who were treated with meglumine antimoniate (n = 38) or miltefosine (n = 32) and cured, were included in this study.,Leishmania persistence and viability were determined by detection of kDNA and 7SLRNA transcripts, respectively, before, at the end of treatment (EoT), and 13 weeks after initiation of treatment in lesions and swabs of nasal and tonsillar mucosa.,Sixty percent of patients (42/70) had evidence of Leishmania persistence at EoT and 30% (9/30) 13 weeks after treatment initiation.,A previous episode of CL was found to be a protective factor for detectable Leishmania persistence (OR: 0.16, 95%CI: 0.03-0.92). kDNA genotyping could not discern differences between parasite populations that persisted and those isolated at diagnosis.,Leishmania persist in skin and mucosal tissues in a high proportion of patients who achieved therapeutic cure of CL.,This finding prompts assessment of the contribution of persistent infection in transmission and endemicity of CL, and in disease reactivation and protective immunity.

CD43 (leukosialin) is a large sialoglycoprotein abundantly expressed on the surface of most cells from the hematopoietic lineage.,CD43 is directly involved in the contact between cells participating in a series of events such as signaling, adherence and host parasite interactions.,In this study we examined the role of CD43 in the immune response against Trypanosoma cruzi, the protozoan parasite that causes Chagas’ disease, a potential life-threatening illness endemic in 21 Latin American countries according to the WHO.,The acute stage of infection is marked by intense parasitemia and cardiac tissue parasitism, resulting in the recruitment of inflammatory cells and acute damage to the heart tissue.,We show here that CD43−/− mice were more resistant to infection due to increased cytotoxicity of antigen specific CD8+ T cells and reduced inflammatory infiltration in the cardiac tissue, both contributing to lower cardiomyocyte damage.,In addition, we demonstrate that the induction of acute myocarditis involves the engagement of CD43 cytoplasmic tripeptide sequence KRR to ezrin-radixin-moiesin cytoskeletal proteins.,Together, our results show the participation of CD43 in different events involved in the pathogenesis of T. cruzi infection, contributing to a better overall understanding of the mechanisms underlying the pathogenesis of acute chagasic cardiomyopathy.

Exosomes are 30-100-nm membrane vesicles of endocytic origin that are released after the fusion of multivesicular bodies (MVBs) with the plasma membrane.,While initial studies suggested that the role of exosomes was limited to the removal of proteins during the maturation of reticulocytes to erythrocytes, recent studies indicate that they are produced by different types of cells and are involved in promoting inter-cellular communication and antigen presentation.,Here, we describe the isolation and characterization of exosomes from peripheral blood of BALB/c mice infected with the reticulocyte-prone non-lethal Plasmodium yoelii 17X strain.,Importantly, proteomic analysis revealed the presence of parasite proteins in these vesicles.,Moreover, immunization of mice with purified exosomes elicited IgG antibodies capable of recognizing P. yoelii-infected red blood cells.,Furthermore, lethal challenge of immunized mice with the normocyte-prone lethal P. yoelii 17XL strain caused a significant attenuation in the course of parasitaemia, increased survival time, and altered the cell tropism to reticulocytes.,These results were obtained also when the exosomes were isolated from a P. yoelii-infected reticulocyte culture indicating that reticulocyte-derived exosomes carry antigens and are involved in immune modulation.,Moreover, inclusion of CpG ODN 1826 in exosome immunizations elicited IgG2a and IgG2b antibodies and promoted survival, clearance of parasites and subsequent sterile protection of 83% of the animals challenged with P. yoelli 17XL.,To our knowledge, this is the first report of immune responses elicited by exosomes derived from reticulocytes opening new avenues for the modulation of anti-malaria responses.

More than a century after the discovery of Plasmodium spp. parasites, the pathogenesis of severe malaria is still not well understood.,The majority of malaria cases are caused by Plasmodium falciparum and Plasmodium vivax, which differ in virulence, red blood cell tropism, cytoadhesion of infected erythrocytes, and dormant liver hypnozoite stages.,Cerebral malaria coma is one of the most severe manifestations of P. falciparum infection.,Insights into its complex pathophysiology are emerging through a combination of autopsy, neuroimaging, parasite binding, and endothelial characterizations.,Nevertheless, important questions remain regarding why some patients develop life-threatening conditions while the majority of P. falciparum-infected individuals do not, and why clinical presentations differ between children and adults.,For P. vivax, there is renewed recognition of severe malaria, but an understanding of the factors influencing disease severity is limited and remains an important research topic.,Shedding light on the underlying disease mechanisms will be necessary to implement effective diagnostic tools for identifying and classifying severe malaria syndromes and developing new therapeutic approaches for severe disease.,This review highlights progress and outstanding questions in severe malaria pathophysiology and summarizes key areas of pathogenesis research within the International Centers of Excellence for Malaria Research program.

Sequence diversity in pathogen antigens is an obstacle to the development of interventions against many infectious diseases.,In malaria caused by Plasmodium falciparum, the PfEMP1 family of variant surface antigens encoded by var genes are adhesion molecules that play a pivotal role in malaria pathogenesis and clinical disease.,PfEMP1 is a major target of protective immunity, however, development of drugs or vaccines based on PfEMP1 is problematic due to extensive sequence diversity within the PfEMP1 family.,Here we identified the PfEMP1 variants transcribed by P. falciparum strains selected for a virulence-associated adhesion phenotype (IgM-positive rosetting).,The parasites transcribed a subset of Group A PfEMP1 variants characterised by an unusual PfEMP1 architecture and a distinct N-terminal domain (either DBLα1.5 or DBLα1.8 type).,Antibodies raised in rabbits against the N-terminal domains showed functional activity (surface reactivity with live infected erythrocytes (IEs), rosette inhibition and induction of phagocytosis of IEs) down to low concentrations (<10 µg/ml of total IgG) against homologous parasites.,Furthermore, the antibodies showed broad cross-reactivity against heterologous parasite strains with the same rosetting phenotype, including clinical isolates from four sub-Saharan African countries that showed surface reactivity with either DBLα1.5 antibodies (variant HB3var6) or DBLα1.8 antibodies (variant TM284var1).,These data show that parasites with a virulence-associated adhesion phenotype share IE surface epitopes that can be targeted by strain-transcending antibodies to PfEMP1.,The existence of shared surface epitopes amongst functionally similar disease-associated P. falciparum parasite isolates suggests that development of therapeutic interventions to prevent severe malaria is a realistic goal.

Tanzania has seen a reduction in the fraction of fevers caused by malaria, likely due in part to scale-up of control measures.,While national guidelines require parasite-based diagnosis prior to treatment, it is estimated that more than half of suspected malaria treatment-seeking in Tanzania initiates in the private retail sector, where diagnosis by malaria rapid diagnostic test (RDT) or microscopy is illegal.,This pilot study investigated whether the introduction of RDTs into Accredited Drug Dispensing Outlets (ADDOs) under realistic market conditions would improve case management practices.,Dispensers from ADDOs in two intervention districts in Tanzania were trained to stock and perform RDTs and monitored quarterly.,Each district was assigned a different recommended retail price to evaluate the need for a subsidy.,Malaria RDT and artemisinin-based combination therapy (ACT) uptake and availability were measured pre-intervention and 1 year post-intervention through structured surveys of ADDO owners and exiting customers in both intervention districts and one contiguous control district.,Descriptive analysis and logistic regression were used to compare the three districts and identify predictive variables for testing.,A total of 310 dispensers from 262 ADDOs were trained to stock and perform RDTs.,RDT availability in intervention ADDOs increased from 1% (n = 172) to 73% (n = 163) during the study; ACT medicines were available in 75% of 260 pre-intervention and 68% of 254 post-intervention ADDOs.,Pre-treatment testing performed within the ADDO increased from 0 to 65% of suspected malaria patients who visited a shop (95% CI 60.8-69.6%) with no difference between intervention districts.,Overall parasite-based diagnosis increased from 19 to 74% in intervention districts and from 3 to 18% in the control district.,Prior knowledge of RDT availability (aOR = 1.9, p = 0.03) and RDT experience (aOR = 1.9, p = 0.01) were predictors for testing.,Adherence data indicated that 75% of malaria positives received ACT, while 3% of negatives received ACT.,Trained and supervised ADDO dispensers in rural Tanzania performed and sold RDTs under real market conditions to two-thirds of suspected malaria patients during this one-year pilot.,These results support the hypothesis that introducing RDTs into regulated private retail sector settings can improve malaria testing and treatment practices without an RDT subsidy.,Trial registration ISRCTN ISRCTN14115509

Malaria treatment policy recommends regular monitoring of drug utilization to generate information for ensuring effective use of anti-malarial drugs in Nigeria.,This information is currently limited in the retail sector which constitutes a major source of malaria treatment in Nigeria, but are characterized by significant inappropriate use of drugs.,This study analyzed the use pattern of anti-malarial drugs in medicine outlets to assess the current state of compliance to policy on the use of artemisinin-based combination therapy (ACT).,A prospective cross-sectional survey of randomly selected medicine outlets in Enugu urban, southeast Nigeria, was conducted between May and August 2013, to determine the types, range, prices, and use pattern of anti-malarial drugs dispensed from pharmacies and patent medicine vendors (PMVs).,Data were collected and analyzed for anti-malarial drugs dispensed for self-medication to patients, treatment by retail outlets and prescription from hospitals.,A total of 1,321 anti-malarial drugs prescriptions were analyzed.,ACT accounted for 72.7%, while monotherapy was 27.3%.,Affordable Medicines Facility-malaria (AMFm) drugs contributed 33.9% (326/961) of ACT.,Artemether-lumefantrine (AL), 668 (50.6%) was the most used anti-malarial drug, followed by monotherapy sulphadoxine-pyrimethamine (SP), 248 (18.8%).,Median cost of ACT at $2.91 ($0.65-7.42) per dose, is about three times the median cost of monotherapy, $0.97 ($0.19-13.55).,Total cost of medication (including co-medications) with ACT averaged $3.64 (95% CI; $3.53-3.75) per prescription, about twice the mean cost of treatment with monotherapy, $1.83 (95% CI; $1.57-2.1).,Highest proportion 46.5% (614), of the anti-malarial drugs was dispensed to patients for self-treatment.,Treatment by retail outlets accounted for 35.8% while 17.7% of the drugs were dispensed from hospital prescriptions.,Self-medication, 82%, accounted for the highest source of monotherapy and a majority of prescriptions, 85.6%, was adults.,Findings suggest vastly improved use of ACT in the retail sector after eight years of policy change, with significant contributions from AMFm drugs.,However the use of monotherapy, particularly through self-medication remains significant with increasing risk of undermining treatment policy, suggesting additional measures to directly target consumers and providers in the sector for improved use of anti-malarial drugs in Nigeria.

Hookworm infections are rare causes of acute gastrointestinal bleeding.,We report a middle aged man with primary nephrotic syndrome and pulmonary embolism.,During the treatment with steroids and anticoagulants, the patient presented acute massive hemorrhage of the gastrointestinal tract.,The results of gastroscopy showed red worms in the duodenum.,Colonoscopy and CT angiogram of abdomen were unremarkable.,Capsule endoscopy revealed fresh blood and multiple hookworms in the jejunum and ileum.,Hookworms caused the acute intestinal bleeding.,The patient responded well to albendazole.,Hematochezia was markedly ameliorated after eliminating the parasites.,Hence, hookworm infection should be considered in the differential diagnosis of a patient with obscure gastrointestinal bleeding.,Capsule endoscopy may offer a better means of diagnosis for intestinal hookworm infections.

Plasmodium vivax is responsible for a significant portion of malaria cases worldwide, especially in Asia and Latin America, where geo-helminthiasis have a high prevalence.,Impact of the interaction between vivax malaria and intestinal helminthes has been poorly explored.,The objective of this study was to evaluate the influence of intestinal helminthiasis on the concentration of hemoglobin in children with Plasmodium vivax malaria in rural areas in the municipality of Careiro, in the Western Brazilian Amazon.,A cohort study was conducted from April to November 2008, enrolling children from 5 to 14 years old in two rural areas endemic for malaria.,A cross-sectional evaluation was performed in April to actively detect cases of malaria and document baseline hemoglobin and nutritional status.,Children were followed-up for six months through passive case detection of malaria based on light microscopy.,Throughout the follow-up interval, hemoglobin value and stool examination (three samples on alternate days) were performed on children who developed P. vivax malaria.,For 54 schoolchildren with a single infection by P. vivax, hemoglobin during the malaria episode was similar to the baseline hemoglobin for children co-infected with Ascaris lumbricoides (n = 18), hookworm (n = 11) and Trichuris trichiura (n = 9).,In children without intestinal helminthes, a significant decrease in the hemoglobin during the malarial attack was seen as compared to the baseline concentration.,In the survival analysis, no difference was seen in the time (in days) from the baseline cross-sectional to the first malarial infection, between parasitized and non-parasitized children.,For the first time, a cohort study showed that intestinal helminthes protect against hemoglobin decrease during an acute malarial attack by P. vivax.

Policy makers, governments and donors are faced with an information gap when considering ways to improve access to artemisinin-based combination therapy (ACT) and malaria diagnostics including rapid diagnostic tests (RDTs).,To help address some of these gaps, a five-year multi-country research project called ACTwatch was launched.,The project is designed to provide a comprehensive picture of the anti-malarial market to inform national and international anti-malarial drug policy decision-making.,The project is being conducted in seven malaria-endemic countries: Benin, Cambodia, the Democratic Republic of Congo, Madagascar, Nigeria, Uganda and Zambia from 2008 to 2012.,ACTwatch measures which anti-malarials are available, where they are available and at what price and who they are used by.,These indicators are measured over time and across countries through three study components: outlet surveys, supply chain studies and household surveys.,Nationally representative outlet surveys examine the market share of different anti-malarials passing through public facilities and private retail outlets.,Supply chain research provides a picture of the supply chain serving drug outlets, and measures mark-ups at each supply chain level.,On the demand side, nationally representative household surveys capture treatment seeking patterns and use of anti-malarial drugs, as well as respondent knowledge of anti-malarials.,The research project provides findings on both the demand and supply side determinants of anti-malarial access.,There are four key features of ACTwatch.,First is the overlap of the three study components where nationally representative data are collected over similar periods, using a common sampling approach.,A second feature is the number and diversity of countries that are studied which allows for cross-country comparisons.,Another distinguishing feature is its ability to measure trends over time.,Finally, the project aims to disseminate findings widely for decision-making.,ACTwatch is a unique multi-country research project that threads together anti-malarial supply and consumer behaviour to provide an evidence base to policy makers that can help determine where interventions may positively impact access to and use of quality-assured ACT and RDTs.,Because of its ability to detect change over time, it is well suited to monitor the effects of policy or intervention developments in a country.

Whilst some populations have recently experienced dramatic declines in malaria, the majority of those most at risk of Plasmodium falciparum malaria still lack access to effective treatment with artemisinin combination therapy (ACT) and others are already facing parasites resistant to artemisinins.,In this context, there is a crucial need to improve both access to and targeting of ACT through greater availability of good quality ACT and parasitological diagnosis.,This is an issue of increasing urgency notably in the private commercial sector, which, in many countries, plays an important role in the provision of malaria treatment.,The Affordable Medicines Facility for malaria (AMFm) is a recent initiative that aims to increase the provision of affordable ACT in public, private and NGO sectors through a manufacturer-level subsidy.,However, to date, there is little documented experience in the programmatic implementation of subsidized ACT in the private sector.,Cambodia is in the unique position of having more than 10 years of experience not only in implementing subsidized ACT, but also rapid diagnostic tests (RDT) as part of a nationwide social marketing programme.,The programme includes behaviour change communication and the training of private providers as well as the sale and distribution of Malarine, the recommended ACT, and Malacheck, the RDT.,This paper describes and evaluates this experience by drawing on the results of household and provider surveys conducted since the start of the programme.,The available evidence suggests that providers' and consumers' awareness of Malarine increased rapidly, but that of Malacheck much less so.,In addition, improvements in ACT and RDT availability and uptake were relatively slow, particularly in more remote areas.,The lack of standardization in the survey methods and the gaps in the data highlight the importance of establishing a clear system for monitoring and evaluation for similar initiatives.,Despite these limitations, a number of important lessons can still be learnt.,These include the importance of a comprehensive communications strategy and of a sustained and reliable supply of products, with attention to the geographical reach of both.,Other important challenges relate to the difficulty in incentivising providers and consumers not only to choose the recommended drug, but to precede this with a confirmatory blood test and ensure that providers adhere to the test results and patients to the treatment regime.,In Cambodia, this is particularly complicated due to problems inherent to the drug itself and the emergence of artemisinin resistance.

Neospora caninum, a protozoan parasite closely related to Toxoplasma gondii, represents one of the main causes of abortion in cattle.,Macrophages (MØs) are mediators of the innate immune response against infection and likely one of the first cells encountered by the parasite during the host infection process.,In this study, we investigated in vitro how high or low virulent isolates of N. caninum (Nc-Spain7 and Nc-Spain1H, respectively) interact with bovine monocyte-derived MØs and the influence of the isolate virulence on the subsequent cellular response.,Both isolates actively invaded, survived and replicated in the MØs.,However, Nc-Spain7 showed a higher invasion rate and a replication significantly faster, following an exponential growth model, whereas Nc-Spain1H presented a delayed replication and a lower growth rate without an exponential pattern.,N. caninum infection induced a hypermigratory phenotype in bovine MØs that was characterized by enhanced motility and transmigration in vitro and was accompanied by morphological changes and abrogated extracellular matrix degradation.,A significantly higher hypermotility was observed with the highly virulent isolate Nc-Spain7.,Nc-Spain1H-infected MØs showed elevated reactive oxygen species (ROS) production and IL12p40 expression, which also resulted in increased IFN-γ release by lymphocytes, compared to cells infected with Nc-Spain7.,Furthermore, IL-10 was upregulated in MØs infected with both isolates.,Infected MØs exhibited lower expression of MHC Class II, CD86, and CD1b molecules than uninfected MØs, with non-significant differences between isolates.,This work characterizes for the first time N. caninum replication in bovine monocyte-derived MØs and details isolate-dependent differences in host cell responses to the parasite.

Ectopic secondary lymph follicles emerge in patients with autoimmune or infectious diseases, e.g. in the synovium in rheumatoid arthritis or the skin in Borrelia burgdorferi infection, but ectopic localisations in the skin are rarely described for helminth infections.,We investigated the cellular composition of secondary lymph follicles in subcutaneous nodules from eight patients with hyperreactive onchocerciasis (synonymous “localised” form or sowda) using immunohistology.,CD3- and CD45RO-positive T cells and CD20-positive B cells were present in the mantle zone.,The germinal centre was characterised by many B cells and CD35-positive follicular dendritic cells, which formed a network of attached IgE- and CD23-positive cells with the low-affinity IgE (epsilon) receptor.,Few of the B cells were labelled for IgG1, IgG2 and IgG4, whereas in other zones of the nodule IgG1 was expressed by plasma cells and IgG1-coated dead microfilariae.,B cells and few macrophages expressed the MHC class II molecule HLA-DR.,Mature CD68-positive tingible body macrophages with phagocytosed leukocytes and CD57-positive lymphocytes occurred in the germinal centre.,Macrophages in the germinal centre only weakly expressed alpha1-antichymotrypsin in contrast to macrophages in other zones of the onchocercoma.,Furthermore, the multifunctional cytokine TGF-beta was only weakly expressed by macrophages and lymphocytes in the secondary follicles.,Only few tryptase-positive mast cells, calprotectin-positive young macrophages, eosinophils and neutrophils occurred in the secondary follicles, although these cells were abundant in the onchocercomas.,In conclusion, the ectopic secondary lymph follicles in onchocercomas and lymph nodes from hyperreactive onchocerciasis patients are equally composed.,The online version of this article (doi:10.1007/s00436-010-1912-0) contains supplementary material, which is available to authorized users.

Visceral leishmaniasis (VL) is characterised by a high degree of spatial clustering at all scales, and this feature remains even with successful control measures.,VL is targeted for elimination as a public health problem in the Indian subcontinent by 2020, and incidence has been falling rapidly since 2011.,Current control is based on early diagnosis and treatment of clinical cases, and blanket indoor residual spraying of insecticide (IRS) in endemic villages to kill the sandfly vectors.,Spatially targeting active case detection and/or IRS to higher risk areas would greatly reduce costs of control, but its effectiveness as a control strategy is unknown.,The effectiveness depends on two key unknowns: how quickly transmission risk decreases with distance from a VL case and how much asymptomatically infected individuals contribute to transmission.,To estimate these key parameters, a spatiotemporal transmission model for VL was developed and fitted to geo-located epidemiological data on 2494 individuals from a highly endemic village in Mymensingh, Bangladesh.,A Bayesian inference framework that could account for the unknown infection times of the VL cases, and missing symptom onset and recovery times, was developed to perform the parameter estimation.,The parameter estimates obtained suggest that, in a highly endemic setting, VL risk decreases relatively quickly with distance from a case-halving within 90m-and that VL cases contribute significantly more to transmission than asymptomatic individuals.,These results suggest that spatially-targeted interventions may be effective for limiting transmission.,However, the extent to which spatial transmission patterns and the asymptomatic contribution vary with VL endemicity and over time is uncertain.,In any event, interventions would need to be performed promptly and in a large radius (≥300m) around a new case to reduce transmission risk.

The history of Chagas disease control in Peru and many other nations is marked by scattered and poorly documented vector control campaigns.,The complexities of human migration and sporadic control campaigns complicate evaluation of the burden of Chagas disease and dynamics of Trypanosoma cruzi transmission.,We conducted a cross-sectional serological and entomological study to evaluate temporal and spatial patterns of T. cruzi transmission in a peri-rural region of La Joya, Peru.,We use a multivariate catalytic model and Bayesian methods to estimate incidence of infection over time and thereby elucidate the complex history of transmission in the area.,Of 1,333 study participants, 101 (7.6%; 95% CI: 6.2-9.0%) were confirmed T. cruzi seropositive.,Spatial clustering of parasitic infection was found in vector insects, but not in human cases.,Expanded catalytic models suggest that transmission was interrupted in the study area in 1996 (95% credible interval: 1991-2000), with a resultant decline in the average annual incidence of infection from 0.9% (95% credible interval: 0.6-1.3%) to 0.1% (95% credible interval: 0.005-0.3%).,Through a search of archival newspaper reports, we uncovered documentation of a 1995 vector control campaign, and thereby independently validated the model estimates.,High levels of T. cruzi transmission had been ongoing in peri-rural La Joya prior to interruption of parasite transmission through a little-documented vector control campaign in 1995.,Despite the efficacy of the 1995 control campaign, T. cruzi was rapidly reemerging in vector populations in La Joya, emphasizing the need for continuing surveillance and control at the rural-urban interface.

In West Africa, Trypanosoma brucei gambiense, causing human African trypanosomiasis (HAT), is associated with a great diversity of infection outcomes.,In addition to patients who can be diagnosed in the early hemolymphatic phase (stage 1) or meningoencephalitic phase (stage 2), a number of individuals can mount long-lasting specific serological responses while the results of microscopic investigations are negative (SERO TL+).,Evidence is now increasing to indicate that these are asymptomatic subjects with low-grade parasitemia.,The goal of our study was to investigate the type of immune response occurring in these “trypanotolerant” subjects.,Cytokines levels were measured in healthy endemic controls (n = 40), stage 1 (n = 10), early stage 2 (n = 19), and late stage 2 patients (n = 23) and in a cohort of SERO TL+ individuals (n = 60) who were followed up for two years to assess the evolution of their parasitological and serological status.,In contrast to HAT patients which T-cell responses appeared to be activated with increased levels of IL2, IL4, and IL10, SERO TL+ exhibited high levels of proinflammatory cytokines (IL6, IL8 and TNFα) and an almost absence of IL12p70.,In SERO TL+, high levels of IL10 and low levels of TNFα were associated with an increased risk of developing HAT whereas high levels of IL8 predicted that serology would become negative.,Further studies using high throughput technologies, hopefully will provide a more detailed view of the critical molecules or pathways underlying the trypanotolerant phenotype.

Haptoglobin, coded by the HP gene, is a plasma protein that acts as a scavenger for free heme, and haptoglobin-related protein (coded by the HPR gene) forms part of the trypanolytic factor TLF-1, together with apolipoprotein L1 (ApoL1).,We analyse the polymorphic small intragenic duplication of the HP gene, with alleles Hp1 and Hp2, in 52 populations, and find no evidence for natural selection either from extended haplotype analysis or from correlation with pathogen richness matrices.,Using fiber-FISH, the paralog ratio test, and array-CGH data, we also confirm that the HPR gene is copy number variable, with duplication of the whole HPR gene at polymorphic frequencies in west and central Africa, up to an allele frequency of 15 %.,The geographical distribution of the HPR duplication allele overlaps the region where the pathogen causing chronic human African trypanosomiasis, Trypanosoma brucei gambiense, is endemic.,The HPR duplication has occurred on one SNP haplotype, but there is no strong evidence of extended homozygosity, a characteristic of recent natural selection.,The HPR duplication shows a slight, non-significant undertransmission to human African trypanosomiasis-affected children of unaffected parents in the Democratic Republic of Congo.,However, taken together with alleles of APOL1, there is an overall significant undertransmission of putative protective alleles to human African trypanosomiasis-affected children.,The online version of this article (doi:10.1007/s00439-013-1352-x) contains supplementary material, which is available to authorized users.

Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) have been described as two distinct species, only distinguishable by molecular methods such as PCR.,Because of no well-defined endemic area and a variable clinical presentation as higher thrombocytopenia and nausea associated with Pow infection and asymptomatic forms of the pathology with Poc infection, rapid and specific identification of Plasmodium ovale curtisi and Plasmodium ovale wallikeri are needed.,The aim of the study was to evaluate a new quantitative real-time PCR coupled with high resolution melting revelation (qPCR-HRM) for identification of both species.,Results were compared with a nested-PCR, considered as a gold standard for Pow and Poc distinction. 356 samples including all human Plasmodium species at various parasitaemia were tested.,The qPCR-HRM assay allowed Poc and Pow discrimination in 66 samples tested with a limit of detection evaluated at 1 parasite/µL.,All these results were concordant with nested-PCR.,Cross-reaction was absent with others blood parasites.,The qPCR-HRM is a rapid and convenient technique to Poc and Pow distinction.

Since 1960, a total of seven species of monkey malaria have been reported as transmissible to man by mosquito bite: Plasmodium cynomolgi, Plasmodium brasilianum, Plasmodium eylesi, Plasmodium knowlesi, Plasmodium inui, Plasmodium schwetzi and Plasmodium simium.,With the exception of P. knowlesi, none of the other species has been found to infect humans in nature.,In this report, it is described the first known case of a naturally acquired P. cynomolgi malaria in humans.,The patient was a 39-year-old woman from a malaria-free area with no previous history of malaria or travel to endemic areas.,Initially, malaria was diagnosed and identified as Plasmodium malariae/P. knowlesi by microscopy in the Terengganu State Health Department.,Thick and thin blood films stained with 10% Giemsa were performed for microscopy examination.,Molecular species identification was performed at the Institute for Medical Research (IMR, Malaysia) and in the Malaria & Emerging Parasitic Diseases Laboratory (MAPELAB, Spain) using different nested PCR methods.,Microscopic re-examination in the IMR showed characteristics of Plasmodium vivax and was confirmed by a nested PCR assay developed by Snounou et al.,Instead, a different PCR assay plus sequencing performed at the MAPELAB confirmed that the patient was infected with P. cynomolgi and not with P. vivax.,This is the first report of human P. cynomolgi infection acquired in a natural way, but there might be more undiagnosed or misdiagnosed cases, since P. cynomolgi is morphologically indistinguishable from P. vivax, and one of the most used PCR methods for malaria infection detection may identify a P. cynomolgi infection as P. vivax.,Simian Plasmodium species may routinely infect humans in Southeast Asia.,New diagnostic methods are necessary to distinguish between the human and monkey malaria species.,Further epidemiological studies, incriminating also the mosquito vector(s), must be performed to know the relevance of cynomolgi malaria and its implication on human public health and in the control of human malaria.,The zoonotic malaria cannot be ignored in view of increasing interactions between man and wild animals in the process of urbanization.

It has been proposed that helminth infection may be particularly detrimental during pregnancy, through adverse effects on maternal anaemia and on birth outcomes, and that anthelminthic treatment during pregnancy will therefore be particularly beneficial.,However, the few treatment trials that have been conducted have given, but little support to this notion and further trials in settings of nutritional stress are needed.,It has also been proposed that prenatal exposure to helminth infection has an important effect on the development of the foetal immune response.,There is evidence that this may impact, long-term, upon responses to helminth and nonhelminth antigens, and to allergens.,Exposure to helminths in utero may also have nonspecific effects that may modify the offspring's susceptibility to diseases mediated by inflammation, including metabolic disorders.,The mechanisms of such effects are not known, but they deserve to be explored as current epidemiological findings suggest the possibility of primary prevention for inflammatory conditions such as allergy, through intervention during pregnancy.

Malaria and hookworm infections are common in sub-Saharan Africa and they increase the prevalence of anaemia in pregnancy with resultant poor pregnancy outcomes.,This study was carried out to assess the impact of Plasmodium falciparum and hookworm infections on the frequency of anaemia among pregnant women in two rural communities in Enugu, South East Nigeria.,A cross sectional descriptive study was carried out in a total of 226 women attending antenatal clinics at two rural Primary Health Centres (PHC) from April 2011 to July 2011(each PHC with 113 subjects).,Socio-demographic data were collected through a structured questionnaire.,Blood and stool samples were evaluated for haemoglobin estimation and malaria parasites, and stool samples examined for parasitic infection in all the women.,Data was analyzed using STATA 10 software statistical analysis package.,Student t-test was used for comparing mean values and chi square test for comparing categorical variables and level of significance set at p<0.05 and logistic regression was used to identify the risk factors associated with malaria in pregnancy.,The mean age of the women was 27years with range 18 - 38years and SD of 5years.,Most of the women were housewives and over 50% in their second trimester. 53% of them had malaria parasites while 27% had hookworm infection.,About 40% of the women were anaemic (haemoglobin < 0.001).,Similar association was found between hookworm infection and anaemia (p <0.001).,Though both malaria and hookworm infections greatly increase the odds for anaemia (AOR 18.06, CI 18.15 -39.99, P<0.001) and (AOR 5.28, CI 2.26-12.38, P<0.001) respectively, the odds for having anaemia in pregnancy was higher for malaria than hookworm infections.,Plasmodium falciparum and hookworm infections have significant impact on the high frequency of anaemia in pregnancy in our rural communities.,There is need to strengthen the control program that has been in place with an integrated intervention to combat these parasitic infections in our rural communities, with mass distribution of antihelminthics as one of the included relevant methods, among others.

The epidemiology of malaria in “low-transmission” areas has been underestimated.,Molecular detection methods have revealed higher prevalences of malaria than conventional microscopy or rapid diagnostic tests, but these typically evaluate finger-prick capillary blood samples (∼5 μl) and therefore cannot detect parasite densities of <200/ml.,Their use underestimates true parasite carriage rates.,To characterize the epidemiology of malaria in low-transmission settings and plan elimination strategies, more sensitive quantitative PCR (qPCR) is needed to identify and quantify low-density malaria parasitemias.,A highly sensitive “high-volume” quantitative PCR (qPCR) method based on Plasmodium sp.,18S RNA was adapted for blood sample volumes of ≥250 μl and scaled for high throughput.,The methods were validated by assessment of the analytical sensitivity and specificity, diagnostic sensitivity, and specificity, efficiency, precision, analytical and diagnostic accuracies, limit of detection, root cause analysis of false positives, and robustness.,The high-volume qPCR method based on Plasmodium sp.,18S RNA gave high PCR efficiency of 90 to 105%.,Concentrations of parasite DNA from large volumes of blood gave a consistent analytical detection limit (LOD) of 22 parasites/ml (95% CI, 21.79 to 74.9), which is some 2,500 times more sensitive than conventional microscopy and 50 times more sensitive than currently used PCR methods from filter paper blood spots.,The diagnostic specificity was 99.75%.,Using automated procedures it was possible to process 700 blood samples per week.,A very sensitive and specific high-throughput high-volume qPCR method for the detection of low-density parasitemias (>20 parasites/ml) was developed and validated.

The marginal costs and benefits of converting malaria programmes from a control to an elimination goal are central to strategic decisions, but empirical evidence is scarce.,We present a conceptual framework to assess the economics of elimination and analyse a central component of that framework-potential short-term to medium-term financial savings.,After a review that showed a dearth of existing evidence, the net present value of elimination in five sites was calculated and compared with effective control.,The probability that elimination would be cost-saving over 50 years ranged from 0% to 42%, with only one site achieving cost-savings in the base case.,These findings show that financial savings should not be a primary rationale for elimination, but that elimination might still be a worthy investment if total benefits are sufficient to outweigh marginal costs.,Robust research into these elimination benefits is urgently needed.

•Sexual reproduction is obligate for malaria parasite transmission.,•Parasites have evolved “strategies” to maximise the success of sexual reproduction.,•Evolutionary and ecological theories can explain parasite reproductive strategies.,•Parasite strategies could undermine transmission-blocking interventions.,•Targeting parasite strategies offers novel opportunities for interventions.,Sexual reproduction is obligate for malaria parasite transmission.,Parasites have evolved “strategies” to maximise the success of sexual reproduction.,Evolutionary and ecological theories can explain parasite reproductive strategies.,Parasite strategies could undermine transmission-blocking interventions.,Targeting parasite strategies offers novel opportunities for interventions.,Malaria parasites exhibit a complex lifecycle, requiring extensive asexual replication in the liver and blood of the vertebrate host, and in the haemocoel of the insect vector.,Yet, they must also undergo a single round of sexual reproduction, which occurs in the vector’s midgut upon uptake of a blood meal.,Sexual reproduction is obligate for infection of the vector and thus, is essential for onwards transmission to new hosts.,Sex in malaria parasites involves several bottlenecks in parasite number, making the stages involved attractive targets for blocking disease transmission.,Malaria parasites have evolved a suite of adaptations (“strategies”) to maximise the success of sexual reproduction and transmission, which could undermine transmission-blocking interventions.,Yet, understanding parasite strategies may also reveal novel opportunities for such interventions.,Here, we outline how evolutionary and ecological theories, developed to explain reproductive strategies in multicellular taxa, can be applied to explain two reproductive strategies (conversion rate and sex ratio) expressed by malaria parasites within the vertebrate host.

Immunization with attenuated Plasmodium falciparum sporozoites (PfSPZ) has been shown to be protective, but the features of the antibody response induced by this treatment remain unclear.,To investigate this response at high resolution, we isolated IgM and IgG monoclonal antibodies from Tanzanian volunteers who were immunized by repeated injection of irradiated PfSPZ and who were found to be protected from controlled human malaria infection (CHMI) with infectious homologous PfSPZ.,All IgG monoclonals isolated bound to P. falciparum circumsporozoite protein (PfCSP) and recognized distinct epitopes in the N-terminus, NANP repeat region, and C-terminus.,Strikingly, the most effective antibodies, as assessed in a humanized mouse model, bound not only to the repeat region, but also to a minimal peptide at the PfCSP N-terminal junction that is not in the RTS,S vaccine.,These dual-specific antibodies were isolated from different donors and used VH3-30 or VH3-33 alleles carrying tryptophan or arginine at position 52.,Using structural and mutational data, we describe the elements required for germline recognition and affinity maturation.,Our study provides potent neutralizing antibodies and relevant information for lineage-targeted vaccine design and immunization strategies.

A novel ultrasensitive malaria rapid diagnostic test (us-RDT) has been developed for improved active Plasmodium falciparum infection detection.,The usefulness of this us-RDT in clinical diagnosis and fever management has not been evaluated.,Diagnostic performance of us-RDT was compared retrospectively to that of conventional RDT (co-RDT) in 3000 children and 515 adults presenting with fever to Tanzanian outpatient clinics.,The parasite density was measured by an ultrasensitive qPCR (us-qPCR), and the HRP2 concentration was measured by an enzyme-linked immunosorbent assay.,us-RDT identified few additional P. falciparum-positive patients as compared to co-RDT (276 vs 265 parasite-positive patients detected), with only a marginally greater sensitivity (75% vs 73%), using us-qPCR as the gold standard (357 parasite-positive patients detected).,The specificity of both RDTs was >99%.,Five of 11 additional patients testing positive by us-RDT had negative results by us-qPCR.,The HRP2 concentration was above the limit of detection for co-RDT (>3653 pg of HRP2 per mL of blood) in almost all infections (99% [236 of 239]) with a parasite density >100 parasites per µL of blood.,At parasite densities <100 parasites/µL, the HRP2 concentration was above the limits of detection of us-RDT (>793 pg/mL) and co-RDT in 29 (25%) and 24 (20%) of 118 patients, respectively.,There is neither an advantage nor a risk of using us-RDT, rather than co-RDT, for clinical malaria diagnosis.,In febrile patients, only a small proportion of infections are characterized by a parasite density or an HRP2 concentration in the range where use of us-RDT would confer a meaningful advantage over co-RDT.,Ultrasensitive rapid diagnostic tests (RDTs) for malaria, designed for Plasmodium falciparum elimination campaigns, may be used off label in clinical practice.,The diagnostic performances of ultrasensitive and conventional RDTs were similar in febrile Tanzanian outpatients, which is explained by the underlying HRP2 concentration and parasite density distributions.

Deletions of the Plasmodium falciparum hrp2 and hrp3 genes can affect the performance of HRP2-based malaria rapid diagnostic tests (RDTs).,Such deletions have been reported from South America, India and Eritrea.,Whether these parasites are widespread in East Africa is unknown.,A total of 274 samples from asymptomatic children in Mbita, western Kenya, and 61 genomic data from Kilifi, eastern Kenya, were available for analysis.,PCR-confirmed samples were investigated for the presence of pfhrp2 and pfhrp3 genes.,In samples with evidence of deletion, parasite presence was confirmed by amplifying three independent genes.,We failed to amplify pfhrp2 from 25 of 131 (19.1%) PCR-confirmed samples.,Of these, only 8 (10%) samples were microscopic positive and were classified as pfhrp2-deleted.,Eight microscopically-confirmed pfhrp2-deleted samples with intact pfhrp3 locus were positive by HRP2-based RDT.,In addition, one PCR-confirmed infection showed a deletion at the pfhrp3 locus.,One genomic sample lacked pfhrp2 and one lacked pfhrp3.,No sample harbored parasites lacking both genes.,Parasites lacking pfhrp2 are present in Kenya, but may be detectable by HRP-based RDT at higher parasitaemia, possibly due to the presence of intact pfhrp3.,These findings warrant further systematic study to establish prevalence and diagnostic significance.

Intestinal parasite infections are major public health problems in resource-limited countries that adversely affect the well-being of millions.,Among these, intestinal schistosomiasis is a serious public health problem in tropical and sub-tropical countries.,A Community based cross sectional study was conducted from February to April 2017 in Addiremets town, Ethiopia.,Socio-demographic associated risk factors and knowledge, attitude and practices of individuals regarding intestinal parasite infection including schistosomiasis were collected from 411 study participants using pretested structured questionnaires.,From each study participant, a fresh stool sample was collected and direct microscopy, formol-ether concentration and Kato- Katz techniques were performed.,Snails were checked and collected from the nearby study area river.,The collected data was entered and analyzed using SPSS version 20.,Bi-variant and multiple logistic regressions were used for correlation analysis.,A P <0.05 was considered as statistically significant.,The overall intestinal parasite prevalence was 51.3% (211/411).,The most prevalent parasites were S. mansoni 26.3%(108/411) and Hookworm 23.1%(95/411).,The prevalence of intestinal parasites among males and females were 54.1%(131/242) and 47.3%(80/169) respectively.,The highest proportion of parasite infection was reported among the age group of 5-9 year old participants, at 70.6%(36/51).,The prevalence of S. mansoni was 26.3% (108/411) with mean infection intensity of 218 eggs per gram (range: 24 to 1728).,Among study participants, 94.4% had good knowledge while 35.9% of them had poor practices towards intestinal parasite and Schistosomes infection prevention.,High prevalence of intestinal parasitic infection was observed in Addiremets town and the most common parasites identified were S. mansoni and Hookworm.,Most study participants had light infection intensity of Schistosomiasis, Ascariasis and Hookworm infection.,Majority of the participants in the study area had good knowledge and positive attitude about intestinal parasitic infection and schistosomiasis control.,Shells of Biomphalaria species, Bulinus species and Physa species were collected from the Mytsaeda river shore.

In South Africa, studies on the prevalence of intestinal helminth co-infection amongst HIV-infected patients as well as possible interactions between these two infections are limited.,To investigate the prevalence of intestinal helminth infestation amongst adults living with HIV or AIDS at Mthatha General Hospital.,Study participants were recruited at the outpatient department of Mthatha General Hospital, Mthatha, South Africa.,This cross-sectional study was conducted between October and December 2013 amongst consecutive consenting HIV-positive adult patients.,Socio-demographic and clinical information were obtained using data collection forms and structured interviews.,Stool samples were collected to investigate the presence of helminths whilst blood samples were obtained for the measurement of CD4+ T-cell count and viral load.,Data were obtained on 231 participants, with a mean age of 34.9 years, a mean CD4 count of 348 cells/µL and a mean viral load of 4.8 log10 copies/mL.,Intestinal helminth prevalence was 24.7%, with Ascaris Lumbricoides (42.1%) the most prevalent identified species.,Statistically significant association was found between CD4 count of less than 200 cells/µL and helminth infection (p = 0.05).,No statistically significant association was found between intestinal helminth infection and the mean CD4 count (p = 0.79) or the mean viral load (p = 0.98).,A high prevalence of intestinal helminth infections was observed amongst the study population.,Therefore, screening and treatment of helminths should be considered as part of the management of HIV and AIDS in primary health care.

•Report of a Phase I clinical trial to assess a malaria transmission blocking vaccine.,•P. falciparum Pfs25 virus-like particle produced under cGMP in a plant-based system.,•The vaccine candidate displays an acceptable safety and tolerability profile.,•The vaccine candidate induced Pfs25-specific IgG in a dose dependent manner.,•However, low transmission reducing activity implies need for an improved formulation.,Report of a Phase I clinical trial to assess a malaria transmission blocking vaccine.,P. falciparum Pfs25 virus-like particle produced under cGMP in a plant-based system.,The vaccine candidate displays an acceptable safety and tolerability profile.,The vaccine candidate induced Pfs25-specific IgG in a dose dependent manner.,However, low transmission reducing activity implies need for an improved formulation.,Malaria continues to be one of the world’s most devastating infectious tropical diseases, and alternative strategies to prevent infection and disease spread are urgently needed.,These strategies include the development of effective vaccines, such as malaria transmission blocking vaccines (TBV) directed against proteins found on the sexual stages of Plasmodium falciparum parasites present in the mosquito midgut.,The Pfs25 protein, which is expressed on the surface of gametes, zygotes and ookinetes, has been a primary target for TBV development.,One such vaccine strategy based on Pfs25 is a plant-produced malaria vaccine candidate engineered as a chimeric non-enveloped virus-like particle (VLP) comprising Pfs25 fused to the Alfalfa mosaic virus coat protein.,This Pfs25 VLP-FhCMB vaccine candidate has been engineered and manufactured in Nicotiana benthamiana plants at pilot plant scale under current Good Manufacturing Practice guidelines.,The safety, reactogenicity and immunogenicity of Pfs25 VLP-FhCMB was assessed in healthy adult volunteers.,This Phase 1, dose escalation, first-in-human study was designed primarily to evaluate the safety of the purified plant-derived Pfs25 VLP combined with Alhydrogel® adjuvant.,At the doses tested in this Phase 1 study, the vaccine was generally shown to be safe in healthy volunteers, with no incidence of vaccine-related serious adverse events and no evidence of any dose-limiting or dose-related toxicity, demonstrating that the plant-derived Pfs25 VLP-FhCMB vaccine had an acceptable safety and tolerability profile.,In addition, although the vaccine did induce Pfs25-specific IgG in vaccinated patients in a dose dependent manner, the transmission reducing activity of the antibodies generated were weak, suggesting the need for an alternative vaccine adjuvant formulation.,This study was registered at www.ClinicalTrials.gov under reference identifier NCT02013687.

Immunization with attenuated Plasmodium falciparum sporozoites (PfSPZ) has been shown to be protective, but the features of the antibody response induced by this treatment remain unclear.,To investigate this response at high resolution, we isolated IgM and IgG monoclonal antibodies from Tanzanian volunteers who were immunized by repeated injection of irradiated PfSPZ and who were found to be protected from controlled human malaria infection (CHMI) with infectious homologous PfSPZ.,All IgG monoclonals isolated bound to P. falciparum circumsporozoite protein (PfCSP) and recognized distinct epitopes in the N-terminus, NANP repeat region, and C-terminus.,Strikingly, the most effective antibodies, as assessed in a humanized mouse model, bound not only to the repeat region, but also to a minimal peptide at the PfCSP N-terminal junction that is not in the RTS,S vaccine.,These dual-specific antibodies were isolated from different donors and used VH3-30 or VH3-33 alleles carrying tryptophan or arginine at position 52.,Using structural and mutational data, we describe the elements required for germline recognition and affinity maturation.,Our study provides potent neutralizing antibodies and relevant information for lineage-targeted vaccine design and immunization strategies.

The current epidemic of artemisinin resistant Plasmodium falciparum in Southeast Asia is the result of a soft selective sweep involving at least 20 independent kelch13 mutations.,In a large global survey, we find that kelch13 mutations which cause resistance in Southeast Asia are present at low frequency in Africa.,We show that African kelch13 mutations have originated locally, and that kelch13 shows a normal variation pattern relative to other genes in Africa, whereas in Southeast Asia there is a great excess of non-synonymous mutations, many of which cause radical amino-acid changes.,Thus, kelch13 is not currently undergoing strong selection in Africa, despite a deep reservoir of variations that could potentially allow resistance to emerge rapidly.,The practical implications are that public health surveillance for artemisinin resistance should not rely on kelch13 data alone, and interventions to prevent resistance must account for local evolutionary conditions, shown by genomic epidemiology to differ greatly between geographical regions.,DOI:http://dx.doi.org/10.7554/eLife.08714.001,Malaria is an infectious disease caused by a microscopic parasite called Plasmodium, which is transferred between humans by mosquitos.,One species of malaria parasite called Plasmodium falciparum can cause particularly severe and life-threatening forms of the disease.,Currently, the most widely used treatment for P. falciparum infections is artemisinin combination therapy, a treatment that combines the drug artemisinin (or a closely related molecule) with another antimalarial drug.,However, resistance to artemisinin has started to spread throughout Southeast Asia.,Artemisinin resistance is caused by mutations in a parasite gene called kelch13, and researchers have identified over 20 different mutations in P. falciparum that confer artemisinin resistance.,The diversity of mutations involved, and the fact that the same mutation can arise independently in different locations, make it difficult to track the spread of resistance using conventional molecular marker approaches.,Here, Amato, Miotto et al. sequenced the entire genomes of more than 3,000 clinical samples of P. falciparum from Southeast Asia and Africa, collected as part of a global network of research groups called the MalariaGEN Plasmodium falciparum Community Project.,Amato, Miotto et al. found that African parasites had independently acquired many of the same kelch13 mutations that are known to cause resistance to artemisinin in Southeast Asia.,However the kelch13 mutations seen in Africa remained at low levels in the parasite population, and appeared to be under much less pressure for evolutionary selection than those found in Southeast Asia.,These findings demonstrate that the emergence and spread of resistance to antimalarial drugs does not depend solely on the mutational process, but also on other factors that influence whether the mutations will spread in the population.,Understanding how this is affected by different patterns of drug treatments and other environmental conditions will be important in developing more effective strategies for combating malaria.,DOI:http://dx.doi.org/10.7554/eLife.08714.002

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.

Plasmodium vivax is the most widespread human malaria, putting 2.5 billion people at risk of infection.,Its unique biological and epidemiological characteristics pose challenges to control strategies that have been principally targeted against Plasmodium falciparum.,Unlike P. falciparum, P. vivax infections have typically low blood-stage parasitemia with gametocytes emerging before illness manifests, and dormant liver stages causing relapses.,These traits affect both its geographic distribution and transmission patterns.,Asymptomatic infections, high-risk groups, and resulting case burdens are described in this review.,Despite relatively low prevalence measurements and parasitemia levels, along with high proportions of asymptomatic cases, this parasite is not benign.,Plasmodium vivax can be associated with severe and even fatal illness.,Spreading resistance to chloroquine against the acute attack, and the operational inadequacy of primaquine against the multiple attacks of relapse, exacerbates the risk of poor outcomes among the tens of millions suffering from infection each year.,Without strategies accounting for these P. vivax-specific characteristics, progress toward elimination of endemic malaria transmission will be substantially impeded.

An estimated 2.85 billion people live at risk of Plasmodium vivax transmission.,In endemic countries vivax malaria causes significant morbidity and its mortality is becoming more widely appreciated, drug-resistant strains are increasing in prevalence, and an increasing number of reports indicate that P. vivax is capable of breaking through the Duffy-negative barrier long considered to confer resistance to blood stage infection.,Absence of robust in vitro propagation limits our understanding of fundamental aspects of the parasite's biology, including the determinants of its dormant hypnozoite phase, its virulence and drug susceptibility, and the molecular mechanisms underlying red blood cell invasion.,Here, we report results from whole genome sequencing of five P. vivax isolates obtained from Malagasy and Cambodian patients, and of the monkey-adapted Belem strain.,We obtained an average 70-400 X coverage of each genome, resulting in more than 93% of the Sal I reference sequence covered by 20 reads or more.,Our study identifies more than 80,000 SNPs distributed throughout the genome which will allow designing association studies and population surveys.,Analysis of the genome-wide genetic diversity in P. vivax also reveals considerable allele sharing among isolates from different continents.,This observation could be consistent with a high level of gene flow among parasite strains distributed throughout the world.,Our study shows that it is feasible to perform whole genome sequencing of P. vivax field isolates and rigorously characterize the genetic diversity of this parasite.,The catalogue of polymorphisms generated here will enable large-scale genotyping studies and contribute to a better understanding of P. vivax traits such as drug resistance or erythrocyte invasion, partially circumventing the lack of laboratory culture that has hampered vivax research for years.

We examined the mitogenomes of a large global collection of human malaria parasites to explore how and when Plasmodium falciparum and P. vivax entered the Americas.,We found evidence of a significant contribution of African and South Asian lineages to present-day New World malaria parasites with additional P. vivax lineages appearing to originate from Melanesia that were putatively carried by the Australasian peoples who contributed genes to Native Americans.,Importantly, mitochondrial lineages of the P. vivax-like species P. simium are shared by platyrrhine monkeys and humans in the Atlantic Forest ecosystem, but not across the Amazon, which most likely resulted from one or a few recent human-to-monkey transfers.,While enslaved Africans were likely the main carriers of P. falciparum mitochondrial lineages into the Americas after the conquest, additional parasites carried by Australasian peoples in pre-Columbian times may have contributed to the extensive diversity of extant local populations of P. vivax.

There is large body of evidence that states that invasion of Plasmodium vivax requires the Duffy antigen, but the universality of this specificity is certainly now under question with recent reports showing that in some parts of the world P. vivax infects and causes disease in Duffy-negative people.,These findings reinforce the idea that this parasite is rapidly evolving, being able to use other receptors than Duffy to invade the erythrocytes, which may have an enormous impact in P. vivax current distribution.,The presence of P. vivax infection in Duffy-negative individuals was investigated in a cross-sectional study conducted in Anajás, Archipelago of Marajó, State of Pará, which is an area of malaria transmission in the Brazilian Amazonia.,Duffy genotyping and Plasmodium species diagnostic assays were performed successfully in 678 individuals.,An allele-specific primer polymerase chain reaction (PCR) technique was used for Duffy blood group genotyping.,Identification of Plasmodium species was achieved by conventional blood smear light microscopy and a TaqMan-based real-time PCR method to detect mitochondrial genome of Plasmodium falciparum and P. vivax.,Plasmodium spp. infection was detected in 137 samples (20.2%).,Prevalence of each Plasmodium species was 13.9% P. vivax, 5.8% P. falciparum, and 0.6% P. vivax plus P. falciparum.,Overall, 4.3% (29/678) were genotyped as Duffy-negative (FY*BES/*BES).,Among Duffy-negative individuals 6.9% were P. vivax PCR positive and among Duffy-positive 14.2% were P. vivax PCR positive.,Although lower, the risk of Duffy-negatives to experience a P. vivax blood stage infection was not significantly different to that of Duffy-positives.,Furthermore, the genotypic and allelic frequencies of the Duffy blood group among P. vivax-infected patients and in the control group did not differ significantly, also suggesting no reduction in infection rates among the carriers of FY*BES allele.,The data obtained in Anajás showed no differential resistance vivax malaria among Duffy-negative and Duffy-positive individuals.,This result needs additional confirmation through a deeper evaluation in a larger sample of patients with P. vivax malaria and molecular parasite characterization.,Nonetheless, this genetic profile of the parasite may be contributing to the high incidence of malaria in the municipality.

Malaria remains a major public health problem in Madagascar.,Widespread scale-up of intervention coverage has led to substantial reductions in case numbers since 2000.,However, political instability since 2009 has disrupted these efforts, and a resurgence of malaria has since followed.,This paper re-visits the sub-national stratification of malaria transmission across Madagascar to propose a contemporary update, and evaluates the reported routine case data reported at this sub-national scale.,Two independent malariometrics were evaluated to re-examine the status of malaria across Madagascar.,First, modelled maps of Plasmodium falciparum infection prevalence (PfPR) from the Malaria Atlas Project were used to update the sub-national stratification into ‘ecozones’ based on transmission intensity.,Second, routine reports of case data from health facilities were synthesized from 2010 to 2015 to compare the sub-national epidemiology across the updated ecozones over time.,Proxy indicators of data completeness are investigated.,The epidemiology of malaria is highly diverse across the island’s ecological regions, with eight contiguous ecozones emerging from the transmission intensity PfPR map.,East and west coastal areas have highest transmission year-round, contrasting with the central highlands and desert south where trends appear more closely associated with epidemic outbreak events.,Ecozones have shown steady increases in reported malaria cases since 2010, with a near doubling of raw reported case numbers from 2014 to 2015.,Gauges of data completeness suggest that interpretation of raw reported case numbers will underestimate true caseload as only approximately 60-75 % of health facility data are reported to the central level each month.,A sub-national perspective is essential when monitoring the epidemiology of malaria in Madagascar and assessing local control needs.,A robust assessment of the status of malaria at a time when intervention coverage efforts are being scaled up provides a platform from which to guide intervention preparedness and assess change in future periods of transmission.,The online version of this article (doi:10.1186/s12936-016-1556-3) contains supplementary material, which is available to authorized users.

In Madagascar, indoor residual spraying (IRS) with insecticide was part of the national malaria control programme since the middle of the twentieth century.,It was mainly employed in the highlands and the foothill areas, which are prone to malaria epidemics.,Prior to a policy change foreseeing a shift from DDT to pyrethroids, a study was carried out to assess the entomological and parasitological impacts of IRS in areas with DDT or pyrethroids and in areas without IRS.,The study was carried out from October 2002 to February 2005 in three communes of the western foothill area of Madagascar.,Two communes received IRS with DDT in February 2003, then IRS with pyrethroids (alphacypermethrin or deltamethrin) in February 2004.,The third commune remained untreated.,Mosquitoes were collected at night using human landing catches and early in the morning in resting places.,Blood smears were obtained from schoolchildren and microscopically examined for Plasmodium presence.,In total, 18,168 human landing mosquitoes and 12,932 resting anophelines were collected.,The Anopheles species caught comprised 10 species.,The main and most abundant malaria vector was Anopheles funestus (72.3% of human-seeking malaria vectors caught indoors).,After IRS had taken place, this species exhibited a lower human biting rate and a lower sporozoite index.,Overall, 5,174 blood smears were examined with a mean plasmodic index of 19.9%.,A total of four Plasmodium species were detected.,Amongst tested school children the highest plasmodial index was 54.6% in the untreated commune, compared to 19.9% in the commune sprayed with DDT and 11.9% in the commune sprayed with pyrethroid.,The highest prevalence of clinical malaria attacks in children present at school the day of the survey was 33% in the untreated commune compared to 8% in the areas which received IRS.,In terms of public health, the present study shows (1) a high efficacy of IRS with insecticide, (2) a similar efficacy of DDT and pyrethroid and (3) a similar efficacy of alphacypermethrin and deltamethrin.,The use of IRS with DDT and pyrethroid greatly decreased the vector-human contact, with an associated decrease of the plasmodial index.,However malaria transmission did not reach zero, probably due to the exophilic host-seeking and resting behaviours of the malaria vectors, thus avoiding contact with insecticide-treated surfaces indoors.,The study highlights the strengths and weaknesses of the IRS implementation and the need for complementary tools for an optimal vector control in Madagascar.

The epidemiology of feline vector-borne pathogens (FeVBPs) has been less investigated in cats than in dogs.,The present study assessed the prevalence of Rickettsia spp., Babesia spp., Cytauxzoon spp. and Leishmania infantum infections in cat populations living in central Italy, by molecular and serological tools.,A total of 286 healthy cats were randomly selected from catteries and colonies in central Italy.,Peripheral blood and conjunctival swab (CS) samples were collected during surgical procedures for regional neutering projects.,Sera were analysed by IFAT to detect anti-Rickettsia felis, R. conorii, Babesia microti and Leishmania IgG antibodies using commercial and home-made antigens.,DNA extracted from buffy coats (BCs) was tested for Rickettsia spp., and Piroplasmida species, including Cytauxzoon spp. and Babesia spp. by PCR.,Buffy coats and CS samples were assayed by a nested (n)-PCR for Leishmania spp.,Sixty-two cats (21.67%) were seropositive to at least one of the tested pathogens.,The serological assay revealed 23 (8.04%) and 18 (6.29%) positive cats for R. felis and R. conorii, respectively, with low titers (1/64-1/128).,No antibodies against B. microti were detected.,Neither Rickettsia nor Piroplasmida DNA were amplified using the specific PCR assays.,Thirty-one cats (10.83%) tested positive to anti-Leishmania IgG, with titers ranging from 1:40 to 1:160 and 45 animals (15.73%) tested positive to Leishmania CS n-PCR, whereas none of the animals tested positive to BC n-PCR.,Considering the results obtained by IFAT and CS n-PCR, a moderate agreement between the two tests was detected (κ = 0.27).,The results of the serological and molecular surveys showed a moderate exposure to Leishmania in the investigated cats and highlighted the limited molecular diagnostic value of BC versus CS samples for this pathogen.,Conversely no evidence supported the circulation of Cytauxzoon spp. in domestic cats, in contrast with previous detections in European wild cats in the same areas monitored.,The low positive titres for R. felis in association with no DNA BC amplification prevent speculation on the exposure of feline populations to this FeVBP due to the cross-reactivity existing within spotted fever group rickettsiosis (SFGR).

While in Europe Babesia canis has been traditionally held responsible for canine piroplasmosis, Babesia microti-like piroplasm (Bml) infection is being ever more observed in dogs, with the first clinical cases reported in northwestern Spain.,This study examines the epidemiological role of healthy dogs living in endemic areas of Bml infection in Spain.,The data obtained were used to describe the clinical status and map the geographical distribution of Bml infection in healthy dogs in northwestern Spain.,Blood samples and ticks were taken from 756 healthy dogs representatively across the whole Galicia region (northwestern Spain): stray (n = 211), hunting dogs (n = 333) and pets (n = 212).,Blood samples were tested by microscopy parasite observation, nested PCR-RFLP and sequencing.,Piroplasm infection prevalences in healthy dogs from northwestern Spain were 17.1% (129/756) by PCR and 3.4% (26/756) by microscopy observation.,The species found by PCR were: 2.2% (17/756) for B. canis and 15.1% (114/756) for Bml.,Co-infection with B. canis and Bml was noted in 2 dogs.,The higher prevalences detected were Bml in hunting dogs (25.5%; 85/333) and B. canis in stray dogs (6.6%; 14/211).,In fox-hunting dogs from any area and dogs from the A Coruña Province, significantly higher prevalences of Bml infection were detected (P < 0.001).,Upon physical examination, tick infestation was observed: 130 ticks in 18 hunting and three pet dogs.,These were subsequently identified as Rhipicephalus sanguineus (s.l.),(49.2%), Ixodes hexagonus (38.5%), Ixodes ricinus (6.9%) and Dermacentor reticulatus (5.4%).,Among the more prevalent ticks infesting healthy carrier dogs were I. hexagonus, followed by D. reticulatus and I. ricinus.,Babesia canis and Bml were the only piroplasm species found infecting healthy dogs in Galicia, the prevalence of Bml being higher than of B. canis.,Factors correlated with a higher Bml infection risk were being a hunting dog and living in the A Coruña Province.,Healthy dogs travelling to other countries could act as carriers and probably contribute to the spread of Bml infection in dogs and wild carnivores throughout Europe.

Several studies indicate that people of the Fulani ethnic group are less susceptible to malaria compared to those of other ethnic groups living sympatrically in Africa, including the Dogon ethnic group.,Although the mechanisms of this protection remain unclear, the Fulani are known to have higher levels of Plasmodium falciparum-specific antibodies of all Ig classes as compared to the Dogon.,However, the proportions of B cell subsets in the Fulani and Dogon that may account for differences in the levels of Ig have not been characterized.,In this cross-sectional study, venous blood was collected from asymptomatic Fulani (n = 25) and Dogon (n = 25) adults in Mali during the malaria season, and from P. falciparum-naïve adults in the U.S. (n = 8).,At the time of the blood collection, P. falciparum infection was detected by blood-smear in 16% of the Fulani and 36% of the Dogon volunteers.,Thawed lymphocytes were analysed by flow cytometry to quantify B cell subsets, including immature and naïve B cells; plasma cells; and classical, activated, and atypical memory B cells (MBCs).,The overall distribution of B cell subsets was similar between Fulani and Dogon adults, although the percentage of activated MBCs was higher in the Fulani group (Fulani: 11.07% [95% CI: 9.317 - 12.82]; Dogon: 8.31% [95% CI: 6.378 - 10.23]; P = 0.016).,The percentage of atypical MBCs was similar between Fulani and Dogon adults (Fulani: 28.3% [95% CI: 22.73 - 34.88]; Dogon: 29.3% [95% CI: 25.06 - 33.55], but higher than U.S. adults (U.S.: 3.0% [95% CI: -0.21 - 6.164]; P < 0.001).,Plasmodium falciparum infection was associated with a higher percentage of plasma cells among Fulani (Fulani infected: 3.3% [95% CI: 1.788 - 4.744]; Fulani uninfected: 1.71% [95% CI: 1.33 - 2.08]; P = 0.011), but not Dogon adults.,These data show that the malaria-resistant Fulani have a higher percentage of activated MBCs compared to the Dogon, and that P. falciparum infection is associated with a higher percentage of plasma cells in the Fulani compared to the Dogon, findings that may account for the higher levels of P. falciparum antibodies in the Fulani.

Immunity to Plasmodium falciparum (Pf) malaria is only acquired after years of repeated infections and wanes rapidly without ongoing parasite exposure.,Antibodies are central to malaria immunity, yet little is known about the B-cell biology that underlies the inefficient acquisition of Pf-specific humoral immunity.,This year-long prospective study in Mali of 185 individuals aged 2 to 25 years shows that Pf-specific memory B-cells and antibodies are acquired gradually in a stepwise fashion over years of repeated Pf exposure.,Both Pf-specific memory B cells and antibody titers increased after acute malaria and then, after six months of decreased Pf exposure, contracted to a point slightly higher than pre-infection levels.,This inefficient, stepwise expansion of both the Pf-specific memory B-cell and long-lived antibody compartments depends on Pf exposure rather than age, based on the comparator response to tetanus vaccination that was efficient and stable.,These observations lend new insights into the cellular basis of the delayed acquisition of malaria immunity.

Development of robust, sensitive, and reproducible diagnostic tests for understanding the epidemiology of neglected tropical diseases is an integral aspect of the success of worldwide control and elimination programs.,In the treatment of onchocerciasis, clinical diagnostics that can function in an elimination scenario are non-existent and desperately needed.,Due to its sensitivity and quantitative reproducibility, liquid chromatography-mass spectrometry (LC-MS) based metabolomics is a powerful approach to this problem.,Analysis of an African sample set comprised of 73 serum and plasma samples revealed a set of 14 biomarkers that showed excellent discrimination between Onchocerca volvulus-positive and negative individuals by multivariate statistical analysis.,Application of this biomarker set to an additional sample set from onchocerciasis endemic areas where long-term ivermectin treatment has been successful revealed that the biomarker set may also distinguish individuals with worms of compromised viability from those with active infection.,Machine learning extended the utility of the biomarker set from a complex multivariate analysis to a binary format applicable for adaptation to a field-based diagnostic, validating the use of complex data mining tools applied to infectious disease biomarker discovery and diagnostic development.,An LC-MS metabolomics-based diagnostic has the potential to monitor the progression of onchocerciasis in both endemic and non-endemic geographic areas, as well as provide an essential tool to multinational programs in the ongoing fight against this neglected tropical disease.,Ultimately this technology can be expanded for the diagnosis of other filarial and/or neglected tropical diseases.

Over the past decade malaria intervention coverage has been scaled up across Africa.,However, it remains unclear what overall reduction in transmission is achievable using currently available tools.,We developed an individual-based simulation model for Plasmodium falciparum transmission in an African context incorporating the three major vector species (Anopheles gambiae s.s., An. arabiensis, and An. funestus) with parameters obtained by fitting to parasite prevalence data from 34 transmission settings across Africa.,We incorporated the effect of the switch to artemisinin-combination therapy (ACT) and increasing coverage of long-lasting insecticide treated nets (LLINs) from the year 2000 onwards.,We then explored the impact on transmission of continued roll-out of LLINs, additional rounds of indoor residual spraying (IRS), mass screening and treatment (MSAT), and a future RTS,S/AS01 vaccine in six representative settings with varying transmission intensity (as summarized by the annual entomological inoculation rate, EIR: 1 setting with low, 3 with moderate, and 2 with high EIRs), vector-species combinations, and patterns of seasonality.,In all settings we considered a realistic target of 80% coverage of interventions.,In the low-transmission setting (EIR∼3 ibppy [infectious bites per person per year]), LLINs have the potential to reduce malaria transmission to low levels (<1% parasite prevalence in all age-groups) provided usage levels are high and sustained.,In two of the moderate-transmission settings (EIR∼43 and 81 ibppy), additional rounds of IRS with DDT coupled with MSAT could drive parasite prevalence below a 1% threshold.,However, in the third (EIR = 46) with An. arabiensis prevailing, these interventions are insufficient to reach this threshold.,In both high-transmission settings (EIR∼586 and 675 ibppy), either unrealistically high coverage levels (>90%) or novel tools and/or substantial social improvements will be required, although considerable reductions in prevalence can be achieved with existing tools and realistic coverage levels.,Interventions using current tools can result in major reductions in P. falciparum malaria transmission and the associated disease burden in Africa.,Reduction to the 1% parasite prevalence threshold is possible in low- to moderate-transmission settings when vectors are primarily endophilic (indoor-resting), provided a comprehensive and sustained intervention program is achieved through roll-out of interventions.,In high-transmission settings and those in which vectors are mainly exophilic (outdoor-resting), additional new tools that target exophagic (outdoor-biting), exophilic, and partly zoophagic mosquitoes will be required.,Please see later in the article for the Editors' Summary,Half the world's population is at risk of malaria, and every year nearly one million people-mainly children living in sub-Saharan Africa-die from this mosquito-borne parasitic disease.,Most malarial deaths are caused by Plasmodium falciparum, which is transmitted to people by mainly night-biting Anopheles mosquitoes.,When infected mosquitoes feed on people, they inject sporozoites, 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 the parasitic burden causes malaria's characteristic fever.,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 spraying the insides of houses (where most Anopheles species feed and rest) with insecticides (indoor residual spraying, IRS) and by sleeping under bed nets that have been treated with long-lasting insecticides (long-lasting insecticide nets, LLINs).,Mass screening and treatment (MSAT) with effective antimalarial drugs can also reduce malaria transmission.,Early attempts to eradicate malaria (reduce its global incidence to zero) in the 1950s reduced the incidence of malaria to zero in some countries (malaria elimination) and greatly reduced malarial illnesses and deaths in others (malaria control).,However, this eradication program was aborted in the 1970s in part because of emerging drug and insecticide resistance.,Recently, the advent of artemisinin-based combination therapies and new insecticides and the prospect of a malaria vaccine have renewed interest in controlling, eliminating, and ultimately eradicating malaria.,Consequently, in September 2008, the Roll Back Malaria Partnership launched the Global Malaria Action Plan, which aims to reduce malaria deaths to near zero by 2015.,But are the currently available tools for reducing malaria transmission sufficient to control and eliminate malaria in Africa, the continent where most malaria deaths occur?,In this study, the researchers use a new mathematical model of P. falciparum transmission to investigate this question.,The researchers' P. falciparum transmission model consists of “compartments” through which individuals pass as they become infected with parasites, develop immunity, become infectious to mosquitoes, and so on.,The researchers used published data about parasite prevalence (the proportion of the population infected with parasites) and about relevant aspects of mosquito, parasite, and human biology, to estimate the chances of an individual moving between compartments.,Finally, they used the model to explore the impact over 25 years of increased coverage of LLINs, IRS, and MSAT, and of a future vaccine on malaria transmission in six representative African settings.,In a low-transmission setting, 80% coverage with LLINs reduced the parasite prevalence to below 1% in all age groups.,In two moderate-transmission settings, LLIN scale-up alone failed to reach this target but the addition of IRS and MSAT drove the parasite prevalence below 1%.,However, this combination of interventions did not control malaria in a moderate-transmission setting in which a mosquito species that bites and rests outside houses contributes to malaria transmission.,Finally, in two high-transmission settings, parasite prevalence could be driven below 1% only by setting unrealistic coverage targets for existing interventions.,This new mathematical model greatly simplifies the complex dynamics of malaria transmission and includes several assumptions about which there is considerable uncertainty.,The findings of this study are not, therefore, firm predictions of the future of malaria control in specific settings.,Nevertheless, they suggest that it should be possible to make large reductions in malaria transmission and the associated disease burden in Africa over the next 25 years using currently available tools.,Specifically, in regions where transmission is low or moderate and mosquitoes mainly feed indoors, it should be possible to reduce parasite prevalence to less than 1% provided a sustained intervention program is achieved.,Importantly, however, these findings suggest that in regions where malaria transmission is high or where mosquitoes rest and bite outside houses, new approaches will be needed to control and eliminate malaria.,Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000324.,Information is available from the World Health Organization on malaria (in several languages); the 2009 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),Information is available from the Roll Back Malaria Partnership on its approach to the global control of malaria, including the Global Malaria Action Plan and a fact sheet on malaria in Africa,MedlinePlus provides links to additional information on malaria (in English and Spanish)

The discovery of T cell epitopes is essential not only for gaining knowledge about host response to infectious disease but also for the development of immune-intervention strategies.,In Chagas disease, given the size and complexity of the Trypanosoma cruzi proteome and its interaction with the host’s immune system, the fine specificity of T cells has not been extensively studied yet, and this is particularly true for the CD4+ T cell compartment.,The aim of the present work was to optimize a protocol for the generation of parasite-specific memory T cell lines, representative of their in vivo precursor populations and capable of responding to parasite antigens after long-term culture.,Accordingly, peripheral blood mononuclear cells (PBMC) from both chronic asymptomatic and cardiac patients, and from non-infected individuals, underwent different in vitro culture and stimulation conditions.,Subsequently, cells were tested for their capacity to respond against T. cruzi lysate by measuring [3H]-thymidine incorporation and interferon-γ and GM-CSF secretion.,Results allowed us to adjust initial T. cruzi lysate incubation time as well as the number of expansions with phytohemagglutinin (PHA) and irradiated allogeneic PBMC prior to specificity evaluation.,Moreover, our data demonstrated that parasite specific T cells displayed a clear and strong activation by using T. cruzi lysate pulsed, Epstein-Barr virus (EBV)-transformed human B lymphocytes (B-LCL), as autologous antigen presenting cells.,Under these culture conditions, we generated a clone from an asymptomatic patient’s memory CD4+ T cells which responded against epimastigote and trypomastigote protein lysate.,Our results describe a culture method for isolating T. cruzi specific T cell clones from patients with Chagas disease, which enable the acquisition of information on functionality and specificity of individual T cells.

Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites.,Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls.,Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells.,The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells.,Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells.,These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation.,Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas.,In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

At the local level, malaria transmission clusters in hotspots, which may be a group of households that experience higher than average exposure to infectious mosquitoes.,Active case detection often relying on rapid diagnostic tests for mass screen and treat campaigns has been proposed as a method to detect and treat individuals in hotspots.,Data from a cross-sectional survey conducted in north-western Tanzania were used to examine the spatial distribution of Plasmodium falciparum and the relationship between household exposure and parasite density.,Dried blood spots were collected from consenting individuals from four villages during a survey conducted in 2010.,These were analysed by PCR for the presence of P. falciparum, with the parasite density of positive samples being estimated by quantitative PCR.,Household exposure was estimated using the distance-weighted PCR prevalence of infection.,Parasite density simulations were used to estimate the proportion of infections that would be treated using a screen and treat approach with rapid diagnostic tests (RDT) compared to targeted mass drug administration (tMDA) and Mass Drug Administration (MDA).,Polymerase chain reaction PCR analysis revealed that of the 3,057 blood samples analysed, 1,078 were positive.,Mean distance-weighted PCR prevalence per household was 34.5%.,Parasite density was negatively associated with transmission intensity with the odds of an infection being subpatent increasing with household exposure (OR 1.09 per 1% increase in exposure).,Parasite density was also related to age, being highest in children five to ten years old and lowest in those > 40 years.,Simulations of different tMDA strategies showed that treating all individuals in households where RDT prevalence was above 20% increased the number of infections that would have been treated from 43 to 55%.,However, even with this strategy, 45% of infections remained untreated.,The negative relationship between household exposure and parasite density suggests that DNA-based detection of parasites is needed to provide adequate sensitivity in hotspots.,Targeting MDA only to households with RDT-positive individuals may allow a larger fraction of infections to be treated.,These results suggest that community-wide MDA, instead of screen and treat strategies, may be needed to successfully treat the asymptomatic, subpatent parasite reservoir and reduce transmission in similar settings.

Type I interferons (T1IFNs) are among the earliest cytokines produced during infections due to their direct regulation by innate immune signaling pathways.,Reports have suggested that T1IFNs are produced during malaria infection, but little is known about the in vivo cellular origins of T1IFNs or their role in protection.,We have found that in addition to plasmacytoid dendritic cells, splenic red pulp macrophages (RPMs) can generate significant quantities of T1IFNs in response to P. chabaudi infection in a TLR9-, MYD88-, and IRF7-dependent manner.,Furthermore, T1IFNs regulate expression of interferon-stimulated genes redundantly with Interferon-gamma (IFNG), resulting in redundancy for resistance to experimental malaria infection.,Despite their role in sensing and promoting immune responses to infection, we observe that RPMs are dispensable for control of parasitemia.,Our results reveal that RPMs are early sentinels of malaria infection, but that effector mechanisms previously attributed to RPMs are not essential for control.

The occurrence of schistosomiasis within African infants and preschool children has been much better documented in recent years, revealing an important burden of disease previously overlooked.,Despite mounting evidence showing that treatment with praziquantel is safe, beneficial, and could be delivered within ongoing public health interventions, young children still do not have satisfactory access to this drug, and a significant treatment gap exists.,Progress towards resolution of this unfortunate health inequity is highlighted, including the development of an appropriate paediatric praziquantel formulation, and present blocks are identified on securing this issue within the international health agenda.

Ficolin-2 coded by FCN2 gene is a soluble serum protein that plays an important role in innate immunity.,In this study, we analyzed five functional polymorphisms of the FCN2 gene for their possible association with cutaneous leishmaniasis.,Initially we screened 40 Syrian Arabs for the entire FCN2 gene.,We investigated the contribution of FCN2 functional variants in 226 patients with cutaneous leishmaniasis and 286 healthy controls from Syria.,Polymorphisms in the promoter regions (−986G/A, −602G/A, −4A/G) of the FCN2 gene were assessed by TaqMan real time PCR, whereas polymorphisms in exon8 (+6359C/T and +6424G/T) were assessed by DNA sequencing.,We also measured serum ficolin-2 levels in 70 control Syrian Arabs and correlated the serum concentrations to FCN2 genotypes and haplotypes respectively.,Nine new FCN2 variants including two with non synonymous substitutions in exon6 and exon8 were observed.,The homozygous genotypes +6424T/T were distributed more in controls and none in patients (P = 0.04).,The AGACG haplotype were observed more in patients than in controls (OR = 2.0, 95%CI 1.2-3.4, P = 0.006).,The serum ficolin-2 levels were significantly distributed among the reconstructed ficolin-2 haplotypes (P<0.008) and the haplotype AGACG was observed with higher ficolin-2 levels in 70 control individuals.,Our results demonstrate a significant association of FCN2 AGACG haplotype with cutaneous leishmaniasis in a Syrian Arab population.,These first results provide a basis for a future study that could confirm or disprove possible relationships between FCN2 gene polymorphisms with cutaneous leishmaniasis.

Molecular tools for detection of low-density asymptomatic Plasmodium infections are needed in malaria elimination efforts.,This study reports results from the hitherto largest implementation of loop-mediated isothermal amplification (LAMP) for centralized mass screening of asymptomatic malaria in Zanzibar.,Healthy individuals present and willing to participate in randomly selected households in 60 villages throughout Zanzibar were screened for malaria by rapid diagnostic tests (RDT).,In 50 % of the study households, participants were asked to provide 60 μL of finger-prick blood for additional LAMP screening.,LAMP was conducted in two centralized laboratories in Zanzibar, by trained technicians with limited or no previous experience of molecular methods.,The LAMP assay was performed with LoopampTM MALARIA Pan/Pf Detection Kit (Eiken Chemical Company, Japan).,Samples positive for Plasmodium genus (Pan)-LAMP were re-tested using Plasmodium falciparum-specific LAMP kits.,Paired RDT and LAMP samples were available from 3983 individuals.,The prevalence of asymptomatic malaria was 0.5 % (CI 95 % 0.1-0.8) and 1.6 % (CI 95 % 1.1-2.2) by RDT and Pan-LAMP, respectively.,LAMP detected 3.4 (CI 95 % 2.2-5.2) times more Plasmodium positive samples than RDT.,DNA contamination was experienced, but solved by repetitive decontamination of all equipment and reagents.,LAMP is a simple and sensitive molecular tool, and has potential in active surveillance and mass-screening programmes for detection of low-density asymptomatic malaria in pre-elimination settings.,However, in order to deploy LAMP more effectively in field settings, protocols may need to be adapted for processing larger numbers of samples.,A higher throughput, affordable closed system would be ideal to avoid contamination.,The online version of this article (doi:10.1186/s12936-015-0731-2) 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.

Strongyloides stercoralis infections have a worldwide distribution with a global burden in terms of prevalence and morbidity that is largely ignored.,A public health response against soil-transmitted helminth (STH) infections should broaden the strategy to include S. stercoralis and overcome the epidemiological, diagnostic, and therapeutic challenges that this parasite poses in comparison to Ascaris lumbricoides, Trichuris trichiura, and hookworms.,The relatively poor sensitivity of single stool evaluations, which is further lowered when quantitative techniques aimed at detecting eggs are used, also complicates morbidity evaluations and adequate drug efficacy measurements, since S. stercoralis is eliminated in stools in a larval stage.,Specific stool techniques for the detection of larvae of S. stercoralis, like Baermann's and Koga's agar plate, despite superiority over direct techniques are still suboptimal.,New serologies using recombinant antigens and molecular-based techniques offer new hopes in those areas.,The use of ivermectin rather than benzimidazoles for its treatment and the need to have curative regimens rather than lowering the parasite burden are also unique for S. stercoralis in comparison to the other STH due to its life cycle, which allows reproduction and amplification of the worm burden within the human host.,The potential impact on STH of the benzimidazoles/ivermectin combinations, already used for control/elimination of lymphatic filariasis, should be further evaluated in public health settings.,While waiting for more effective single-dose drug regimens and new sensitive diagnostics, the evidence and the tools already available warrant the planning of a common platform for STH and S. stercoralis control.

Morbidity due to Schistosoma haematobium and hookworm infections is marked in those with intense co-infections by these parasites.,The development of a spatial predictive decision-support tool is crucial for targeting the delivery of integrated mass drug administration (MDA) to those most in need.,We investigated the co-distribution of S. haematobium and hookworm infection, plus the spatial overlap of infection intensity of both parasites, in Ghana.,The aim was to produce maps to assist the planning and evaluation of national parasitic disease control programs.,A national cross-sectional school-based parasitological survey was conducted in Ghana in 2008, using standardized sampling and parasitological methods.,Bayesian geostatistical models were built, including a multinomial regression model for S. haematobium and hookworm mono- and co-infections and zero-inflated Poisson regression models for S. haematobium and hookworm infection intensity as measured by egg counts in urine and stool respectively.,The resulting infection intensity maps were overlaid to determine the extent of geographical overlap of S. haematobium and hookworm infection intensity.,In Ghana, prevalence of S. haematobium mono-infection was 14.4%, hookworm mono-infection was 3.2%, and S. haematobium and hookworm co-infection was 0.7%.,Distance to water bodies was negatively associated with S. haematobium and hookworm co-infections, hookworm mono-infections and S. haematobium infection intensity.,Land surface temperature was positively associated with hookworm mono-infections and S. haematobium infection intensity.,While high-risk (prevalence >10-20%) of co-infection was predicted in an area around Lake Volta, co-intensity was predicted to be highest in foci within that area.,Our approach, based on the combination of co-infection and co-intensity maps allows the identification of communities at increased risk of severe morbidity and environmental contamination and provides a platform to evaluate progress of control efforts.

Lotilaner is a novel isoxazoline developed for oral administration to dogs.,In laboratory studies, lotilaner was shown to be safe and to produce a rapid flea and tick knockdown, with a sustained speed of kill for at least a month post-treatment.,A study was undertaken to demonstrate the efficacy, safety and palatability of three monthly doses of lotilaner flavoured chewable tablets (Credelio™, Elanco) in controlling fleas under field conditions in Europe.,Dogs were enrolled at 17 veterinary clinics across Germany, Hungary and Portugal.,Qualifying households having no more than three dogs and one primary dog with at least five fleas was randomised 2:1 to a lotilaner (minimum dose rate 20 mg/kg) or a topical fipronil group (administered per label).,There were 128 and 64 households allocated to the lotilaner and fipronil groups, respectively.,Treatments were dispensed to owners on Days 0, 28 and 56; supplementary household dogs received the same treatment as the primary dog.,Post-enrollment flea counts and flea allergy dermatitis (FAD) assessments were made on primary dogs on Days 14, 28, 56 and 84.,Efficacy calculations were based on geometric mean percent reductions of live flea counts versus pre-treatment counts on Day 0.,The safety and palatability of lotilaner tablets were also assessed.,Lotilaner efficacy was 99.1, 99.5, 99.9 and 99.8% on Days 14, 28, 56 and 84, respectively.,Corresponding reductions for fipronil were 93.4, 91.2, 94.4 and 97.0%.,Lotilaner was superior to fipronil at all post-Day 0 assessments (t (186) ≥ 3.43, P ≤ 0.0007).,At every post-treatment assessment, at least 90% of lotilaner-treated dogs were flea-free (98.4% on Day 84); fewer than 90% of fipronil group dogs were flea-free on the same time points.,Lotilaner flavoured chewable tablets were palatable, and both products were well tolerated.,Lotilaner alleviated or eliminated clinical signs of FAD, including pruritus.,Under field conditions in Europe, lotilaner flavoured chewable tablets were greater than 99% effective in eliminating fleas from dogs at the first post-treatment assessment (Day 14).,Efficacy was maintained through Day 84, with corresponding improvements in FAD.,Lotilaner tablets were palatable and safe and provided superior flea control to fipronil.,The online version of this article (10.1186/s13071-017-2479-8) contains supplementary material, which is available to authorized users.

With the geographical expansion of tick species and increased recognition of pathogens they transmit, there is a requirement for safe and rapidly effective control measures for dogs.,Lotilaner, a novel isoxazoline, is rapidly absorbed following administration of a flavored chewable tablet formulation (Credelio™), providing at least 98% efficacy for at least 1 month following assessments at 48 h post-treatment, and following subsequent challenges.,A study was conducted to determine the speed with which lotilaner kills ticks.,From 38 dogs, the 32 with the highest Ixodes ricinus counts from a Day -4 infestation were randomized among four groups: two groups were untreated controls, two received lotilaner tablets at a minimum dose rate of 20 mg/kg.,Infestations with I. ricinus were performed on Days -2, 7, 14, 21, 28 and 35.,Counts were completed 4 and 8 h post-treatment (Day 0), and 8 and 12 h following subsequent infestations.,All live ticks were incubated for 24 h following removal from study dogs.,At 4 h post-treatment, there was a 69.8% reduction in geometric mean live tick counts in treated dogs compared to controls.,After incubation, the reduction increased to 97.2%.,At 8 h after treatment, pre- and post-incubation reductions were 99.2 and 100%, respectively.,Following post-treatment challenges, post-incubation efficacy through Day 28 at 8 and 12 h was at least 94.3 and 98.0%, respectively, and was 85.7 and 94.2% at 8 and 12 h after the Day 35 challenge.,Mean live tick counts in the lotilaner groups were significantly lower than in the control groups at all assessments through Day 35 at 8 (t (7) ≥ 9, P < 0.0001, Days 0 to 28; t (7) = 3.54, P ≤ 0.0095, Day 35) and 12 h post-treatment and after subsequent infestations (t (7) ≥ 10, P < 0.0001, all days).,There were no treatment-related adverse events.,Lotilaner at a minimum dose rate of 20 mg/kg began to kill ticks on dogs within 4 h of treatment and efficacy was 100% within 8 h.,Lotilaner sustained a rapid kill of newly infesting I. ricinus through 35 days.,By quickly killing ticks that infest dogs, lotilaner has potential to help limit the transmission of tick-borne pathogens.,The online version of this article (10.1186/s13071-017-2467-z) 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.

Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission.,Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure.,This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas.,We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic), and measured T. cruzi prevalence, and host feeding sources of triatomines.,Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat.,Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana.,In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season.,Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human) and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi.,Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence.,Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape.,This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats.

Trypanosoma cruzi (T. cruzi) is the etiological agent of Chagas cardiomyopathy.,In the present study, we investigated the role of extracellular vesicles (Ev) in shaping the macrophage (Mφ) response in progressive Chagas disease (CD).,We purified T. cruzi Ev (TcEv) from axenic parasite cultures, and T. cruzi-induced Ev (TEv) from the supernatants of infected cells and plasma of acutely and chronically infected wild-type and Parp1-/- mice.,Cultured (Raw 264.7) and bone-marrow Mφ responded to TcEV and TEv with a profound increase in the expression and release of TNF-α, IL-6, and IL-1β cytokines.,TEv produced by both immune (Mφ) and non-immune (muscle) cells were proinflammatory.,Chemical inhibition or genetic deletion of PARP1 (a DNA repair enzyme) significantly depressed the TEv-induced transcriptional and translational activation of proinflammatory Mφ response.,Oxidized DNA encapsulated by TEv was necessary for PARP1-dependent proinflammatory Mφ response.,Inhibition studies suggested that DNA-sensing innate immune receptors (cGAS>>TLR9) synergized with PARP1 in signaling the NFκB activation, and inhibition of PARP1 and cGAS resulted in >80% inhibition of TEv-induced NFκB activity.,Histochemical studies showed intense inflammatory infiltrate associated with profound increase in CD11b+CD68+TNF-α+ Mφ in the myocardium of CD wild-type mice.,In comparison, chronically infected Parp1-/- mice exhibited low-to-moderate tissue inflammation, >80% decline in myocardial infiltration of TNF-α+ Mφ, and no change in immunoregulatory IL-10+ Mφ.,We conclude that oxidized DNA released with TEv signal the PARP1-cGAS-NF-κB pathway of proinflammatory Mφ activation and worsens the chronic inflammatory pathology in CD.,Small molecule antagonists of PARP1-cGAS signaling pathway would potentially be useful in reprogramming the Mφ activation and controlling the chronic inflammation in CD.

Prevention of Trypanosoma cruzi infection in mammals likely depends on either prevention of the invading trypomastigotes from infecting host cells or the rapid recognition and killing of the newly infected cells by T. cruzi-specific T cells.,We show here that multiple rounds of infection and cure (by drug therapy) fails to protect mice from reinfection, despite the generation of potent T cell responses.,This disappointing result is similar to that obtained with many other vaccine protocols used in attempts to protect animals from T. cruzi infection.,We have previously shown that immune recognition of T. cruzi infection is significantly delayed both at the systemic level and at the level of the infected host cell.,The systemic delay appears to be the result of a stealth infection process that fails to trigger substantial innate recognition mechanisms while the delay at the cellular level is related to the immunodominance of highly variable gene family proteins, in particular those of the trans-sialidase family.,Here we discuss how these previous studies and the new findings herein impact our thoughts on the potential of prophylactic vaccination to serve a productive role in the prevention of T. cruzi infection and Chagas disease.

In this study, ticks from pastoral communities in Kenya were tested for Rickettsia spp. infections in geographical regions where the presence of tick-borne arboviruses had previously been reported.,Rickettsial and arbovirus infections have similar clinical features which makes differential diagnosis challenging when both diseases occur.,The tick samples were tested for Rickettsia spp. by conventional PCR using three primer sets targeting the gltA, ompA, and ompB genes followed by amplicon sequencing.,Of the tick pools screened, 25% (95/380) were positive for Rickettsia spp.,DNA using the gltA primer set.,Of the tick-positive pools, 60% were ticks collected from camels.,Rickettsia aeschlimannii and R. africae were the main Rickettsia spp. detected in the tick pools sequenced.,The findings of this study indicate that multiple Rickettsia species are circulating in ticks from pastoral communities in Kenya and could contribute to the etiology of febrile illness in these areas.,Diagnosis and treatment of rickettsial infections should be a public health priority in these regions.

Following the deployment of new recommendations for malaria control according to the World Health Organization, an estimation of the real burden of the disease is needed to better identify populations at risk and to adapt control strategies.,The aim of the present study was to estimate the clinical burden of malaria among febrile children aged less than 11 years, before and after six-year of deployment of malaria control strategies in different areas of Gabon.,Cross-sectional surveys were carried out in health care facilities at four locations: two urban areas (Libreville and Port-Gentil), one semi-urban area (Melen) and one rural area (Oyem), between 2005 and 2011.,Febrile paediatric patients, aged less than 11 years old were screened for malaria using microscopy.,Body temperature, history of fever, age, sex, and location were collected.,A total of 16,831 febrile children were enrolled; 78.5% (n=13,212) were less than five years old.,The rate of Plasmodium falciparum-infection was the lowest in Port-gentil (below 10%) and the highest at Oyem (above 35%).,Between 2005 and 2008, malaria prevalence dropped significantly from 31.2% to 18.3%, followed by an increase in 2011 in Libreville (24.1%), Port-Gentil (6.5%) and Oyem (44.2%) (p<0.01).,Median age among the infected patients increased throughout the study period reaching 84 (60-108) months in Libreville in 2011 (p<0.01).,From 2008, at all sites, children older than five years were more frequently infected; the risk of being infected significantly increased with time, ranging from 0.37 to 1.50 in 2005 and from 2.03 to 5.10 in 2011 in this group (p<0.01).,The risk of being P. falciparum-infected in children aged less than five years old significantly decreased from 2008 to 2011 (p<0.01).,This study shows an increased risk of malaria infection in different areas of Gabon with over-five year-old children tending to become the most at-risk population, suggesting a changing epidemiology.,Moreover, the heterogeneity of the malaria burden in the country highlights the importance of maintaining various malaria control strategies and redefining their implementation.

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.

As some malaria control programs shift focus from disease control to transmission reduction, there is a need for transmission data to monitor progress.,At lower levels of transmission, it becomes increasingly more difficult to measure precisely, for example through entomological studies.,Many programs conduct regular cross sectional parasite prevalence surveys, and have access to malaria treatment data routinely collected by ministries of health, often in health management information systems.,However, by themselves, these data are poor measures of transmission.,In this paper, we propose an approach for combining annual parasite incidence and treatment data with cross-sectional parasite prevalence and treatment seeking survey data to estimate the incidence of new infections in the human population, also known as the force of infection.,The approach is based on extension of a reversible catalytic model.,The accuracy of the estimates from this model appears to be highly dependent on levels of detectability and treatment in the community, indicating the importance of information on private sector treatment seeking and access to effective and appropriate treatment.

Modern controlled human malaria infection (CHMI) clinical trials have almost entirely focussed on Plasmodium falciparum, providing a highly informative means to investigate host-pathogen interactions as well as assess potential new prophylactic and therapeutic interventions.,However, in recent years, there has been renewed interest in Plasmodium vivax, with CHMI models developed by groups in Colombia, the USA, and Australia.,This review summarizes the published experiences, and examines the advantages and disadvantages of the different models that initiate infection either by mosquito bite or using a blood-stage inoculum.,As for P. falciparum, CHMI studies with P. vivax will provide a platform for early proof-of-concept testing of drugs and vaccines, accelerating the development of novel interventions.

Plasmodium vivax infects a hundred million people annually and endangers 40% of the world's population.,Unlike Plasmodium falciparum, P. vivax parasites can persist as a dormant stage in the liver, known as the hypnozoite, and these dormant forms can cause malaria relapses months or years after the initial mosquito bite.,Here we analyze whole genome sequencing data from parasites in the blood of a patient who experienced consecutive P. vivax relapses over 33 months in a non-endemic country.,By analyzing patterns of identity, read coverage, and the presence or absence of minor alleles in the initial polyclonal and subsequent monoclonal infections, we show that the parasites in the three infections are likely meiotic siblings.,We infer that these siblings are descended from a single tetrad-like form that developed in the infecting mosquito midgut shortly after fertilization.,In this natural cross we find the recombination rate for P. vivax to be 10 kb per centimorgan and we further observe areas of disequilibrium surrounding major drug resistance genes.,Our data provide new strategies for studying multiclonal infections, which are common in all types of infectious diseases, and for distinguishing P. vivax relapses from reinfections in malaria endemic regions.,This work provides a theoretical foundation for studies that aim to determine if new or existing drugs can provide a radical cure of P. vivax malaria.

Plasmodium sporozoites are transmitted from infected mosquitoes to mammals, and must navigate the host skin and vasculature to infect the liver.,This journey requires distinct proteomes.,Here, we report the dynamic transcriptomes and proteomes of both oocyst sporozoites and salivary gland sporozoites in both rodent-infectious Plasmodium yoelii parasites and human-infectious Plasmodium falciparum parasites.,The data robustly define mRNAs and proteins that are upregulated in oocyst sporozoites (UOS) or upregulated in infectious sporozoites (UIS) within the salivary glands, including many that are essential for sporozoite functions in the vector and host.,Moreover, we find that malaria parasites use two overlapping, extensive, and independent programs of translational repression across sporozoite maturation to temporally regulate protein expression.,Together with gene-specific validation experiments, these data indicate that two waves of translational repression are implemented and relieved at different times during sporozoite maturation, migration and infection, thus promoting their successful development and vector-to-host transition.,Here, the authors report transcriptomes and proteomes of oocyst sporozoite and salivary gland sporozoite stages in rodent-infectious Plasmodium yoelii parasites and human infectious Plasmodium falciparum parasites and define two waves of translational repression during sporozoite maturation.

Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia.,Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias.,Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias.,Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated.,A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated.,To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high.,Predictions were then made throughout Southeast Asia, including regions where infection data are sparse.,The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam) as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines).,We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk.,Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence.,Considering malaria elimination goals, areas for prioritised surveillance are identified.

The potential benefits of Mass Drug Administration (MDA) for malaria elimination are being considered in several malaria endemic countries where a decline in malaria transmission has been reported.,For this strategy to work, it is important that a large proportion of the target population participates, requiring an in-depth understanding of factors that may affect participation and adherence to MDA programs.,This social science study was ancillary to a one-round directly observed MDA campaign with dihydroartemisinin-piperaquine, carried out in 12 villages in rural Gambia between June and August 2014.,The social science study employed a mixed-methods approach combining qualitative methods (participant observation and in-depth interviewing) and quantitative methods (structured follow-up interviews among non-participating and non-adhering community members).,Of 3942 people registered in the study villages, 67.9% adhered to the three consecutive daily doses.,For the remaining villagers, 12.6% did not attend the screening, 3.5% was not eligible and 16% did not adhere to the treatment schedule.,The main barriers for non-participation and adherence were long and short-term mobility of individuals and specific subgroups, perceived adverse drug reactions and rumors, inconveniences related to the logistics of MDA (e.g. waiting times) and the perceived lack of information about MDA.,While, there was no fundamental resistance from the target communities, adherence was 67.9%.,This shows the necessity of understanding local perceptions and barriers to increase its effectiveness.,Moreover, certain of the constraining factors were socio-spatially clustered which might prove problematic since focal areas of residual malaria transmission may remain allowing malaria to spread to adjacent areas where transmission had been temporarily interrupted.

A substantial decline in malaria was reported to have occurred over several years until 2007 in the western part of The Gambia, encouraging consideration of future elimination in this previously highly endemic region.,Scale up of interventions has since increased with support from the Global Fund and other donors.,We continued to examine laboratory records at four health facilities previously studied and investigated six additional facilities for a 7 year period, adding data from 243,707 slide examinations, to determine trends throughout the country until the end of 2009.,We actively detected infections in a community cohort of 800 children living in rural villages throughout the 2008 malaria season, and assayed serological changes in another rural population between 2006 and 2009.,Proportions of malaria positive slides declined significantly at all of the 10 health facilities between 2003 (annual mean across all sites, 38.7%) and 2009 (annual mean, 7.9%).,Statistical modelling of trends confirmed significant seasonality and decline over time at each facility.,Slide positivity was lowest in 2009 at all sites, except two where lowest levels were observed in 2006.,Mapping households of cases presenting at the latter sites in 2007-2009 indicated that these were not restricted to a few residual foci.,Only 2.8% (22/800) of a rural cohort of children had a malaria episode in the 2008 season, and there was substantial serological decline between 2006 and 2009 in a separate rural area.,Malaria has continued to decline in The Gambia, as indicated by a downward trend in slide positivity at health facilities, and unprecedented low incidence and seroprevalence in community surveys.,We recommend intensification of control interventions for several years to further reduce incidence, prior to considering an elimination programme.

Sanaria Inc. has developed methods to manufacture, purify and cryopreserve aseptic Plasmodium falciparum (Pf) sporozoites (SPZ), and is using this platform technology to develop an injectable PfSPZ-based vaccine that provides high-grade, durable protection against infection with Pf malaria.,Several candidate vaccines are being developed and tested, including PfSPZ Vaccine, in which the PfSPZ are attenuated by irradiation, PfSPZ-CVac, in which fully infectious PfSPZ are attenuated in vivo by concomitant administration of an anti-malarial drug, and PfSPZ-GA1, in which the PfSPZ are attenuated by gene knockout.,Forty-three research groups in 15 countries, organized as the International PfSPZ Consortium (I-PfSPZ-C), are collaborating to advance this program by providing intellectual, clinical, and financial support.,Fourteen clinical trials of these products have been completed in the USA, Europe and Africa, two are underway and at least 12 more are planned for 2015-2016 in the US (four trials), Germany (2 trials), Tanzania, Kenya, Mali, Burkina Faso, Ghana and Equatorial Guinea.,Sanaria anticipates application to license a first generation product as early as late 2017, initially to protect adults, and a year later to protect all persons >6 months of age for at least six months.,Improved vaccine candidates will be advanced as needed until the following requirements have been met: long-term protection against natural transmission, excellent safety and tolerability, and operational feasibility for population-wide administration.,Here we describe the three most developed whole PfSPZ vaccine candidates, associated clinical trials, initial plans for licensure and deployment, and long-term objectives for a final product suitable for mass administration to achieve regional malaria elimination and eventual global eradication.

Immunization of volunteers under chloroquine prophylaxis by bites of Plasmodium falciparum sporozoite (PfSPZ)-infected mosquitoes induces > 90% protection against controlled human malaria infection (CHMI).,We studied intradermal immunization with cryopreserved, infectious PfSPZ in volunteers taking chloroquine (PfSPZ chemoprophylaxis vaccine [CVac]).,Vaccine groups 1 and 3 received 3× monthly immunizations with 7.5 × 104 PfSPZ.,Control groups 2 and 4 received normal saline.,Groups 1 and 2 underwent CHMI (#1) by mosquito bite 60 days after the third immunization.,Groups 3 and 4 were boosted 168 days after the third immunization and underwent CHMI (#2) 137 days later.,Vaccinees (11/20, 55%) and controls (6/10, 60%) had the same percentage of mild to moderate solicited adverse events.,After CHMI #1, 8/10 vaccinees (group 1) and 5/5 controls (group 2) became parasitemic by microscopy; the two negatives were positive by quantitative real-time polymerase chain reaction (qPCR).,After CHMI #2, all vaccinees in group 3 and controls in group 4 were parasitemic by qPCR.,Vaccinees showed weak antibody and no detectable cellular immune responses.,Intradermal immunization with up to 3 × 105 PfSPZ-CVac was safe, but induced only minimal immune responses and no sterile protection against Pf CHMI.

In Sub-Saharan Africa, urogenital schistosomiasis remains a significant public health problem, causing 150.000 deaths/year with approximately 112 million cases diagnosed.,The Niakhar district is a disease hotspot in central Senegal where transmission occurs seasonally with high prevalences.,The aim of this study was to determine the effect of annual treatment over 3 years on the seasonal transmission dynamics of S. haematobium in 9 villages in the Niakhar district.,Adults and children aged between 5 and 60 years were surveyed from 2011 to 2014.,Urine samples were collected door-to-door and examined for S. haematobium eggs at baseline in June 2011, and all participants were treated in August 2011 with PZQ (40 mg/kg).,After this initial examination, evaluations were conducted at 3 successive time points from September 2011 to March 2014, to measure the efficacy of the annual treatments and the rates of reinfection.,Each year, during the transmission period, from July to November-December, malacological surveys were also carried out in the fresh water bodies of each village to evaluate the infestation of the snail intermediate hosts.,At baseline, the overall prevalence of S. haematobium infection was 57.7%, and the proportion of heavy infection was 45.3%, but one month after the first treatment high cure rates (92.9%) were obtained.,The overall infection prevalence and proportion of heavy infection intensities were drastically reduced to 4.2% and 2.3%, respectively.,The level of the first reinfection in February-March 2012 was 9.5%.,At follow-up time points, prevalence levels varied slightly between reinfection and treatment from 9.5% in June 2012 to 0.3% in March 2013, 11.2 in June 2013, and 10.1% April 2014.,At the end of the study, overall prevalence was significantly reduced from 57.7% to 10.1%.,The overall rate of infested Bulinid snails was reduced after repeated treatment from 0.8% in 2012 to 0.5% in 2013.,Repeated annual treatments are suggested to have a considerable impact on the transmission dynamics of S. haematobium in Niakhar, due to the nature of the epidemiological system with seasonal transmission.,Thus, to maintain this benefit and continue to reduce the morbidity of urogenital schistosomiasis, other approaches should be integrated into the strategy plans of the National program to achieve the goal of urogenital schistosomiasis elimination in seasonal foci in Senegal.

To assess the impact of a decade of biennial mass administration of praziquantel on schistosomiasis in school-age children in Burkina Faso.,In 2013, in a national assessment based on 22 sentinel sites, 3514 school children aged 7-11 years were checked for Schistosoma haematobium and Schistosoma mansoni infection by the examination of urine and stool samples, respectively.,We analysed the observed prevalence and intensity of infections and compared these with the relevant results of earlier surveys in Burkina Faso.,S. haematobium was detected in 287/3514 school children (adjusted prevalence: 8.76%, range across sentinel sites: 0.0-56.3%; median: 2.5%).,The prevalence of S. haematobium infection was higher in the children from the Centre-Est, Est and Sahel regions than in those from Burkina Faso’s other eight regions with sentinel sites (P < 0.001).,The adjusted arithmetic mean intensity of S. haematobium infection, among all children, was 6.0 eggs per 10 ml urine.,Less than 1% of the children in six regions had heavy S. haematobium infections - i.e. at least 50 eggs per 10 ml urine - but such infections were detected in 8.75% (28/320) and 11.56% (37/320) of the children from the Centre-Est and Sahel regions, respectively.,Schistosoma mansoni was only detected in two regions and 43 children - i.e.,1 (0.31%) of the 320 from Centre-Sud and 42 (8.75%) of the 480 from Hauts Bassins.,By mass use of preventive chemotherapy, Burkina Faso may have eliminated schistosomiasis as a public health problem in eight regions and controlled schistosome-related morbidity in another three regions.

Type I interferon (IFN) is critical for controlling pathogen infection; however, its regulatory mechanisms in plasmacytoid cells (pDCs) still remain unclear.,Here, we have shown that nucleic acid sensors cGAS-, STING-, MDA5-, MAVS-, or transcription factor IRF3-deficient mice produced high amounts of type I IFN-α and IFN-β (IFN-α/β) in the serum and were resistant to lethal plasmodium yoelii YM infection.,Robust IFN-α/β production was abolished when gene encoding nucleic acid sensor TLR7, signaling adaptor MyD88, or transcription factor IRF7 was ablated or pDCs were depleted.,Further, we identified SOCS1 as a key negative regulator to inhibit MyD88-dependent type I IFN signaling in pDCs.,Finally, we have demonstrated that pDCs, cDCs, and macrophages were required for generating IFN-α/β-induced subsequent protective immunity.,Thus, our findings have identified a critical regulatory mechanism of type I IFN signaling in pDCs and stage-specific function of immune cells in generating potent immunity against lethal YM infection.,•cGAS functions as a DNA sensor in vivo for detecting malaria genomic DNA•STING- and MAVS-mediated signaling induces a negative regulator SOCS1 expression•SOCS1 inhibits MyD88-mediated type I IFN signaling in pDCs•Type I IFN produced by pDCs activates cDCs and macrophages for adaptive immunity,cGAS functions as a DNA sensor in vivo for detecting malaria genomic DNA,STING- and MAVS-mediated signaling induces a negative regulator SOCS1 expression,SOCS1 inhibits MyD88-mediated type I IFN signaling in pDCs,Type I IFN produced by pDCs activates cDCs and macrophages for adaptive immunity,Malaria is a worldwide deadly infectious disease; how type I IFN signaling is regulated in response to malaria infection remains poorly understood.,Yu et al. identify a cross-regulatory mechanism of two type I IFN signaling pathways in plasmacytoid DCs, which is critical for generating protective immunity against lethal malaria infection.

The influence of parasite genetic factors on immune responses and development of severe pathology of malaria is largely unknown.,In this study, we performed genome-wide transcriptomic profiling of mouse whole blood during blood-stage infections of two strains of the rodent malaria parasite Plasmodium chabaudi that differ in virulence.,We identified several transcriptomic signatures associated with the virulent infection, including signatures for platelet aggregation, stronger and prolonged anemia and lung inflammation.,The first two signatures were detected prior to pathology.,The anemia signature indicated deregulation of host erythropoiesis, and the lung inflammation signature was linked to increased neutrophil infiltration, more cell death and greater parasite sequestration in the lungs.,This comparative whole-blood transcriptomics profiling of virulent and avirulent malaria shows the validity of this approach to inform severity of the infection and provide insight into pathogenic mechanisms.

Chloroquine is the first-line treatment for Plasmodium vivax malaria in most endemic countries, but resistance is increasing.,Monitoring of antimalarial efficacy is essential, but in P vivax infections the assessment of treatment efficacy is confounded by relapse from the dormant liver stages.,We systematically reviewed P vivax malaria treatment efficacy studies to establish the global extent of chloroquine resistance.,We searched Medline, Web of Science, Embase, and the Cochrane Database of Systematic Reviews to identify studies published in English between Jan 1, 1960, and April 30, 2014, which investigated antimalarial treatment efficacy in P vivax malaria.,We excluded studies that did not include supervised schizonticidal treatment without primaquine.,We determined rates of chloroquine resistance according to P vivax malaria recurrence rates by day 28 whole-blood chloroquine concentrations at the time of recurrence and study enrolment criteria.,We identified 129 eligible clinical trials involving 21 694 patients at 179 study sites and 26 case reports describing 54 patients.,Chloroquine resistance was present in 58 (53%) of 113 assessable study sites, spread across most countries that are endemic for P vivax.,Clearance of parasitaemia assessed by microscopy in 95% of patients by day 2, or all patients by day 3, was 100% predictive of chloroquine sensitivity.,Heterogeneity of study design and analysis has confounded global surveillance of chloroquine-resistant P vivax, which is now present across most countries endemic for P vivax.,Improved methods for monitoring of drug resistance are needed to inform antimalarial policy in these regions.,Wellcome Trust (UK).

Chloroquine (CQ), a cost effective antimalarial drug with a relatively good safety profile and therapeutic index, is no longer used by itself to treat patients with Plasmodium falciparum due to CQ-resistant strains.,P. vivax, representing over 90% of malaria cases in Brazil, despite reported resistance, is treated with CQ as well as with primaquine to block malaria transmission and avoid late P. vivax malaria relapses.,Resistance to CQ and other antimalarial drugs influences malaria control, thus monitoring resistance phenotype by parasite genotyping is helpful in endemic areas.,A total of 47 P. vivax and nine P. falciparum fresh isolates were genetically characterized and tested for CQ, mefloquine (MQ) and artesunate (ART) susceptibility in vitro.,The genes mdr1 and pfcrt, likely related to CQ resistance, were analyzed in all isolates.,Drug susceptibility was determined using short-term parasite cultures of ring stages for 48 to 72 hour and thick blood smears counts.,Each parasite isolate was tested with the antimalarials to measure the geometric mean of 50% inhibitory concentration.,The low numbers of P. falciparum isolates reflect the species prevalence in Brazil; most displayed low sensitivity to CQ (IC50 70 nM).,However, CQ resistance was rare among P. vivax isolates (IC50 of 32 nM).,The majority of P. vivax and P. falciparum isolates were sensitive to ART and MQ.,One hundred percent of P. falciparum isolates carried non-synonymous mutations in the pfmdr1 gene in codons 184, 1042 and 1246, 84% in codons 1034 and none in codon 86, a well-known resistance mutation.,For the pfcrt gene, mutations were observed in codons 72 and 76 in all P. falciparum isolates.,One P. falciparum isolate from Angola, Africa, showing sensitivity to the antimalarials, presented no mutations.,In P. vivax, mutations of pvmdr1 and the multidrug resistance gene 1 marker at codon F976 were absent.,All P. falciparum Brazilian isolates showed CQ resistance and presented non-synonymous mutations in pfmdr1 and pfcrt.,CQ resistant genotypes were not present among P. vivax isolates and the IC50 values were low in all samples of the Brazilian West Amazon.

In the Greater Mekong Subregion, adults are at highest risk for malaria.,The most relevant disease vectors bite during daytime and outdoors which makes forest work a high-risk activity for malaria.,The absence of effective vector control strategies and limited periods of exposure during forest visits suggest that chemoprophylaxis could be an appropriate strategy to protect forest goers against malaria.,The protocol describes an open-label randomised controlled trial of artemether-lumefantrine (AL) versus multivitamin as prophylaxis against malaria among forest goers aged 16-65 years in rural northeast Cambodia.,The primary objective is to compare the efficacy of the artemisinin combination therapy AL versus a multivitamin preparation as defined by the 28-day PCR parasite positivity rate and incidence of confirmed clinical malaria of any species.,The sample size is 2200 patient-episodes of duration 1 month in each arm.,The duration of follow-up and prophylaxis for each participant is 1, 2 or 3 consecutive 28-day periods, followed by a further 28 days of post-exposure prophylaxis, depending on whether they continue to visit the forest.,Analysis will be done both by intention to treat and per protocol.,All participants will provide written, informed consent.,Ethical approval was obtained from the Oxford Tropical Research Ethics Committee and the Cambodia National Ethics Committee for Health Research.,Results will be disseminated by peer-reviewed open access publication together with open data.,NCT04041973; Pre-result.

Over the last 20 years, malaria incidence has decreased across the Greater Mekong Sub-region (GMS) and the emergence of artemisinin resistance has stimulated efforts to accelerate regional elimination.,In the GMS, the malaria transmission is focused increasingly in forested zones.,This article describes forest-going activities and examines forest workers’ attitudes to and experiences of malaria prevention and control in north-eastern Cambodia.,In Stung Treng Province, Cambodia, 19 in-depth interviews were conducted in villages with participants recently diagnosed with uncomplicated falciparum malaria who reported working in forests.,Two focus group discussions with respondents’ forest-working peers were held.,Interviews and focus groups were audio-recorded transcribed, and translated for thematic analysis.,Forest work is an essential source of income for respondents.,Many combine it with farming, which influences the timing and duration of forest visits.,Forest activities include logging and collecting other forest products, particularly malva nuts.,Men log year-round, whereas gathering forest products is seasonal and can involve entire families.,Forest workers sleep chiefly in unimpregnated hammock nets in make-shift encampments.,Respondents are concerned about symptomatic malaria, but unfamiliar with the concept of asymptomatic infection.,They view the forest as an area of potential malaria infection and seek to protect themselves from mosquito bites through wearing long-sleeved clothes, using repellents, and lighting fires.,Forest workers express a willingness to self-test and self-administer anti-malarials.,Forest workers’ behaviour and perceptions of risk indicate that improvements are needed to current control measures.,There is potential to: better target distribution of impregnated hammock nets; offer curative or presumptive treatment while in forests; and expand access to screening.,Establishing the efficacy and feasibility of prophylaxis for forest workers in the GMS is a priority.

In Côte d’Ivoire, an estimated 767,000 disability-adjusted life years are due to malaria, placing the country at position number 14 with regard to the global burden of malaria.,Risk maps are important to guide control interventions, and hence, the aim of this study was to predict the geographical distribution of malaria infection risk in children aged <16 years in Côte d’Ivoire at high spatial resolution.,Using different data sources, a systematic review was carried out to compile and geo-reference survey data on Plasmodium spp. infection prevalence in Côte d’Ivoire, focusing on children aged <16 years.,The period from 1988 to 2007 was covered.,A suite of Bayesian geo-statistical logistic regression models was fitted to analyse malaria risk.,Non-spatial models with and without exchangeable random effect parameters were compared to stationary and non-stationary spatial models.,Non-stationarity was modelled assuming that the underlying spatial process is a mixture of separate stationary processes in each ecological zone.,The best fitting model based on the deviance information criterion was used to predict Plasmodium spp. infection risk for entire Côte d’Ivoire, including uncertainty.,Overall, 235 data points at 170 unique survey locations with malaria prevalence data for individuals aged <16 years were extracted.,Most data points (n = 182, 77.4%) were collected between 2000 and 2007.,A Bayesian non-stationary regression model showed the best fit with annualized rainfall and maximum land surface temperature identified as significant environmental covariates.,This model was used to predict malaria infection risk at non-sampled locations.,High-risk areas were mainly found in the north-central and western area, while relatively low-risk areas were located in the north at the country border, in the north-east, in the south-east around Abidjan, and in the central-west between two high prevalence areas.,The malaria risk map at high spatial resolution gives an important overview of the geographical distribution of the disease in Côte d’Ivoire.,It is a useful tool for the national malaria control programme and can be utilized for spatial targeting of control interventions and rational resource allocation.

Previous studies investigating the travellers’ knowledge, attitudes and practices (KAP) profile indicated an important educational need among those travelling to risk destinations.,Initiatives to improve such education should target all groups of travellers, including business travellers, those visiting friends and relatives (VFRs), and elderly travellers.,In the years 2002 to 2009, a questionnaire-based survey was conducted at the Dutch Schiphol Airport with the aim to study trends in KAP of travel risk groups towards prevention of malaria.,The risk groups last-minute travellers, solo-travellers, business travellers, VFRs and elderly travellers were specifically studied.,A total of 3,045 respondents were included in the survey.,Travellers to destinations with a high risk for malaria had significantly more accurate risk perceptions (knowledge) than travellers to low-risk destinations.,The relative risk for malaria in travellers to high-risk destinations was probably mitigated by higher protection rates against malaria as compared with travellers to low risk destinations.,There were no significant differences in intended risk-taking behaviour.,Trend analyses showed a significant change over time in attitude towards more risk-avoiding behaviour and towards higher protection rates against malaria in travellers to high-risk destinations.,The KAP profile of last-minute travellers substantially increased their relative risk for malaria, which contrasts to the slight increase in relative risk of solo travellers, business travellers and VFRs for malaria.,The results of this sequential cohort survey in Dutch travellers suggest an annual 1.8% increase in protection rates against malaria coinciding with an annual 2.5% decrease in intended risk-seeking behaviour.,This improvement may reflect the continuous efforts of travel health advice providers to create awareness and to propagate safe and healthy travel.,The KAP profile of last-minute travellers, in particular, substantially increased their relative risk for malaria, underlining the continuous need for personal protective measures and malaria chemoprophylaxis for this risk group.

Local and cross-border importation remain major challenges to malaria elimination and are difficult to measure using traditional surveillance data.,To address this challenge, we systematically collected parasite genetic data and travel history from thousands of malaria cases across northeastern Namibia and estimated human mobility from mobile phone data.,We observed strong fine-scale spatial structure in local parasite populations, providing positive evidence that the majority of cases were due to local transmission.,This result was largely consistent with estimates from mobile phone and travel history data.,However, genetic data identified more detailed and extensive evidence of parasite connectivity over hundreds of kilometers than the other data, within Namibia and across the Angolan and Zambian borders.,Our results provide a framework for incorporating genetic data into malaria surveillance and provide evidence that both strengthening of local interventions and regional coordination are likely necessary to eliminate malaria in this region of Southern Africa.,The number of malaria cases has dropped in some Southern Africa countries, but others still remain seriously affected.,When people travel within and between countries, they can bring the parasites that cause the disease to different areas.,This can fuel local transmission or even lead to outbreaks in a malaria-free area.,When new malaria patients are diagnosed, they are often asked to report their recent travel history, so that the origin of their infection can be tracked.,In theory, this would help to spot regions where the disease is imported from, and design targeted interventions.,However, it is difficult to know exactly where the parasites come from based on self-disclosed travel history.,At best, this history can provide information about that persons infection but nothing further in the past; at worst this history can be completely incorrect.,Parasite DNA, on the other hand, has the potential to bring with it an indelible record of the past.,To address the problem of determining where malaria infections came from, Tessema, Wesolowski et al. focused on Northern Namibia, a region where malaria persists despite being practically absent from the rest of the country.,Patients movements were assessed using mobile phone call records as well as self-reported travel history In addition, samples a single drop of blood were taken so that the genetic information of the parasites could be examined.,Combining genetic data with travel history and phone records, Tessema, Wesolowski et al. found that, in Northern Namibia, most people had gotten infected by malaria locally.,However, the genetic analyses also revealed that certain infections came from places across the Angolan and Zambian borders, information that was much more difficult to obtain using self-report or mobile phone data.,A new, separate study by Chang et al. also supports these results, showing that, in Bangladesh, combining genetic data with travel history and mobile phone records helps to track how malaria spreads.,Overall, the work by Tessema, Wesolowski et al. indicate that, in Northern Namibia, it will be necessary to strengthen local interventions to eliminate malaria.,However, different countries in the region may also need to coordinate to decrease malaria nearby and reduce the number of cases coming into the country.,While genetic data can help to monitor how new malaria cases are imported, this knowledge will be most valuable if it is routinely collected across countries.,New tools will also be required to translate genetic data into information that can easily be used for control and elimination programs.

Deforestation is associated with elevated risk for malaria in the Amazon.,Malaria is the most prevalent vector-borne disease in the Amazon.,We used malaria reports for health districts collected in 2006 by the Programa Nacional de Controle da Malária to determine whether deforestation is associated with malaria incidence in the county (município) of Mâncio Lima, Acre State, Brazil.,Cumulative percent deforestation was calculated for the spatial catchment area of each health district by using 60 × 60-meter, resolution-classified imagery.,Statistical associations were identified with univariate and multivariate general additive negative binomial models adjusted for spatial effects.,Our cross-sectional study shows malaria incidence across health districts in 2006 is positively associated with greater changes in percentage of cumulative deforestation within respective health districts.,After adjusting for access to care, health district size, and spatial trends, we show that a 4.3%, or 1 SD, change in deforestation from August 1997 through August 2000 is associated with a 48% increase of malaria incidence.

Current malaria control strategies recommend (i) early case detection using rapid diagnostic tests (RDT) and treatment with artemisinin combination therapy (ACT), (ii) pre-referral rectal artesunate, (iii) intermittent preventive treatment and (iv) impregnated bed nets.,However, these individual malaria control interventions provide only partial protection in most epidemiological situations.,Therefore, there is a need to investigate the potential benefits of integrating several malaria interventions to reduce malaria prevalence and morbidity.,A randomized controlled trial was carried out to assess the impact of combining seasonal intermittent preventive treatment in children (IPTc) with home-based management of malaria (HMM) by community health workers (CHWs) in Senegal.,Eight CHWs in eight villages covered by the Bonconto health post, (South Eastern part of Senegal) were trained to diagnose malaria using RDT, provide prompt treatment with artemether-lumefantrine for uncomplicated malaria cases and pre-referral rectal artesunate for complicated malaria occurring in children under 10 years.,Four CHWs were randomized to also administer monthly IPTc as single dose of sulphadoxine-pyrimethamine (SP) plus three doses of amodiaquine (AQ) in the malaria transmission season, October and November 2010.,Primary end point was incidence of single episode of malaria attacks over 8 weeks of follow up.,Secondary end points included prevalence of malaria parasitaemia, and prevalence of anaemia at the end of the transmission season.,Primary analysis was by intention to treat.,The study protocol was approved by the Senegalese National Ethical Committee (approval 0027/MSP/DS/CNRS, 18/03/2010).,A total of 1,000 children were enrolled.,The incidence of malaria episodes was 7.1/100 child months at risk [95% CI (3.7-13.7)] in communities with IPTc + HMM compared to 35.6/100 child months at risk [95% CI (26.7-47.4)] in communities with only HMM (aOR = 0.20; 95% CI 0.09-0.41; p = 0.04).,At the end of the transmission season, malaria parasitaemia prevalence was lower in communities with IPTc + HMM (2.05% versus 4.6% p = 0.03).,Adjusted for age groups, sex, Plasmodium falciparum carriage and prevalence of malnutrition, IPTc + HMM showed a significant protective effect against anaemia (aOR = 0.59; 95% CI 0.42-0.82; p = 0.02).,Combining IPTc and HMM can provide significant additional benefit in preventing clinical episodes of malaria as well as anaemia among children in Senegal.

Mass treatment as a means to reducing P. falciparum malaria transmission was used during the first global malaria eradication campaign and is increasingly being considered for current control programmes.,We used a previously developed mathematical transmission model to explore both the short and long-term impact of possible mass treatment strategies in different scenarios of endemic transmission.,Mass treatment is predicted to provide a longer-term benefit in areas with lower malaria transmission, with reduced transmission levels for at least 2 years after mass treatment is ended in a scenario where the baseline slide-prevalence is 5%, compared to less than one year in a scenario with baseline slide-prevalence at 50%.,However, repeated annual mass treatment at 80% coverage could achieve around 25% reduction in infectious bites in moderate-to-high transmission settings if sustained.,Using vector control could reduce transmission to levels at which mass treatment has a longer-term impact.,In a limited number of settings (which have isolated transmission in small populations of 1000-10,000 with low-to-medium levels of baseline transmission) we find that five closely spaced rounds of mass treatment combined with vector control could make at least temporary elimination a feasible goal.,We also estimate the effects of using gametocytocidal treatments such as primaquine and of restricting treatment to parasite-positive individuals.,In conclusion, mass treatment needs to be repeated or combined with other interventions for long-term impact in many endemic settings.,The benefits of mass treatment need to be carefully weighed against the risks of increasing drug selection pressure.

Recent global progress in scaling up malaria control interventions has revived the goal of complete elimination in many countries.,Decreasing transmission intensity generally leads to increasingly patchy spatial patterns of malaria transmission in elimination settings, with control programs having to accurately identify remaining foci in order to efficiently target interventions.,The role of connectivity between different pockets of local transmission is of increasing importance as programs near elimination since humans are able to transfer parasites beyond the limits of mosquito dispersal, thus re-introducing parasites to previously malaria-free regions.,Here, we discuss recent advances in the quantification of spatial epidemiology of malaria, particularly Plasmodium falciparum, in the context of transmission reduction interventions.,Further, we highlight the challenges and promising directions for the development of integrated mapping, modeling, and genomic approaches that leverage disparate datasets to measure both connectivity and transmission.,A more comprehensive understanding of the spatial transmission of malaria can be gained using a combination of parasite genetics and epidemiological modeling and mapping.,However, additional molecular and quantitative methods are necessary to answer these public health-related questions.

With the rapidly increasing abundance and accessibility of genomic data, there is a growing interest in using population genetic approaches to characterize fine-scale dispersal of organisms, providing insight into biological processes across a broad range of fields including ecology, evolution and epidemiology.,For sexually recombining haploid organisms such as the human malaria parasite P. falciparum, however, there have been no systematic assessments of the type of data and methods required to resolve fine scale connectivity.,This analytical gap hinders the use of genomics for understanding local transmission patterns, a crucial goal for policy makers charged with eliminating this important human pathogen.,Here we use data collected from four clinics with a catchment area spanning approximately 120 km of the Thai-Myanmar border to compare the ability of divergence (FST) and relatedness based on identity by descent (IBD) to resolve spatial connectivity between malaria parasites collected from proximal clinics.,We found no relationship between inter-clinic distance and FST, likely due to sampling of highly related parasites within clinics, but a significant decline in IBD-based relatedness with increasing inter-clinic distance.,This association was contingent upon the data set type and size.,We estimated that approximately 147 single-infection whole genome sequenced parasite samples or 222 single-infection parasite samples genotyped at 93 single nucleotide polymorphisms (SNPs) were sufficient to recover a robust spatial trend estimate at this scale.,In summary, surveillance efforts cannot rely on classical measures of genetic divergence to measure P. falciparum transmission on a local scale.,Given adequate sampling, IBD-based relatedness provides a useful alternative, and robust trends can be obtained from parasite samples genotyped at approximately 100 SNPs.

Preventing relapses of Plasmodium vivax malaria through a radical cure depends on use of the 8-aminoquinoline primaquine, which is associated with safety and compliance issues.,For future malaria eradication strategies, new, safer radical curative compounds that efficiently kill dormant liver stages (hypnozoites) will be essential.,A new compound with potential radical cure activity was identified using a low-throughput assay of in vitro-cultured hypnozoite forms of Plasmodium cynomolgi (an excellent and accessible model for Plasmodium vivax).,In this assay, primary rhesus hepatocytes are infected with P. cynomolgi sporozoites, and exoerythrocytic development is monitored in the presence of compounds.,Liver stage cultures are fixed after 6 days and stained with anti-Hsp70 antibodies, and the relative proportions of small (hypnozoite) and large (schizont) forms relative to the untreated controls are determined.,This assay was used to screen a series of 18 known antimalarials and 14 new non-8-aminoquinolines (preselected for blood and/or liver stage activity) in three-point 10-fold dilutions (0.1, 1, and 10 μM final concentrations).,A novel compound, designated KAI407 showed an activity profile similar to that of primaquine (PQ), efficiently killing the earliest stages of the parasites that become either primary hepatic schizonts or hypnozoites (50% inhibitory concentration [IC50] for hypnozoites, KAI407, 0.69 μM, and PQ, 0.84 μM; for developing liver stages, KAI407, 0.64 μM, and PQ, 0.37 μM).,When given as causal prophylaxis, a single oral dose of 100 mg/kg of body weight prevented blood stage parasitemia in mice.,From these results, we conclude that KAI407 may represent a new compound class for P. vivax malaria prophylaxis and potentially a radical cure.

Over the past decade, there has been a transformation in the portfolio of medicines to combat malaria.,New fixed-dose artemisinin combination therapy is available, with four different types having received approval from Stringent Regulatory Authorities or the World Health Organization (WHO).,However, there is still scope for improvement.,The Malaria Eradication Research agenda identified several gaps in the current portfolio.,Simpler regimens, such as a single-dose cure are needed, compared with the current three-day treatment.,In addition, new medicines that prevent transmission and also relapse are needed, but with better safety profiles than current medicines.,There is also a big opportunity for new medicines to prevent reinfection and to provide chemoprotection.,This study reviews the global portfolio of new medicines in development against malaria, as of the summer of 2012.,Cell-based phenotypic screening, and ‘fast followers’ of clinically validated classes, mean that there are now many new classes of molecules starting in clinical development, especially for the blood stages of malaria.,There remain significant gaps for medicines blocking transmission, preventing relapse, and long-duration molecules for chemoprotection.,The nascent pipeline of new medicines is significantly stronger than five years ago.,However, there are still risks ahead in clinical development and sustainable funding of clinical studies is vital if this early promise is going to be delivered.

No vaccine has yet proven effective against the blood-stages of Plasmodium falciparum, which cause the symptoms and severe manifestations of malaria.,We recently found that PfRH5, a P. falciparum-specific protein expressed in merozoites, is efficiently targeted by broadly-neutralizing, vaccine-induced antibodies.,Here we show that antibodies against PfRH5 efficiently inhibit the in vitro growth of short-term-adapted parasite isolates from Cambodia, and that the EC50 values of antigen-specific antibodies against PfRH5 are lower than those against PfAMA1.,Since antibody responses elicited by multiple antigens are speculated to improve the efficacy of blood-stage vaccines, we conducted detailed assessments of parasite growth inhibition by antibodies against PfRH5 in combination with antibodies against seven other merozoite antigens.,We found that antibodies against PfRH5 act synergistically with antibodies against certain other merozoite antigens, most notably with antibodies against other erythrocyte-binding antigens such as PfRH4, to inhibit the growth of a homologous P. falciparum clone.,A combination of antibodies against PfRH4 and basigin, the erythrocyte receptor for PfRH5, also potently inhibited parasite growth.,This methodology provides the first quantitative evidence that polyclonal vaccine-induced antibodies can act synergistically against P. falciparum antigens and should help to guide the rational development of future multi-antigen vaccines.

Acquired antibodies are important in human immunity to malaria, but key targets remain largely unknown.,Plasmodium falciparum reticulocyte-binding-homologue-4 (PfRh4) is important for invasion of human erythrocytes and may therefore be a target of protective immunity.,IgG and IgG subclass-specific responses against different regions of PfRh4 were determined in a longitudinal cohort of 206 children in Papua New Guinea (PNG).,Human PfRh4 antibodies were tested for functional invasion-inhibitory activity, and expression of PfRh4 by P. falciparum isolates and sequence polymorphisms were determined.,Antibodies to PfRh4 were acquired by children exposed to P. falciparum malaria, were predominantly comprised of IgG1 and IgG3 subclasses, and were associated with increasing age and active parasitemia.,High levels of antibodies, particularly IgG3, were strongly predictive of protection against clinical malaria and high-density parasitemia.,Human affinity-purified antibodies to the binding region of PfRh4 effectively inhibited erythrocyte invasion by P. falciparum merozoites and antibody levels in protected children were at functionally-active concentrations.,Although expression of PfRh4 can vary, PfRh4 protein was expressed by most isolates derived from the cohort and showed limited sequence polymorphism.,Evidence suggests that PfRh4 is a target of antibodies that contribute to protective immunity to malaria by inhibiting erythrocyte invasion and preventing high density parasitemia.,These findings advance our understanding of the targets and mechanisms of human immunity and evaluating the potential of PfRh4 as a component of candidate malaria vaccines.

Preventive chemotherapy campaigns with praziquantel and albendazole are being implemented in Angola, as a high priority public health intervention.,However, there are no published data regarding adverse events associated with these medications.,In this context, we analysed adverse events due to co-administration of praziquantel and albendazole in endemic areas of schistosomiasis and soil-transmitted helminths in Bengo, Angola.,In the context of a targeted drug administration, between December 2012 and September 2013, we conducted two surveys after co-administrating single oral doses of praziquantel and albendazole tablets to children 2 to 15 years of age.,About 24 hours after each treatment, participants answered a questionnaire about adverse events.,At baseline, 605 children (55.0% male; mean age: 9.7 years) were treated; 460 were interviewed and 257 (55.9%) reported at least one adverse event, 62.3% (160/257) of children being infected with schistosoma haematobium.,After six months of treatment, among 339 children surveyed, 184 (54.3%) reported adverse events, with 49.5% (91/184) of infected children.,Adverse events were most common in preschool-aged children, with no significant difference between genders.,The most frequent adverse events in the two surveys were abdominal pain (18.5%, 25.7%), headache (20.9%, 23.0%) and dizziness (15.7%, 19.8%).,Children aged 12 to 15 years (adjusted OR = 0.40, p = 0.040) and those with mixed infection (adjusted OR = 0.04, p = 0.011) had lower odds of adverse events.,After the second treatment, those with heavy infection (adjusted OR = 2.72, p = 0.018) and aged 9-11 years (adjusted OR = 2.01, p = 0.049) had significantly fewer adverse events.,About 2.0% of children experienced severe adverse events.,This study adds evidence that preventive chemotherapy for schistosomiasis and soil-transmitted helminths control is safe, but cases of adverse events are expected.,Standardized methodologies to discriminate drug-related adverse events from the clinical manifestations of the infections are needed.

In 2012 the WHO formally recognised that infants and preschool children are at significant risk of schistosomiasis and qualify for treatment with praziquantel (PZQ).,Targeted surveys determining both the performance and safety of this drug are now needed in endemic areas.,We have formally assessed parasitological cure and putative side-effects in a prospective cohort of Schistosoma mansoni-infected children (aged 5 months-7 years old) in lakeshore settings of Uganda.,From a total of 369 children found to be egg-patent for intestinal schistosomiasis, 305 were followed-up three to four weeks after PZQ treatment and infection status re-assessed.,Separately, a previously tested side-effect questionnaire was employed before and 24 hours after PZQ treatment to assess incidence and amelioration of symptoms in young children and their mothers.,While the overall observed parasitological cure was 56.4%, a significant difference was found between a sub-set of children who had a history of multiple PZQ treatments (between one and four in an 18 month period), where cure rate was 41.7%, and those who had never received treatment (cure rate was 77·6%).,PZQ proved to be safe, with only mild reported side effects which cleared within a month after treatment.,Prevalence of reported symptoms was significantly lower in children than in mothers, and fewer side-effects were reported upon subsequent rounds of PZQ treatment.,Our findings show that PZQ treatment of young children resulted in satisfactory cure rates, and marked reduction in egg-output, with only mild and transient reported side-effects.,However, the cure rate is clearly lower in younger children and those with history of previous treatment.,Cure rate, but not egg reduction rate, was also lower in children with heavier pre-intervention infection intensity.,With chemotherapy now recommended as a long-term strategy for disease control in young children, research into optimising the periodicity of targeted treatment strategies is now crucial.

Leishmaniasis is listed as one of the eight neglected tropical diseases by the World Health Organization and the number of cases in endemic areas has seen a sharp rise in the past decade.,More alarmingly, reports have shown that leishmaniasis is spreading to non-endemic areas of the world due to co-infection with HIV.,In Sri Lanka, leishmaniasis is considered as a notifiable disease from 2008 and has seen a rising trend of incidence since then.,This is the first study describing the burden, seasonal variation and spatial distribution of leishmaniasis in Sri Lanka since the disease has been included as a notifiable disease.,Data on health statistics from 2009 to 2016 were obtained from published databases maintained by the Epidemiology Unit of the Ministry of Health in Sri Lanka.,Climatic data for Sri Lanka were obtained from the Department of Meteorology and the populations in administrative districts were obtained from the Department of Census and Statistics, Sri Lanka.,Descriptive spatiotemporal analysis, correlation between leishmaniasis incidence and climatic variables were analyzed using SPSS statistical software.,The total number of people reported with leishmaniasis during the study period was 8487.,Cutaneous leishmaniasis is the prominent form in Sri Lanka while few visceral and muco-cutaneous cases were reported.,Although leishmaniasis patients were identified from all 25 districts in the island, almost 90% of the total caseload was reported from Anuradhapura, Hambantota, Polonnaruwa, Kurunegala and Matara districts.,The highest number of patients was reported from the Anuradhapura district and the highest incidence per 100,000 persons was reported from the Hambantota district.,The disease has a seasonal trend, a peak of leishmaniasis occur in July to September in the north-central region and in October to December in the southern region.,Maximum temperature, humidity and wind speed are significantly associated climatic variables with leishmaniasis in endemic regions.,Leishmaniasis is an emerging public health problem in north-central and southern Sri Lanka.,Public awareness programs for the prevention and control of the disease in endemic regions are essential to reduce the incidence of leishmaniasis.

As part of a World Health Organization-led effort to update the empirical evidence base for the leishmaniases, national experts provided leishmaniasis case data for the last 5 years and information regarding treatment and control in their respective countries and a comprehensive literature review was conducted covering publications on leishmaniasis in 98 countries and three territories (see ‘Leishmaniasis Country Profiles Text S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20, S21, S22, S23, S24, S25, S26, S27, S28, S29, S30, S31, S32, S33, S34, S35, S36, S37, S38, S39, S40, S41, S42, S43, S44, S45, S46, S47, S48, S49, S50, S51, S52, S53, S54, S55, S56, S57, S58, S59, S60, S61, S62, S63, S64, S65, S66, S67, S68, S69, S70, S71, S72, S73, S74, S75, S76, S77, S78, S79, S80, S81, S82, S83, S84, S85, S86, S87, S88, S89, S90, S91, S92, S93, S94, S95, S96, S97, S98, S99, S100, S101’).,Additional information was collated during meetings conducted at WHO regional level between 2007 and 2011.,Two questionnaires regarding epidemiology and drug access were completed by experts and national program managers.,Visceral and cutaneous leishmaniasis incidence ranges were estimated by country and epidemiological region based on reported incidence, underreporting rates if available, and the judgment of national and international experts.,Based on these estimates, approximately 0.2 to 0.4 cases and 0.7 to 1.2 million VL and CL cases, respectively, occur each year.,More than 90% of global VL cases occur in six countries: India, Bangladesh, Sudan, South Sudan, Ethiopia and Brazil.,Cutaneous leishmaniasis is more widely distributed, with about one-third of cases occurring in each of three epidemiological regions, the Americas, the Mediterranean basin, and western Asia from the Middle East to Central Asia.,The ten countries with the highest estimated case counts, Afghanistan, Algeria, Colombia, Brazil, Iran, Syria, Ethiopia, North Sudan, Costa Rica and Peru, together account for 70 to 75% of global estimated CL incidence.,Mortality data were extremely sparse and generally represent hospital-based deaths only.,Using an overall case-fatality rate of 10%, we reach a tentative estimate of 20,000 to 40,000 leishmaniasis deaths per year.,Although the information is very poor in a number of countries, this is the first in-depth exercise to better estimate the real impact of leishmaniasis.,These data should help to define control strategies and reinforce leishmaniasis advocacy.

The increase in multidrug resistant Plasmodium falciparum infections threatens the malaria elimination goals in countries within the Greater Mekong Sub-region.,A multi-pronged approach assuring access to basic malaria control measures, including insecticide-treated bed nets and early diagnosis and treatment was followed by mass drug administrations (MDA) in southern Savannakhet Province, Laos.,The main objective of this study was to evaluate the effectiveness and safety of mass drug administrations as well as their effects on the dynamic of asymptomatic P. falciparum infections in 4 malaria endemic villages.,Two villages were randomized to early MDA consisting of 3 rounds of a 3-day course of dihydroartemisinin-piperaquine with a single low dose of primaquine.,In the other 2 villages MDA was deferred by 1 year.,A total of 1036 residents were enrolled in early MDA villages and 883 in control villages (deferred-MDA).,Tri-monthly parasitaemia surveys using uPCR were conducted for a year in the 4 villages.,Eighty-four percent (872/1036) of the residents participated in the MDAs, of whom 90% (781/872) completed 3 rounds of MDA (9 doses).,In intervention villages, the prevalence of asymptomatic P. falciparum infections decreased by 85% after MDA from 4.8% (95% CI 3.4-6.4) at baseline (month 0 or M0) to 0.7% (95% CI 0.3-1.6) at month 12.,In control villages there was a decrease of 33% in P. falciparum prevalence between M0: 17.5% (95% CI 15.9-20.3) and M12: 11.6% (95% CI 9.3-14.2).,In bivariate and multivariate analyses P. falciparum infections were significantly reduced with early MDA (adjusted incidence rate ratios (AIRR): 0.08, CI 0.01-0.091) and completion of 3 MDA rounds (AIRR: 0.06; CI 0.01-0.66).,A quarter of participants (226/872) reported adverse events of which 99% were mild.,The study found a significant reduction in P. falciparum prevalence and incidence following MDA.,MDA was safe, well tolerated, feasible, and achieved high population coverage and adherence.,MDAs must be integrated in multi-pronged approaches such as vector control and preventive measures with a focus on specific risk groups such as mobile, migrant population and forest goers for a sustained period to eliminate the remaining parasite reservoirs.,Trial registration ClinicalTrials.gov Identifier: NCT01872702

Mass drug administrations (MDAs) are part of the World Health Organization’s Plasmodium falciparum elimination strategy for the Greater Mekong Subregion (GMS).,In Cambodia, a 2015-2017 clinical trial evaluated the effectiveness of MDA.,This article explores factors that influence the feasibility and acceptability of MDA, including seasonal timing, financial incentives and the delivery model.,Quantitative data were collected through structured questionnaires from the heads of 163 households.,Qualitative data were collected through 25 semi-structured interviews and 5 focus group discussions with villagers and local health staff.,Calendars of village activities were created and meteorological and malaria treatment records were collected.,MDA delivered house-to-house or at a central point, with or without compensation, were equally acceptable and did not affect coverage.,People who knew about the rationale for the MDA, asymptomatic infections and transmission were more likely to participate.,In western Cambodia, MDA delivered house-to-house by volunteers at the end of the dry season may be most practicable but requires the subsequent treatment of in-migrants to prevent reintroduction of infections.,For MDA targeted at individual villages or village clusters it is important to understand local preferences for community mobilisation, delivery and timing, as several models of MDA are feasible.

Molecular epidemiology leverages genetic information to study the risk factors that affect the frequency and distribution of malaria cases.,This article describes molecular epidemiologic investigations currently being carried out by the International Centers of Excellence for Malaria Research (ICEMR) network in a variety of malaria-endemic settings.,First, we discuss various novel approaches to understand malaria incidence and gametocytemia, focusing on Plasmodium falciparum and Plasmodium vivax.,Second, we describe and compare different parasite genotyping methods commonly used in malaria epidemiology and population genetics.,Finally, we discuss potential applications of molecular epidemiological tools and methods toward malaria control and elimination efforts.

The importance of Plasmodium vivax in malaria elimination is increasingly being recognized, yet little is known about its population size and population genetic structure in the South Pacific, an area that is the focus of intensified malaria control.,We have genotyped 13 microsatellite markers in 295 P. vivax isolates from four geographically distinct sites in Papua New Guinea (PNG) and one site from Solomon Islands, representing different transmission intensities.,Diversity was very high with expected heterozygosity values ranging from 0.62 to 0.98 for the different markers.,Effective population size was high (12′872 to 19′533 per site).,In PNG population structuring was limited with moderate levels of genetic differentiation.,F ST values (adjusted for high diversity of markers) were 0.14-0.15.,Slightly higher levels were observed between PNG populations and Solomon Islands (F ST = 0.16).,Low levels of population structure despite geographical barriers to transmission are in sharp contrast to results from regions of low P. vivax endemicity.,Prior to intensification of malaria control programs in the study area, parasite diversity and effective population size remained high.

Antimalarial drugs are key tools for the control and elimination of malaria.,Recent decreases in the global malaria burden are likely due, in part, to the deployment of artemisinin-based combination therapies.,Therefore, the emergence and potential spread of artemisinin-resistant parasites in southeast Asia and changes in sensitivities to artemisinin partner drugs have raised concerns.,In recognition of this urgent threat, the International Centers of Excellence for Malaria Research (ICEMRs) are closely monitoring antimalarial drug efficacy and studying the mechanisms underlying drug resistance.,At multiple sentinel sites of the global ICEMR network, research activities include clinical studies to track the efficacies of antimalarial drugs, ex vivo/in vitro assays to measure drug susceptibilities of parasite isolates, and characterization of resistance-mediating parasite polymorphisms.,Taken together, these efforts offer an increasingly comprehensive assessment of the efficacies of antimalarial therapies, and enable us to predict the emergence of drug resistance and to guide local antimalarial drug policies.,Here we briefly review worldwide antimalarial drug resistance concerns, summarize research activities of the ICEMRs related to drug resistance, and assess the global impacts of the ICEMR programs.

There is a critical need for developing new malaria diagnostic tools that are sensitive, cost effective and capable of performing large scale diagnosis.,The real-time PCR methods are particularly robust for large scale screening and they can be used in malaria control and elimination programs.,We have designed novel self-quenching photo-induced electron transfer (PET) fluorogenic primers for the detection of P. falciparum and the Plasmodium genus by real-time PCR.,A total of 119 samples consisting of different malaria species and mixed infections were used to test the utility of the novel PET-PCR primers in the diagnosis of clinical samples.,The sensitivity and specificity were calculated using a nested PCR as the gold standard and the novel primer sets demonstrated 100% sensitivity and specificity.,The limits of detection for P. falciparum was shown to be 3.2 parasites/µl using both Plasmodium genus and P. falciparum-specific primers and 5.8 parasites/µl for P. ovale, 3.5 parasites/µl for P. malariae and 5 parasites/µl for P. vivax using the genus specific primer set.,Moreover, the reaction can be duplexed to detect both Plasmodium spp. and P. falciparum in a single reaction.,The PET-PCR assay does not require internal probes or intercalating dyes which makes it convenient to use and less expensive than other real-time PCR diagnostic formats.,Further validation of this technique in the field will help to assess its utility for large scale screening in malaria control and elimination programs.

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.

This article reports the changing pattern of US President’s Malaria Initiative-funded IRS in sub-Saharan Africa between 2008 and 2015.,IRS coverage in sub-Saharan Africa increased from <2 % of the at-risk population in 2005, to 11 % or 78 million people in 2010, mainly as a result of increased funding from PMI.,The scaling up of IRS coverage in sub-Saharan Africa has been successful in several epidemiological settings and contributed to reduced malaria transmission rates.,However, the spread and intensification of pyrethroid resistance in malaria vectors led many control programmes to spray alternative insecticides.,Between 2009 and 2013, pyrethroid spraying decreased from 87 % (13/15) of PMI-funded countries conducting IRS to 44 % (7/16), while bendiocarb use increased from 7 % (1/15) to 56 % (9/16).,Long-lasting pirimiphos-methyl CS received WHOPES recommendation in 2013 and was scheduled to be sprayed in 85 % (11/13) of PMI-funded countries conducting IRS in 2015.,The gradual replacement of relatively inexpensive pyrethroids, firstly with bendiocarb (carbamate) and subsequently with pirimiphos methyl CS (organophosphate), has contributed to the downscaling of most PMI-funded IRS programmes.,Overall, there was a 53 % decrease in the number of structures sprayed between years of peak coverage and 2015, down from 9.04 million to 4.26 million structures.,Sizeable reductions in the number of structures sprayed were reported in Madagascar (56 %, 576,320-254,986), Senegal (64 %, 306,916-111,201), Tanzania (68 %, 1,224,095-389,714) and Zambia (63 %, 1,300,000-482,077), while in Angola, Liberia and Malawi PMI-funded spraying was suspended.,The most commonly cited reason was increased cost of pesticides, as vector resistance necessitated switching from pyrethroids to organophosphates.,There are worrying preliminary reports of malaria resurgence following IRS withdrawal in parts of Benin, Tanzania and Uganda.,The increase in malaria cases following the end of the Global Malaria Eradication Programme in 1969 highlights the fragility of such gains when control efforts are weakened.,At present there are several countries reliant on organophosphates and carbamates for IRS, and increasing incipient resistance is a serious threat that could result in IRS no longer being viable.,A portfolio of new cost-effective insecticides with different modes of action is urgently needed.

Interferon gamma (IFNγ) is the major proinflammatory cytokine conferring resistance to the intracellular vacuolar pathogen Toxoplasma gondii by inducing the destruction of the parasitophorous vacuole (PV).,We previously identified TRIM21 as an IFNγ-driven E3 ubiquitin ligase mediating the deposition of ubiquitin around pathogen inclusions.,Here, we show that TRIM21 knockout mice were highly susceptible to Toxoplasma infection, exhibiting decreased levels of serum inflammatory cytokines and higher parasite burden in the peritoneum and brain.,We demonstrate that IFNγ drives recruitment of TRIM21 to GBP1-positive Toxoplasma vacuoles, leading to Lys63-linked ubiquitination of the vacuole and restriction of parasite early replication without interfering with vacuolar disruption.,As seen in vivo, TRIM21 impacted the secretion of inflammatory cytokines.,This study identifies TRIM21 as a previously unknown modulator of Toxoplasma gondii resistance in vivo thereby extending host innate immune recognition of eukaryotic pathogens to include E3 ubiquitin ligases.

Toxoplasma gondii is the most common protozoan parasitic infection in man.,Gamma interferon (IFNγ) activates haematopoietic and non-haematopoietic cells to kill the parasite and mediate host resistance.,IFNγ-driven host resistance pathways and parasitic virulence factors are well described in mice, but a detailed understanding of pathways that kill Toxoplasma in human cells is lacking.,Here we show, that contrary to the widely held belief that the Toxoplasma vacuole is non-fusogenic, in an immune-stimulated environment, the vacuole of type II Toxoplasma in human cells is able to fuse with the host endo-lysosomal machinery leading to parasite death by acidification.,Similar to murine cells, we find that type II, but not type I Toxoplasma vacuoles are targeted by K63-linked ubiquitin in an IFNγ-dependent manner in non-haematopoetic primary-like human endothelial cells.,Host defence proteins p62 and NDP52 are subsequently recruited to the type II vacuole in distinct, overlapping microdomains with a loss of IFNγ-dependent restriction in p62 knocked down cells.,Autophagy proteins Atg16L1, GABARAP and LC3B are recruited to <10% of parasite vacuoles and show no parasite strain preference, which is consistent with inhibition and enhancement of autophagy showing no effect on parasite replication.,We demonstrate that this differs from HeLa human epithelial cells, where type II Toxoplasma are restricted by non-canonical autophagy leading to growth stunting that is independent of lysosomal acidification.,In contrast to mouse cells, human vacuoles do not break.,In HUVEC, the ubiquitinated vacuoles are targeted for destruction in acidified LAMP1-positive endo-lysosomal compartments.,Consequently, parasite death can be prevented by inhibiting host ubiquitination and endosomal acidification.,Thus, K63-linked ubiquitin recognition leading to vacuolar endo-lysosomal fusion and acidification is an important, novel virulence-driven Toxoplasma human host defence pathway.

Maternal malaria is associated with serious adverse pregnancy outcomes.,One recommended means of preventing malaria during pregnancy is intermittent preventive therapy (IPTp) with sulfadoxine/pyrimethamine (SP).,We sought to identify determinants of preventive use of SP during pregnancy among recently pregnant women in Uganda.,Additionally, we characterized the timing of and indications for the administration of SP at antenatal care (ANC) visits and missed opportunities for SP administration.,Utilizing a population-based random sample, we interviewed 500 women living in Jinja, Uganda who had been pregnant in the past year.,Thirty-eight percent (192/500) of women received SP for the treatment of malaria and were excluded from the analysis of IPTp-SP.,Of the remaining women, 275 (89.3%) reported at least two ANC visits after the first trimester and had an opportunity to receive IPTp-SP according to the Ugandan guidelines, but only 86 (31.3%) of these women received a full two-dose course of IPTp.,The remaining 189 (68.7%) women missed one or more doses of IPTp-SP.,Among the 168 women that were offered IPTp, 164 (97.6%) of them took the dose of SP.,Use of IPTp in Uganda was found to be far below target levels.,Our results suggest that women will take SP for IPTp if it is offered during an ANC visit.,Missed opportunities to administer IPTp-SP during ANC were common in our study, suggesting provider-level improvements are needed.

The Tanzanian government recommends women who attend antenatal care (ANC) clinics to accept receiving intermittent preventive treatment against malaria during pregnancy (IPTp) and vouchers for insecticide-treated nets (ITNs) at subsidized prices.,Little emphasis has been paid to investigate the ability of pregnant women to access and effectively utilize these services.,To describe the experience and perceptions of pregnant women about costs and cost barriers for accessing ANC services with emphasis on IPTp in rural Tanzania.,Qualitative data were collected in the districts of Mufindi in Iringa Region and Mkuranga in Coast Region through 1) focus group discussions (FGDs) with pregnant women and mothers to infants and 2) exit-interviews with pregnant women identified at ANC clinics.,Data were analyzed manually using qualitative content analysis methodology.,FGD participants and interview respondents identified the following key limiting factors for women's use of ANC services: 1) costs in terms of money and time associated with accessing ANC clinics, 2) the presence of more or less official user-fees for some services within the ANC package, and 3) service providers' application of fines, penalties and blame when failing to adhere to service schedules.,Interestingly, the time associated with travelling long distances to ANC clinics and ITN retailers and with waiting for services at clinic-level was a major factor of discouragement in the health seeking behaviour of pregnant women because it seriously affected their domestic responsibilities.,A variety of resource-related factors were shown to affect the health seeking behaviour of pregnant women in rural Tanzania.,Thus, accessibility to ANC services was hampered by direct and indirect costs, travel distances and waiting time.,Strengthening of user-fee exemption practices and bringing services closer to the users, for example by promoting community-directed control of selected public health services, including IPTp, are urgently needed measures for increasing equity in health services in Tanzania.

Plasmodium sporozoites are transmitted from infected mosquitoes to mammals, and must navigate the host skin and vasculature to infect the liver.,This journey requires distinct proteomes.,Here, we report the dynamic transcriptomes and proteomes of both oocyst sporozoites and salivary gland sporozoites in both rodent-infectious Plasmodium yoelii parasites and human-infectious Plasmodium falciparum parasites.,The data robustly define mRNAs and proteins that are upregulated in oocyst sporozoites (UOS) or upregulated in infectious sporozoites (UIS) within the salivary glands, including many that are essential for sporozoite functions in the vector and host.,Moreover, we find that malaria parasites use two overlapping, extensive, and independent programs of translational repression across sporozoite maturation to temporally regulate protein expression.,Together with gene-specific validation experiments, these data indicate that two waves of translational repression are implemented and relieved at different times during sporozoite maturation, migration and infection, thus promoting their successful development and vector-to-host transition.,Here, the authors report transcriptomes and proteomes of oocyst sporozoite and salivary gland sporozoite stages in rodent-infectious Plasmodium yoelii parasites and human infectious Plasmodium falciparum parasites and define two waves of translational repression during sporozoite maturation.

Bioluminescence imaging is widely used for cell-based assays and animal imaging studies, both in biomedical research and drug development.,Its main advantages include its high-throughput applicability, affordability, high sensitivity, operational simplicity, and quantitative outputs.,In malaria research, bioluminescence has been used for drug discovery in vivo and in vitro, exploring host-pathogen interactions, and studying multiple aspects of Plasmodium biology.,While the number of fluorescent proteins available for imaging has undergone a great expansion over the last two decades, enabling simultaneous visualization of multiple molecular and cellular events, expansion of available luciferases has lagged behind.,The most widely used bioluminescent probe in malaria research is the Photinus pyralis firefly luciferase, followed by the more recently introduced Click-beetle and Renilla luciferases.,Ultra-sensitive imaging of Plasmodium at low parasite densities has not been previously achieved.,With the purpose of overcoming these challenges, a Plasmodium berghei line expressing the novel ultra-bright luciferase enzyme NanoLuc, called PbNLuc has been generated, and is presented in this work.,NanoLuc shows at least 150 times brighter signal than firefly luciferase in vitro, allowing single parasite detection in mosquito, liver, and sexual and asexual blood stages.,As a proof-of-concept, the PbNLuc parasites were used to image parasite development in the mosquito, liver and blood stages of infection, and to specifically explore parasite liver stage egress, and pre-patency period in vivo.,PbNLuc is a suitable parasite line for sensitive imaging of the entire Plasmodium life cycle.,Its sensitivity makes it a promising line to be used as a reference for drug candidate testing, as well as the characterization of mutant parasites to explore the function of parasite proteins, host-parasite interactions, and the better understanding of Plasmodium biology.,Since the substrate requirements of NanoLuc are different from those of firefly luciferase, dual bioluminescence imaging for the simultaneous characterization of two lines, or two separate biological processes, is possible, as demonstrated in this work.

Parasitic nematodes (roundworms) of livestock have major economic impact globally.,In spite of the diseases caused by these nematodes and some advances in the design of new therapeutic agents (anthelmintics) and attempts to develop vaccines against some of them, there has been limited progress in the establishment of practical diagnostic techniques.,The specific and sensitive diagnosis of gastrointestinal nematode infections of livestock underpins effective disease control, which is highly relevant now that anthelmintic resistance (AR) is a major problem.,Traditional diagnostic techniques have major constraints, in terms of sensitivity and specificity.,The purpose of this article is to provide a brief background on gastrointestinal nematodes (Strongylida) of livestock and their control; to summarize conventional methods used for the diagnosis and discuss their constraints; to review key molecular-diagnostic methods and recent progress in the development of advanced amplification-based and sequencing technologies, and their implications for epidemiological investigations and the control of parasitic diseases.

Resistance to gastrointestinal nematodes has previously been shown to be a moderately heritable trait in some breeds of sheep, but the mechanisms of resistance are not well understood.,Selection for resistance currently relies upon faecal egg counts (FEC), blood packed cell volumes and FAMACHA visual indicator scores of anaemia.,Identifying genomic markers associated with disease resistance would potentially improve the selection process and provide a more reliable means of classifying and understanding the biology behind resistant and susceptible sheep.,A GWAS was conducted to identify possible genetic loci associated with resistance to Haemonchus contortus in Katahdin sheep.,Forty animals were selected from the top and bottom 10% of estimated breeding values for FEC from a total pool of 641 sires and ram lambs.,Samples were genotyped using Applied Biosystems™ Axiom™ Ovine Genotyping Array (50K) consisting of 51 572 SNPs.,Following quality control, 46 268 SNPs were included in subsequent analyses.,Analyses were conducted using a linear regression model in plink v1.90 and a single‐locus mixed model in snp and variation suite.,Genome‐wide significance was determined by a Bonferroni correction for multiple testing.,Using linear regression, loci on chromosomes 2, 3, 16, 23 and 24 were significantly associated at the genome level with FEC estimated breeding values, and we identified a region on chromosome 2 that was significant using both statistical analyses.,We suggest a potential role for the gene DIS3L2 for gastrointestinal nematode resistance in Katahdin sheep, although further research is needed to validate these findings.

Plasmodium knowlesi was identified as the fifth major malaria parasite in humans.,It presents severe clinical symptoms and leads to mortality as a result of hyperparasitemia in a short period of time.,This study aimed to improve the current understanding of P. knowlesi and identify potential biomarkers for knowlesi malaria.,In the present study, we have employed two-dimensional gel electrophoresis-coupled immunoblotting techniques and mass spectrometry to identify novel circulating markers in sera from P. knowlesi-infected patients.,Specifically, we have compared serum protein profiles from P. knowlesi-infected patients against those of healthy or P. vivax-infected individuals.,We identified several immunoreactive proteins in malarial-infected subjects, including alpha-2-HS glycoprotein (AHSG), serotransferrin (TF), complement C3c (C3), hemopexin (HPX), zinc-2-alpha glycoprotein (ZAG1), apolipoprotein A1 (Apo-A1), haptoglobin (HAP), and alpha-1-B-glycoprotein (A1BG).,However, only TF and HPX displayed enhanced antigenicity and specificity, suggesting that they might represent valid markers for detecting P. knowlesi infection.,Additionally, six P. knowlesi-specific antigens were identified (K15, K16, K28, K29, K30, and K38).,Moreover, although HAP antigenicity was observed during P. vivax infection, it was undetectable in P. knowlesi-infected subjects.,We have demonstrated the application of immunoproteomics approach to identify potential candidate biomarkers for knowlesi malaria infection.

Severe malaria is a leading cause of childhood mortality in Africa.,However, at presentation, it is difficult to predict which children with severe malaria are at greatest risk of death.,Dysregulated host inflammatory responses and endothelial activation play central roles in severe malaria pathogenesis.,We hypothesized that biomarkers of these processes would accurately predict outcome among children with severe malaria.,Plasma was obtained from children with uncomplicated malaria (n = 53), cerebral malaria (n = 44) and severe malarial anemia (n = 59) at time of presentation to hospital in Kampala, Uganda.,Levels of angiopoietin-2, von Willebrand Factor (vWF), vWF propeptide, soluble P-selectin, soluble intercellular adhesion molecule-1 (ICAM-1), soluble endoglin, soluble FMS-like tyrosine kinase-1 (Flt-1), soluble Tie-2, C-reactive protein, procalcitonin, 10 kDa interferon gamma-induced protein (IP-10), and soluble triggering receptor expressed on myeloid cells-1 (TREM-1) were determined by ELISA.,Receiver operating characteristic (ROC) curve analysis was used to assess predictive accuracy of individual biomarkers.,Six biomarkers (angiopoietin-2, soluble ICAM-1, soluble Flt-1, procalcitonin, IP-10, soluble TREM-1) discriminated well between children who survived severe malaria infection and those who subsequently died (area under ROC curve>0.7).,Combinational approaches were applied in an attempt to improve accuracy.,A biomarker score was developed based on dichotomization and summation of the six biomarkers, resulting in 95.7% (95% CI: 78.1-99.9) sensitivity and 88.8% (79.7-94.7) specificity for predicting death.,Similar predictive accuracy was achieved with models comprised of 3 biomarkers.,Classification tree analysis generated a 3-marker model with 100% sensitivity and 92.5% specificity (cross-validated misclassification rate: 15.4%, standard error 4.9%).,We identified novel host biomarkers of pediatric severe and fatal malaria (soluble TREM-1 and soluble Flt-1) and generated simple biomarker combinations that accurately predicted death in an African pediatric population.,While requiring validation in further studies, these results suggest the utility of combinatorial biomarker strategies as prognostic tests for severe malaria.

Malaria incidence in Myanmar has significantly reduced over recent years, however, completeness and timeliness of incidence data remain a challenge.,The first ever nationwide malaria infection and seroprevalence survey was conducted in Myanmar in 2015 to better understand malaria epidemiology and highlight gaps in Annual Parasite Index (API) data.,The survey was a cross-sectional two-stage stratified cluster-randomised household survey conducted from July-October 2015.,Blood samples were collected from household members for ultra-sensitive PCR and serology testing for P. falciparum and P. vivax.,Data was gathered on demography and a priori risk factors of participants.,Data was analysed nationally and within each of four domains defined by API data.,Prevalence and seroprevalence of malaria were 0.74% and 16.01% nationwide, respectively.,Prevalent infection was primarily asymptomatic P. vivax, while P. falciparum was predominant in serology.,There was large heterogeneity between villages and by domain.,At the township level, API showed moderate correlation with P. falciparum seroprevalence.,Risk factors for infection included socioeconomic status, domain, and household ownership of nets.,Three K13 P. falciparum mutants were found in highly prevalent villages.,There results highlight high heterogeneity of both P. falciparum and P. vivax transmission between villages, accentuated by a large hidden reservoir of asymptomatic P. vivax infection not captured by incidence data, and representing challenges for malaria elimination.,Village-level surveillance and stratification to guide interventions to suit local context and targeting of transmission foci with evidence of drug resistance would aid elimination efforts.

A substantial proportion of Plasmodium species infections are asymptomatic with densities too low to be detectable with standard diagnostic techniques.,The importance of such asymptomatic plasmodium infections in malaria transmission is probably related to their duration and density.,To explore the duration of asymptomatic plasmodium infections and changes in parasite densities over time, a cohort of participants who were infected with Plasmodium parasites was observed over a 2-year follow-up period.,In this open cohort study, inhabitants of four villages in Vietnam were invited to participate in baseline and subsequent 3-monthly surveys up to 24 months, which included the collection of venous blood samples.,Samples were batch-screened using ultra-sensitive (u)PCR (lower limit of detection of 22 parasites per mL).,Participants found to be infected by uPCR during any of these surveys were invited to join a prospective cohort and provide monthly blood samples.,We estimated the persistence of Plasmodium falciparum and Plasmodium vivax infections and changes in parasite densities over a study period of 24 months.,Between Dec 1, 2013, and Jan 8, 2016, 356 villagers participated in between one and 22 surveys.,These study participants underwent 4248 uPCR evaluations (11·9 tests per participant). 1874 (32%) of 4248 uPCR tests indicated a plasmodium infection; 679 (36%) of 1874 tests were P falciparum monoinfections, 507 (27%) were P vivax monoinfections, 463 (25%) were co-infections with P falciparum and P vivax, and 225 (12%) were indeterminate species of Plasmodium.,The median duration of P falciparum infection was 2 months (IQR 1-3); after accounting for censoring, participants had a 20% chance of having parasitaemia for 4 months or longer.,The median duration of P vivax infection was 6 months (3-9), and participants had a 59% chance of having parasitaemia for 4 months or longer.,The parasite densities of persistent infections oscillated; following ultralow-density infections, high-density infections developed frequently.,Persistent largely asymptomatic P vivax and P falciparum infections are common in this area of low seasonal malaria transmission.,Infections with low-density parasitaemias can develop into much higher density infections at a later time, which are likely to sustain malaria endemicity.,The Wellcome Trust, Bill & Melinda Gates Foundation.

Despite the extensive ownership and use of insecticide-treated nets (ITNs) over the last decade, the effective lifespan of these nets, especially their physical integrity, under true operational conditions is not well-understood.,Usefulness of nets declines primarily due to physical damage or loss of insecticidal activity.,A community based cross-sectional survey was used to determine the physical condition and to identify predictors of poor physical condition for bed nets owned by individuals from communities in Kwale County, coastal Kenya.,A proportionate hole index (pHI) was used as a standard measure, and the cut-offs for an ‘effective net’ (offer substantial protection against mosquito bites) and ‘ineffective nets’ (offer little or no protection against mosquito bites) were determined (pHI ≤88 (about ≤500 cm2 of holes surface area) and pHI of >88 (≥500 cm2 of holes surface area), respectively).,The vast majority (78%) of the surveyed nets had some holes.,The median pHI was 92 (range: 1-2,980).,Overall, half of the nets were categorized as ‘effective nets’ or ‘serviceable nets’.,Physical deterioration of nets was associated with higher use and washing frequency.,Young children and older children were found to use ineffective bed nets significantly more often than infants, while the physical integrity of nets owned by pregnant women was similar to those owned by infants.,Estuarine environment inhabitants owned nets with the worst physical condition, while nets owned by the coastal slope inhabitants were in fairly good physical condition.,The results suggest that bed nets are optimally utilized when they are new and physically intact.,Thereafter, bed net utilization decreases gradually with increasing physical deterioration, with most net owners withdrawing physically damaged nets from routine use.,This withdrawal commonly happens following 1.5 years of use, making bed net use the most important predictor of physical integrity.,On average, the nets were washed twice within six months prior to the survey.,Washing frequency was significantly influenced by the bed net colour and bed net age.,Lack of knowledge on reasons for net retreatment and the retreatment procedure was evident, while net repair was minimal and did not seem to improve the physical condition of the nets.,The “catch-up” bed net distribution strategies are sufficient for ensuring adequate ownership and utilization of ‘effective nets’ in the targeted groups, but bi-annual mass distribution is necessary to provide similar ownership and utilization for the other groups not targeted by “catch-up” strategies.,Monitoring and maintenance strategies that will deliver locally appropriate education messages on net washing and repair will enhance the effectiveness of malaria control programmes, and further research to assess ineffective nets need is needed.

Ownership of insecticidal mosquito nets has dramatically increased in Ethiopia since 2006, but the proportion of persons with access to such nets who use them has declined.,It is important to understand individual level net use factors in the context of the home to modify programmes so as to maximize net use.,Generalized linear latent and mixed models (GLLAMM) were used to investigate net use using individual level data from people living in net-owning households from two surveys in Ethiopia: baseline 2006 included 12,678 individuals from 2,468 households and a sub-sample of the Malaria Indicator Survey (MIS) in 2007 included 14,663 individuals from 3,353 households.,Individual factors (age, sex, pregnancy); net factors (condition, age, net density); household factors (number of rooms [2006] or sleeping spaces [2007], IRS, women's knowledge and school attendance [2007 only], wealth, altitude); and cluster level factors (rural or urban) were investigated in univariate and multi-variable models for each survey.,In 2006, increased net use was associated with: age 25-49 years (adjusted (a) OR = 1.4, 95% confidence interval (CI) 1.2-1.7) compared to children U5; female gender (aOR = 1.4; 95% CI 1.2-1.5); fewer nets with holes (Ptrend = 0.002); and increasing net density (Ptrend < 0.001).,Reduced net use was associated with: age 5-24 years (aOR = 0.2; 95% CI 0.2-0.3).,In 2007, increased net use was associated with: female gender (aOR = 1.3; 95% CI 1.1-1.6); fewer nets with holes (aOR [all nets in HH good] = 1.6; 95% CI 1.2-2.1); increasing net density (Ptrend < 0.001); increased women's malaria knowledge (Ptrend < 0.001); and urban clusters (aOR = 2.5; 95% CI 1.5-4.1).,Reduced net use was associated with: age 5-24 years (aOR = 0.3; 95% CI 0.2-0.4); number of sleeping spaces (aOR [per additional space] = 0.6, 95% CI 0.5-0.7); more old nets (aOR [all nets in HH older than 12 months] = 0.5; 95% CI 0.3-0.7); and increasing household altitude (Ptrend < 0.001).,In both surveys, net use was more likely by women, if nets had fewer holes and were at higher net per person density within households.,School-age children and young adults were much less likely to use a net.,Increasing availability of nets within households (i.e. increasing net density), and improving net condition while focusing on education and promotion of net use, especially in school-age children and young adults in rural areas, are crucial areas for intervention to ensure maximum net use and consequent reduction of malaria transmission.

Blood samples collected in epidemiological and clinical investigations and then stored, often at room temperature, as blood spots dried on a filter paper have become one of the most popular source of material for further molecular analyses of malaria parasites.,The dried blood spots are often archived so that they can be used for further retrospective investigations of parasite prevalence, or as new genetic markers come to the fore.,However, the suitability of the template obtained from dried blood spots that have been stored for long periods for DNA amplification is not known.,DNA from 267 archived blood spots collected over a period of 12 years from persons with microscopically confirmed Plasmodium falciparum infection was purified by one of two methods, Chelex and Qiagen columns.,These templates were subjected to highly sensitive nested PCR amplification targeting three parasite loci that differ in length and/or copy number.,When a 1.6 kb fragment of the parasites’ small subunit ribosomal RNA was targeted (primary amplification), the efficiency of P. falciparum detection decreased in samples archived for more than six years, reaching very low levels for those stored for more than 10 years.,Positive amplification was generally obtained more often with Qiagen-extracted templates.,P. falciparum could be detected in 32 of the 40 negative Qiagen-extracted templates when a microsatellite of about 180 bp was targeted.,The remaining eight samples gave a positive amplification when a small region of 238 bp of the higher copy number (20 to 200) mitochondrial genome was targeted.,The average length of DNA fragments that can be recovered from dried blood spots decreases with storage time.,Recovery of the DNA is somewhat improved, especially in older samples, by the use of a commercial DNA purification column, but targets larger than 1.5 kb are unlikely to be present 10 years after the initial blood collection, when the average length of the DNA fragments present is likely to be around a few hundred bp.,In conclusion, the utility of archived dried blood spots for molecular analyses decreases with storage time.

Malaria microscopy and rapid diagnostic tests are insensitive for very low-density parasitaemia.,This insensitivity may lead to missed asymptomatic sub-microscopic parasitaemia, a potential reservoir for infection.,Similarly, mixed infections and interactions between Plasmodium species may be missed.,The objectives were first to develop a rapid and sensitive PCR-based diagnostic method to detect low parasitaemia and mixed infections, and then to investigate the epidemiological importance of sub-microscopic and mixed infections in Rattanakiri Province, Cambodia.,A new malaria diagnostic method, using restriction fragment length polymorphism analysis of the cytochrome b genes of the four human Plasmodium species and denaturing high performance liquid chromatography, has been developed.,The results of this RFLP-dHPLC method have been compared to 1) traditional nested PCR amplification of the 18S rRNA gene, 2) sequencing of the amplified fragments of the cytochrome b gene and 3) microscopy.,Blood spots on filter paper and Giemsa-stained blood thick smears collected in 2001 from 1,356 inhabitants of eight villages of Rattanakiri Province have been analysed by the RFLP-dHPLC method and microscopy to assess the prevalence of sub-microscopic and mixed infections.,The sensitivity and specificity of the new RFLP-dHPLC was similar to that of the other molecular methods.,The RFLP-dHPLC method was more sensitive and specific than microscopy, particularly for detecting low-level parasitaemia and mixed infections.,In Rattanakiri Province, the prevalences of Plasmodium falciparum and Plasmodium vivax were approximately two-fold and three-fold higher, respectively, by RFLP-dHPLC (59% and 15%, respectively) than by microscopy (28% and 5%, respectively).,In addition, Plasmodium ovale and Plasmodium malariae were never detected by microscopy, while they were detected by RFLP-dHPLC, in 11.2% and 1.3% of the blood samples, respectively.,Moreover, the proportion of mixed infections detected by RFLP-dHPLC was higher (23%) than with microscopy (8%).,The rapid and sensitive molecular diagnosis method developed here could be considered for mass screening and ACT treatment of inhabitants of low-endemicity areas of Southeast Asia.

Despite decades of research on cerebral malaria (CM) there is still a paucity of knowledge about what actual causes CM and why certain people develop it.,Although sequestration of P. falciparum infected red blood cells has been linked to pathology, it is still not clear if this is directly or solely responsible for this clinical syndrome.,Recent data have suggested that a combination of parasite variant types, mainly defined by the variant surface antigen, P. falciparum erythrocyte membrane protein 1 (PfEMP1), its receptors, coagulation and host endothelial cell activation (or inflammation) are equally important.,This makes CM a multi-factorial disease and a challenge to unravel its causes to decrease its detrimental impact.

Severe malaria has been attributed partly to the sequestration of Plasmodium falciparum-infected erythrocytes (IEs) in the microvasculature of vital host organs.,Identification of P. falciparum cytoadherence phenotypes that are associated with severe malaria may lead to the development of novel strategies against life-threatening malaria.,Forty-six P. falciparum isolates from Mozambican children under 5 years of age with severe malaria (cases) were examined and compared to 46 isolates from sex and age matched Mozambican children with uncomplicated malaria (controls).,Cytoadherence properties such as platelet-mediated clumping, rosetting and adhesion to purified receptors (CD36, ICAM1 and gC1qR), were compared between these matched pairs by non-parametric tests.,The most common clinical presentation associated with severe malaria was prostration.,Compared to matched controls, prevalence of platelet-mediated clumping was higher in cases (P = .019), in children presenting with prostration (P = .049) and in children with severe anaemia (P = .025).,Prevalence of rosetting and gC1qR adhesion were also higher in isolates from cases with severe anemia and multiple seizures, respectively (P = .045 in both cases), than in controls.,These data indicate a role for platelet-mediated clumping, rosetting and adhesion to gC1qR in the pathogenesis of severe malaria.,Inhibition of these cytoadherence phenotypes may reduce the occurrence or improve the prognosis of severe malaria outcomes.

The radical cure of Plasmodium vivax and P. ovale requires treatment with primaquine or tafenoquine to clear dormant liver stages.,Either drug can induce haemolysis in individuals with glucose-6-phosphate dehydrogenase (G6PD) deficiency, necessitating screening.,The reference diagnostic method for G6PD activity is ultraviolet (UV) spectrophotometry; however, a universal G6PD activity threshold above which these drugs can be safely administered is not yet defined.,Our study aimed to quantify assay-based variation in G6PD spectrophotometry and to explore the diagnostic implications of applying a universal threshold.,Individual-level data were pooled from studies that used G6PD spectrophotometry.,Studies were identified via PubMed search (25 April 2018) and unpublished contributions from contacted authors (PROSPERO: CRD42019121414).,Studies were excluded if they assessed only individuals with known haematological conditions, were family studies, or had insufficient details.,Studies of malaria patients were included but analysed separately.,Included studies were assessed for risk of bias using an adapted form of the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool.,Repeatability and intra- and interlaboratory variability in G6PD activity measurements were compared between studies and pooled across the dataset.,A universal threshold for G6PD deficiency was derived, and its diagnostic performance was compared to site-specific thresholds.,Study participants (n = 15,811) were aged between 0 and 86 years, and 44.4% (7,083) were women.,Median (range) activity of G6PD normal (G6PDn) control samples was 10.0 U/g Hb (6.3-14.0) for the Trinity assay and 8.3 U/g Hb (6.8-15.6) for the Randox assay.,G6PD activity distributions varied significantly between studies.,For the 13 studies that used the Trinity assay, the adjusted male median (AMM; a standardised metric of 100% G6PD activity) varied from 5.7 to 12.6 U/g Hb (p < 0.001).,Assay precision varied between laboratories, as assessed by variance in control measurements (from 0.1 to 1.5 U/g Hb; p < 0.001) and study-wise mean coefficient of variation (CV) of replicate measures (from 1.6% to 14.9%; p < 0.001).,A universal threshold of 100% G6PD activity was defined as 9.4 U/g Hb, yielding diagnostic thresholds of 6.6 U/g Hb (70% activity) and 2.8 U/g Hb (30% activity).,These thresholds diagnosed individuals with less than 30% G6PD activity with study-wise sensitivity from 89% (95% CI: 81%-94%) to 100% (95% CI: 96%-100%) and specificity from 96% (95% CI: 89%-99%) to 100% (100%-100%).,However, when considering intermediate deficiency (<70% G6PD activity), sensitivity fell to a minimum of 64% (95% CI: 52%-75%) and specificity to 35% (95% CI: 24%-46%).,Our ability to identify underlying factors associated with study-level heterogeneity was limited by the lack of availability of covariate data and diverse study contexts and methodologies.,Our findings indicate that there is substantial variation in G6PD measurements by spectrophotometry between sites.,This is likely due to variability in laboratory methods, with possible contribution of unmeasured population factors.,While an assay-specific, universal quantitative threshold offers robust diagnosis at the 30% level, inter-study variability impedes performance of universal thresholds at the 70% level.,Caution is advised in comparing findings based on absolute G6PD activity measurements across studies.,Novel handheld quantitative G6PD diagnostics may allow greater standardisation in the future.,Daniel Pfeffer and coauthors report on the assessment of glucose-6-phosphate dehydrogenase activity, which is required for safe use of some malaria treatments.

Primaquine is the only drug available to prevent relapse in vivax malaria.,The main adverse effect of primaquine is erythrocyte age and dose-dependent acute haemolytic anaemia in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd).,As testing for G6PDd is often unavailable, this limits the use of primaquine for radical cure.,A compartmental model of the dynamics of red blood cell production and destruction was designed to characterise primaquine-induced haemolysis using a holistic Bayesian analysis of all published data and was used to predict a safer alternative to the currently recommended once weekly 0.75 mg/kg regimen for G6PDd.,The model suggests that a step-wise increase in daily administered primaquine dose would be relatively safe in G6PDd.,If this is confirmed, then were this regimen to be recommended for radical cure patients would not require testing for G6PDd in areas where G6PDd Viangchan or milder variants are prevalent.,DOI:http://dx.doi.org/10.7554/eLife.23061.001,Malaria is the most important parasitic disease that affects humans.,Over half of the malaria cases in Asia and South America are caused by a species of malaria parasite called Plasmodium vivax (known as vivax malaria).,This form of malaria results in repeated illness because dormant parasites in the liver wake at intervals to infect the blood.,The only available drug that can stop these relapses is a drug called primaquine, which was developed seventy years ago.,Unfortunately, primaquine causes dangerous side effects in certain individuals who are deficient in an enzyme called G6PD, which helps defend red blood cells against stresses.,Primaquine damages these cells so that they burst, leading to anaemia.,This is a major problem because G6PD deficiency is common in regions where malaria is present: in some areas up to 30% of the population may be G6PD deficient.,Since G6PD testing is not widely available, doctors often avoid prescribing primaquine to treat malaria, which results in more cases of disease relapse.,Failing to prevent vivax relapses causes extensive illness and hinders efforts to eliminate malaria.,Is there a way to give this drug to patients that would be safer for people with G6PD deficiency?,Primaquine destroys older rather than younger red blood cells.,Watson et al. used mathematical modelling to see whether it is possible to develop a primaquine treatment strategy that would allow a gradual destruction of older red blood cells in individuals with G6PD deficiency, which would be safer.,The mathematical model incorporates data from previous studies in malaria patients and healthy volunteers with G6PD deficiency and combines this with knowledge of how red blood cells are produced and destroyed.,Watson et al. predicted that giving primaquine over 20 days in a steadily increasing dose was safer than current recommendations.,Mathematical models are simplifications of real world processes.,The only way to test these findings properly will be to run a clinical trial that gives healthy volunteers who are G6PD deficient a course of primaquine treatment with a steadily increasing dose.,DOI:http://dx.doi.org/10.7554/eLife.23061.002

Self-report is the most common and feasible method for assessing patient adherence to medication, but can be prone to recall bias and social desirability bias.,Most studies assessing adherence to artemisinin-based combination therapies (ACTs) have relied on self-report.,In this study, we use a novel customised electronic monitoring device-termed smart blister packs-to examine the validity of self-reported adherence to artemether-lumefantrine (AL) in southern Tanzania.,Smart blister packs were designed to look identical to locally available AL blister packs and to record the date and time each tablet was removed from packaging.,Patients obtaining AL at randomly selected health facilities and drug stores were followed up at home three days later and interviewed about each dose of AL taken.,Blister packs were requested for pill count and extraction of smart blister pack data.,Data on adherence from both self-report verified by pill count and smart blister packs were available for 696 of 1,204 patients.,There was no difference between methods in the proportion of patients assessed to have completed treatment (64% and 67%, respectively).,However, the percentage taking the correct number of pills for each dose at the correct times (timely completion) was higher by self-report than smart blister packs (37% vs. 24%; p<0.0001).,By smart blister packs, 64% of patients completing treatment did not take the correct number of pills per dose or did not take each dose at the correct time interval.,Smart blister packs resulted in lower estimates of timely completion of AL and may be less prone to recall and social desirability bias.,They may be useful when data on patterns of adherence are desirable to evaluate treatment outcomes.,Improved methods of collecting self-reported data are needed to minimise bias and maximise comparability between studies.

Current Uganda National Malaria treatment guidelines recommend parasitological confirmation either by microscopy or rapid diagnostic test (RDT) before treatment with artemether-lumefantrine (AL).,However, the cost-effectiveness of these strategies has not been assessed at rural operational primary care centres.,Three health centres (HCs) were randomized to three diagnostic arms (microscopy, RDT and presumptive diagnosis) in a district of low and another of high malaria transmission intensities in Uganda.,Some 22,052 patients presenting with fever at outpatients departments were enrolled from March 2010 to February 2011.,Of these, a random sample of 1,627 was selected to measure additional socio-economic characteristics.,Costing was performed following the standard step-down cost allocation and the ingredients approach.,Effectiveness was measured as the number and proportion of patients correctly diagnosed and treated.,Incremental Cost-Effectiveness Ratios (ICERs) were estimated from the societal perspective (http://Clinicaltrials.gov, NCT00565071).,Overall RDT was most cost-effective with lowest ICER US$5.0 compared to microscopy US$9.61 per case correctly diagnosed and treated.,In the high transmission setting, ICER was US$4.38 for RDT and US$12.98 for microscopy.,The corresponding ICERs in the low transmission setting were US$5.85 and US$7.63 respectively.,The difference in ICERs between RDT and microscopy was greater in the high transmission area (US$8.9) than in low transmission setting (US$1.78).,At a willingness to pay of US$2.8, RDT remained cost effective up to a threshold value of the cost of treatment of US$4.7.,RDT was cost effective in both low and high transmission settings.,With a global campaign to reduce the costs of AL and RDT, the Malaria Control Programme and stakeholders need a strategy for malaria diagnosis because as the cost of AL decreases, presumptive treatment is likely to become more attractive.

The complex network of interactions occurring between gastrointestinal (GI) and extra-intestinal (EI) parasitic helminths of humans and animals and the resident gut microbial flora is attracting increasing attention from biomedical researchers, because of the likely implications for the pathophysiology of helminth infection and disease.,Nevertheless, the vast heterogeneity of study designs and microbial community profiling strategies, and of bioinformatic and biostatistical approaches for analyses of metagenomic sequence datasets hinder the identification of bacterial targets for follow-up experimental investigations of helminth-microbiota cross-talk.,Furthermore, comparative analyses of published datasets are made difficult by the unavailability of a unique repository for metagenomic sequence data and associated metadata linked to studies aimed to explore potential changes in the composition of the vertebrate gut microbiota in response to GI and/or EI helminth infections.,Here, we undertake a meta-analysis of available metagenomic sequence data linked to published studies on helminth-microbiota cross-talk in humans and veterinary species using a single bioinformatic pipeline, and introduce the 'MICrobiome HELminth INteractions database' (MICHELINdb), an online resource for mining of published sequence datasets, and corresponding metadata, generated in these investigations.,By increasing data accessibility, we aim to provide the scientific community with a platform to identify gut microbial populations with potential roles in the pathophysiology of helminth disease and parasite-mediated suppression of host inflammatory responses, and facilitate the design of experiments aimed to disentangle the cause(s) and effect(s) of helminth-microbiota relationships.,Video abstract.,Video abstract.

•A Bayesian latent class meta-analysis of diagnostic tests for soil-transmitted helminths was performed.,•Overall sensitivity of evaluated diagnostic tests was low.,•Test performance was strongly influenced by intensity of infection.,•FLOTAC method sensitivity was highest overall and in both intensity groups.,•The performance of the Kato-Katz method in high intensity settings was acceptable.,A Bayesian latent class meta-analysis of diagnostic tests for soil-transmitted helminths was performed.,Overall sensitivity of evaluated diagnostic tests was low.,Test performance was strongly influenced by intensity of infection.,FLOTAC method sensitivity was highest overall and in both intensity groups.,The performance of the Kato-Katz method in high intensity settings was acceptable.,Reliable, sensitive and practical diagnostic tests are an essential tool in disease control programmes for mapping, impact evaluation and surveillance.,To provide a robust global assessment of the relative performance of available diagnostic tools for the detection of soil-transmitted helminths, we conducted a meta-analysis comparing the sensitivities and the quantitative performance of the most commonly used copro-microscopic diagnostic methods for soil-transmitted helminths, namely Kato-Katz, direct microscopy, formol-ether concentration, McMaster, FLOTAC and Mini-FLOTAC.,In the absence of a perfect reference standard, we employed a Bayesian latent class analysis to estimate the true, unobserved sensitivity of compared diagnostic tests for each of the soil-transmitted helminth species Ascaris lumbricoides, Trichuris trichiura and the hookworms.,To investigate the influence of varying transmission settings we subsequently stratified the analysis by intensity of infection.,Overall, sensitivity estimates varied between the different methods, ranging from 42.8% for direct microscopy to 92.7% for FLOTAC.,The widely used double slide Kato-Katz method had a sensitivity of 74-95% for the three soil-transmitted helminth species at high infection intensity, however sensitivity dropped to 53-80% in low intensity settings, being lowest for hookworm and A. lumbricoides.,The highest sensitivity, overall and in both intensity groups, was observed for the FLOTAC method, whereas the sensitivity of the Mini-FLOTAC method was comparable with the Kato-Katz method.,FLOTAC average egg count estimates were significantly lower compared with Kato-Katz, while the compared McMaster counts varied.,In conclusion, we demonstrate that the Kato-Katz and Mini-FLOTAC methods had comparable sensitivities.,We further show that test sensitivity of the Kato-Katz method is reduced in low transmission settings.

Malaria is one of the three major global health threats.,Drug development for malaria, especially for its most dangerous form caused by Plasmodium falciparum, remains an urgent task due to the emerging drug-resistant parasites.,Exploration of novel antimalarial drug targets identified a trifunctional enzyme, malate quinone oxidoreductase (MQO), located in the mitochondrial inner membrane of P. falciparum (PfMQO).,PfMQO is involved in the pathways of mitochondrial electron transport chain, tricarboxylic acid cycle, and fumarate cycle.,Recent studies have shown that MQO is essential for P. falciparum survival in asexual stage and for the development of experiment cerebral malaria in the murine parasite P. berghei, providing genetic validation of MQO as a drug target.,However, chemical validation of MQO, as a target, remains unexplored.,In this study, we used active recombinant protein rPfMQO overexpressed in bacterial membrane fractions to screen a total of 400 compounds from the Pathogen Box, released by Medicines for Malaria Venture.,The screening identified seven hit compounds targeting rPfMQO with an IC50 of under 5 μM.,We tested the activity of hit compounds against the growth of 3D7 wildtype strain of P. falciparum, among which four compounds showed an IC50 from low to sub-micromolar concentrations, suggesting that PfMQO is indeed a potential antimalarial drug target.

The battle against malaria has been substantially impeded by the recurrence of drug resistance in Plasmodium falciparum, the deadliest human malaria parasite.,To counter the problem, novel antimalarial drugs are urgently needed, especially those that target unique pathways of the parasite, since they are less likely to have side effects.,The mitochondrial type II NADH dehydrogenase (NDH2) of P. falciparum, PfNDH2 (PF3D7_0915000), has been considered a good prospective antimalarial drug target for over a decade, since malaria parasites lack the conventional multi-subunit NADH dehydrogenase, or Complex I, present in the mammalian mitochondrial electron transport chain (mtETC).,Instead, Plasmodium parasites contain a single subunit NDH2, which lacks proton pumping activity and is absent in humans.,A significant amount of effort has been expended to develop PfNDH2 specific inhibitors, yet the essentiality of PfNDH2 has not been convincingly verified.,Herein, we knocked out PfNDH2 in P. falciparum via a CRISPR/Cas9 mediated approach.,Deletion of PfNDH2 does not alter the parasite’s susceptibility to multiple mtETC inhibitors, including atovaquone and ELQ-300.,We also show that the antimalarial activity of the fungal NDH2 inhibitor HDQ and its new derivative CK-2-68 is due to inhibition of the parasite cytochrome bc1 complex rather than PfNDH2.,These compounds directly inhibit the ubiquinol-cytochrome c reductase activity of the malarial bc1 complex.,Our results suggest that PfNDH2 is not likely a good antimalarial drug target.

A system for controlled sexual conversion of malaria parasites enables the characterization of early sexual stages.,Malaria transmission requires that some asexual parasites convert into sexual forms termed gametocytes.,The initial stages of sexual development, including sexually committed schizonts and sexual rings, remain poorly characterized, mainly because they are morphologically identical to their asexual counterparts and only a small subset of parasites undergo sexual development.,Here, we describe a system for controlled sexual conversion in the human malaria parasite Plasmodium falciparum, based on conditional expression of the PfAP2-G transcription factor.,Using this system, ~90 percent of the parasites converted into sexual forms upon induction, enabling the characterization of committed and early sexual stages without further purification.,We characterized sexually committed schizonts and sexual rings at the transcriptomic and phenotypic levels, which revealed down-regulation of genes involved in solute transport upon sexual commitment, among other findings.,The new inducible lines will facilitate the study of early sexual stages at additional levels, including multiomic characterization and drug susceptibility assays.

Plasmodium spp. parasites are the causative agents of malaria in humans and animals, and they are exceptionally diverse in their morphology and life cycles.,They grow and develop in a wide range of host environments, both within blood-feeding mosquitoes, their definitive hosts, and in vertebrates, which are intermediate hosts.,This diversity is testament to their exceptional adaptability and poses a major challenge for developing effective strategies to reduce the disease burden and transmission.,Following one asexual amplification cycle in the liver, parasites reach high burdens by rounds of asexual replication within red blood cells.,A few of these blood-stage parasites make a developmental switch into the sexual stage (or gametocyte), which is essential for transmission.,The bone marrow, in particular the haematopoietic niche (in rodents, also the spleen), is a major site of parasite growth and sexual development.,This Review focuses on our current understanding of blood-stage parasite development and vascular and tissue sequestration, which is responsible for disease symptoms and complications, and when involving the bone marrow, provides a niche for asexual replication and gametocyte development.,Understanding these processes provides an opportunity for novel therapies and interventions.,Plasmodium falciparum and other malaria parasites have complex life cycles, inhabiting different host cells and tissues during their multistage development.,In this Review, Marti and colleagues discuss blood-stage parasite development and the newly discovered reservoir in the haematopoietic niche.