bluuebunny/crossref_metadata_2025 huggingface dataset:
FIELD COMPARISON OF IMMUNODIAGNOSTIC AND PARASITOLOGICAL TECHNIQUES FOR THE DETECTION OF SCHISTOSOMIASIS JAPONICA IN THE PEOPLE’S REPUBLIC OF CHINA
Authors: ZHOU YI-BIAO , YANG MEI-XIA , WANG QI-ZHI , ZHAO GEN-MING , WEI JIAN-GUO , PENG WEN-XIANG , JIANG QING-WU
Published: September 2018

A total of 1,811 individuals from two villages located in the areas of China endemic for Schistosoma japonicum were analyzed by the Kato-Katz parasitologic examination, indirect hemagglutination assay (IHA), and enzyme-linked immunosorbent assay (ELISA). Statistical analysis of the results showed the κ indices ranged from 0.106 to 0.234 between IHA and the stool examination and ranged from 0.037 to 0.134 between ELISA and the fecal examination. The sensitivity value of the IHA was 83.7% in Village A and 92.3% in Village B; the specificity value of the IHA was 55.8% in Village A and 67.3% in Village B. The sensitivity value of the ELISA was 88.4% in Village A and 96.2% in Village B; the specificity value of the ELISA was 38.4% in both Village A and Village B. A search for a good diagnostic test that can be applied in field situations in China should be given high priority.
EPIDEMIOLOGY OF TOXOCARIASIS IN A STEPPE ENVIRONMENT: THE PATAGONIA STUDY
Authors: FILLAUX JUDITH , SANTILLAN GRACIELA , MAGNAVAL JEAN-FRANÇOIS , JENSEN OSCAR , LARRIEU EDMUNDO , SOBRINO-BECARIA CLAUDIA DANIELA
Published: September 2018

To investigate the epidemiology of human toxocariasis in a steppe environment, a field survey was carried out in three provinces of Argentina’s Patagonia (Chubut, Neuquen, and Rio Negro) among 114 rural subjects residing in estancias (cattle- or sheep-breeding ranches). Overall seroprevalence was 31.6%, and the contamination rate of soil by Toxocara eggs was 35.1%. Bivariate and multivariate analyses were performed for various exposure variables and also for the De Martonne aridity–humidity index. Multivariate analysis revealed that the seroprevalence rate was found to be inversely correlated with age but was positively linked to De Martonne index. These findings suggest that the harsh climatic conditions existing in Argentina’s Patagonia would inhibit embryonation of eggs in the soil, thus lowering the transmission of human toxocariasis.
PHARMACOKINETICS OF AZITHROMYCIN AND THE COMBINATION OF IVERMECTIN AND ALBENDAZOLE WHEN ADMINISTERED ALONE AND CONCURRENTLY IN HEALTHY VOLUNTEERS
Authors: AMSDEN GUY W. , GREGORY THOMAS B. , MICHALAK CHERYL A. , GLUE PAUL , KNIRSCH CHARLES A.
Published: September 2018

Azithromycin is a critical component of an integrated disease elimination program against trachoma. This study was conducted to evaluate whether azithromycin has a pharmacokinetic interaction with the combination of ivermectin and albendazole. Eighteen healthy volunteers were administered single doses of azithromycin, ivermectin/albendazole, and the combination of the three agents in random, crossover fashion. To assess the presence of interactions, test (combination) and reference (single dose) data were compared using an estimation approach. Compared with reference phases, the geometric mean values for the combination arm’s azithromycin AUC0–t and Cmax were increased approximately 13% and 20%, respectively, albendazole AUC0–t decreased by approximately 3% and Cmax increased approximately 3%, and ivermectin AUC0–t and Cmax were increased 31% and 27%, respectively. Albendazole sulfoxide AUC0–t and Cmax were decreased approximately 16% and 14%, respectively. All treatments were well tolerated. The interactions for azithromycin and albendazole were minimal although the increase in ivermectin exposure requires further study.
EMERGENCE OF SHIGA TOXIN 1 GENES WITHIN SHIGELLA DYSENTERIAE TYPE 4 ISOLATES FROM TRAVELERS RETURNING FROM THE ISLAND OF HISPAÑOLA
Authors: GUPTA SUNDEEP K. , STROCKBINE NANCY , OMONDI MICHAEL , HISE KELLEY , FAIR MARY ANN , MINTZ ERIC
Published: September 2018

Shiga toxins are produced by Shigella dysenteriae type 1 and certain strains of Escherichia coli. Three cases of Shiga toxin–producing S. dysenteriae type 4 were identified among travelers to the island of Hispañola between 2002 and 2005. Clinical and public health practitioners should be aware of this newly identified strain.
SALIVARY GLAND MORPHOLOGY AND VIRUS TRANSMISSION DURING LONG-TERM CYTOPATHOLOGIC WEST NILE VIRUS INFECTION IN CULEX MOSQUITOES
Authors: GIRARD YVETTE A. , SCHNEIDER BRADLEY S. , MCGEE CHARLES E. , WEN JULIE , HAN VIOLET C. , POPOV VSEVOLOD , MASON PETER W. , HIGGS STEPHEN
Published: September 2018

The effect of long-term West Nile virus (WNV) infection on Culex salivary gland morphology and viability was evaluated by transmission electron microscopy during a four week period post-blood feeding. These studies showed that apoptosis and other cytopathologic changes occurred more frequently in WNV-infected mosquitoes compared with uninfected controls. The effect of long-term infection on WNV transmission was evaluated by titering virus in saliva over the same time period. Although the mean titer of WNV in mosquito saliva did not change significantly over time, the percentage of saliva samples containing WNV decreased. Because of the importance of saliva in blood meal acquisition and virus delivery, salivary gland pathology has the potential to affect mosquito feeding behavior and virus transmission. Results from this study add to a growing body of evidence that arbovirus infections in mosquito vectors can be cytopathic, and offer a potential mechanism for virus-induced cell death in mosquitoes.
SEROPREVALENCE OF CHIKUNGUNYA VIRUS INFECTION ON GRANDE COMORE ISLAND, UNION OF THE COMOROS, 2005
Authors: SERGON KIBET , YAHAYA ALI AHMED , BROWN JENNIFER , BEDJA SAID A. , MLINDASSE MOHAMMED , AGATA NAPHTALI , ALLARANGER YOKOUIDE , BALL MAMADOU D. , POWERS ANN M. , OFULA VICTOR , ONYANGO CLAYTON , KONONGOI LIMBASO S. , SANG ROSEMARY , NJENGA M. KARIUKI , BREIMAN ROBERT F.
Published: September 2018

An outbreak of Chikungunya virus (CHIKV) illness associated with high fever combined with prolonged and severe arthralgias occurred on Grande Comore Island from January through May 2005; 5,202 cases were reported. A seroprevalence study was conducted to define the extent of transmission on the island. We conducted a cross-sectional survey using a multistage sampling technique. A total of 481 households were sampled. In each household, one resident was selected randomly for interview and blood collection. We administered questionnaires and tested 331 sera for CHIKV-specific IgM and IgG antibodies by capture enzyme-linked immunosorbent assay. Infection with CHIKV infection (seropositivity) was defined as presence of IgG and/or IgM antibodies to CHIKV. A total of 331 (69%) of 481 survey participants consented to blood collection. Antibodies to CHIKV were detected in 63% of sera; IgM antibodies were found in 60% of specimens and IgG antibodies were detected in 27% of specimens. Extrapolation of the findings to the entire Grande Comore population suggested that nearly 215,000 people were infected with CHIKV during the outbreak. A total of 79% of the seropositive persons were hospitalized or stayed at home in bed for a mean of 6 days (range = 1–30 days); 52% missed work or school for a mean of 7 days (range = 1–40 days). The findings suggest that CHIKV was broadly transmitted during the outbreak with a high attack rate. Although not fatal during this outbreak, CHIKV infection caused significant morbidity and decreased economic productivity.
HIGH-THROUGHPUT IDENTIFICATION OF THE PREDOMINANT MALARIA PARASITE CLONE IN COMPLEX BLOOD STAGE INFECTIONS USING A MULTI-SNP MOLECULAR HAPLOTYPING ASSAY
Authors: COLE-TOBIAN JENNIFER L. , ZIMMERMAN PETER A. , KING CHRISTOPHER L.
Published: September 2018

Individuals living in malaria endemic areas are often infected with multiple parasite clones. Currently used single nucleotide polymorphism (SNP) genotyping methods for malaria parasites are cumbersome; furthermore, few methods currently exist that can rapidly determine the most abundant clone in these complex infections. Here we describe an oligonucleotide ligation assay (OLA) to distinguish SNPs in the Plasmodium vivax Duffy binding protein gene (Pvdbp) at 14 polymorphic residues simultaneously. Allele abundance is determined by the highest mean fluorescent intensity of each allele. Using mixtures of plasmids encoding known haplotypes of the Pvdbp, single clones of P. vivax parasites from infected Aotus monkeys, and well-defined mixed infections from field samples, we were able to identify the predominant Pvdbp genotype with > 93% accuracy when the dominant clone is twice as abundant as a lesser genotype and > 97% of the time if the ratio was 5:1 or greater. Thus, the OLA can accurately, reproducibly, and rapidly determine the predominant parasite haplotype in complex blood stage infections.
LEPTOSPIROSIS IN KAMPHAENG PHET, THAILAND
Authors: MYINT KHIN S. A. , GIBBONS ROBERT V. , MURRAY CLINTON K. , RUNGSIMANPHAIBOON KAMCHAI , SUPORNPUN WITAYA , SITHIPRASASNA RATANA , GRAY MICHAEL R. , PIMGATE CHUSAK , MAMMEN MAMMEN P. , HOSPENTHAL DUANE R.
Published: September 2018

Leptospirosis, which is caused by pathogenic spirochetes of the genus Leptospira, is a zoonotic disease of global importance and an emerging health problem. We studied patients suspected of having leptospirosis in Kamphaeng Phet Province, Thailand. Of 106 patients with suspected leptospirosis evaluated at the provincial hospital, 69 (65%) were confirmed positive (titer ≥ 1:800 or ≥ 4-fold increase in titer) by microscopic agglutination testing. Seventy-seven percent (53) of the cases occurred during the rainy season (June through November). Sera reacted predominantly with Bratislava, Autumnalis, and Icterohaemorrhagiae serovars. The screening Leptospira Dip-S-Ticks test had poor sensitivity (32%) but a specificity of 100% compared with a Leptospira IgM enzyme-linked immunosorbent assay. Leptospirosis was found to be a frequently confirmed cause of morbidity in Kamphaeng Phet Province in those suspected of having the illness.
DETECTION OF SALMONELLA TYPHI BY NESTED POLYMERASE CHAIN REACTION IN BLOOD, URINE, AND STOOL SAMPLES
Authors: HATTA MOCHAMMAD , SMITS HENK L.
Published: September 2018

A nested polymerase chain reaction (PCR) specific for Salmonella enterica serovar Typhi was used for the detection of the pathogen in blood, urine, and stool samples from 131 patients with clinical suspicion of typhoid fever. The sensitivity of blood culture, the PCRs with blood, urine, and feces, and the Widal test were 61.8%, 84.5%, 69.3%, 46.9%, and 39.0%, respectively. The sensitivity of the PCRs with blood (P < 0.001) and urine (P = 0.01) were significantly higher, and the sensitivity of the PCR with feces (P > 0.05) was similar to that of blood culture. Combined, the PCRs on urine and feces showed positive results for 16 (70%) of 23 typhoid patients with negative results with blood culture and PCR with blood. These results show that the PCR with blood is a sensitive method for the diagnosis of typhoid fever, and that the PCRs with urine and feces could be useful complementary tests.
INNATE IMMUNE RESPONSES IN HUMAN DENDRITIC CELLS UPON INFECTION BY CHIMERIC YELLOW-FEVER DENGUE VACCINE SEROTYPES 1–4
Authors: DEAUVIEAU FLORENCE , SANCHEZ VIOLETTE , BALAS CLAIRE , KENNEL AUDREY , DE MONTFORT AYMERIC , LANG JEAN , GUY BRUNO
Published: September 2018

Dengue infection is an important public health issue worldwide. The ChimeriVax™-Dengue (CYD) vaccine uses yellow fever (YF) 17D vaccine as a live vector. Dendritic cells (DCs) play a key role in initiating immune responses and could be an important primary target of dengue infection. We investigated in vitro the consequences of CYD infection of DCs on their activation/maturation and cytokine production. In CYD-infected DCs, we observed an up-regulation of HLA-DR, CD80, CD86, and CD83. Cells exposed to CYD secreted type I interferons, monocyte chemoattractant protein 1 (MCP-1)/CC chemokine ligand 2 (CCL-2), interleukin-6 (IL-6), and low amounts of tumor necrosis factor-α (TNF-α), but no IL-10, IL-12, or IL-1α. Parental dengue viruses induced a similar array of cytokines, but more TNF-α, less IL-6, and less MCP-1/CCL-2 than induced by CYD. Chimeras thus induced DCs maturation and a controlled response accompanied by limited inflammatory cytokine production and consistent expression of anti-viral interferons, in agreement with clinical observations of safety and immunogenicity.
HUMAN METAPNEUMOVIRUS IN CHILDREN WITH INFLUENZA-LIKE ILLNESS IN YUCATAN, MEXICO
Authors: TALAVERA GUADALUPE AYORA , MÉZQUITA NELSON E. DORANTES
Published: September 2018

The present study suggests that human metapneumovirus (hMPV) is an important cause of community acquired respiratory infections in children. We report the detection of hMPV in a pediatric population with influenza-like illness in the subtropical area of Yucatan in Mexico. Our data also shows that hMPV circulates in the community with other respiratory pathogens.
SEASONALITY, BLOOD FEEDING BEHAVIOR, AND TRANSMISSION OF PLASMODIUM FALCIPARUM BY ANOPHELES ARABIENSIS AFTER AN EXTENDED DROUGHT IN SOUTHERN ZAMBIA
Authors: KENT REBEKAH J. , THUMA PHILIP E. , MHARAKURWA SUNGANO , NORRIS DOUGLAS E.
Published: September 2018

Transmission of Plasmodium falciparum is hyperendemic in southern Zambia. However, no data on the entomologic aspects of malaria transmission have been published from Zambia in more than 25 years. We evaluated seasonal malaria transmission by Anopheles arabiensis and An. funestus s.s. and characterized the blood feeding behavior of An. arabiensis in two village areas. Transmission during the 2004–2005 rainy season was nearly zero because of widespread drought. During 2005–2006, the estimated entomologic inoculation rate values were 1.6 and 18.3 infective bites per person per transmission season in each of the two village areas, respectively. Finally, with a human blood index of 0.923, An. arabiensis was substantially more anthropophilic in our study area than comparable samples of indoor-resting An. arabiensis throughout Africa and was the primary vector responsible for transmission of P. falciparum.
OF MAURER’S CLEFTS IN PLASMODIUM FALCIPARUM–INFECTED ERYTHROCYTES
Authors: HAEGGSTRÖM MALIN , VON EULER ANNE , KIRONDE FRED , FERNANDEZ VICTOR , WAHLGREN MATS
Published: September 2018

In 1902 Georg Maurer was the first to publish a detailed description of Giemsa-stained structures in the cytosol of Plasmodium falciparum–infected erythrocytes, today known as Maurer’s clefts. Later when clefts were seen by electron microscopy, the description was modified to also include these, which has caused disagreement over the composition of Maurer’s clefts. For that reason, Maurer’s clefts were characterized during intraerythrocytic development of P. falciparum by simultaneously staining cytosolic structures with antibodies using indirect immunofluorescence assays and with Giemsa. At least three groups of antigens, P. falciparum erythrocyte membrane protein 1 (PfEMP1)/ RIFIN/SURFIN, P. falciparum histidine-rich protein 2 (PfHRP2), and exported proteins 1 and 2 (Exp1 and Exp2), were detected in distinct Giemsa-stained structures in the cytosol of infected erythrocytes, but PfHRP2 and Exp1/Exp2 were not found in clefts by transmission electron microscopy. Therefore, Maurer’s clefts as defined by staining with Giemsa comprise a number of cytoplasmic structures and antigens not included in structures called clefts and seen by electron microscopy.
LOW PREVALENCE OF AN ACUTE PHASE RESPONSE IN ASYMPTOMATIC CHILDREN FROM A MALARIA-ENDEMIC AREA OF PAPUA NEW GUINEA
Authors: IMRIE HEATHER , FOWKES FREYA J. I. , MICHON PASCAL , TAVUL LIVINGSTONE , REEDER JOHN C. , DAY KAREN P.
Published: September 2018

Levels of C-reactive protein (CRP), a classic marker for the acute phase response (APR), were measured in children with asymptomatic malaria infection in the Amele region of Papua New Guinea (PNG). Despite the presence of parasitemia, the prevalence of CRP levels consistent with an APR (CRP > 10 μg/mL) was very low (< 10%). Splenomegaly was significantly associated with increased parasitemia (P < 0.001) and CRP levels (P < 0.001), highlighting the importance of splenomegaly as an indicator of recent high density infection in this population. Multivariate analysis showed that CRP levels were significantly associated with splenomegaly, fever, hemoglobin, and age (P ≤ 0.002). CRP levels also increased with increasing parasitemia (P < 0.001) but remained < 3.5 μg/mL. The low levels of CRP indicate that children in the Amele modulate inflammation associated with malaria.
DYNAMICS OF PASSIVE IMMUNITY TO WEST NILE VIRUS IN DOMESTIC CHICKENS (GALLUS GALLUS DOMESTICUS)
Authors: NEMETH NICOLE M. , BOWEN RICHARD A.
Published: September 2018

Birds are the principle amplifying hosts for West Nile virus (WNV), and understanding the acquisition and decay of passive immunity is important to avian surveillance and diagnostics. We characterized passive transfer of WNV-neutralizing antibody from chicken (Gallus gallus domesticus) hens to eggs and chicks and the protective efficacy and decay of maternally acquired antibody over time. We also characterized age-associated changes in magnitude of viremia and examined the possibility of vertical transmission of WNV. All egg yolks and chicks from seropositive hens were maternal antibody positive. Maternal antibodies were undetectable in most chicks by 28 days post-hatch (PH), but some chicks remained protected as late as 42 days PH. By 56 days PH, chicks from immune hens had viremia profiles similar to control chicks. There were significant age-related differences in WNV-attributed morbidity and viremia levels of unprotected chicks. Vertical transmission of WNV was not detected.
MOSQUITO FEEDING PATTERNS AND NATURAL INFECTION OF VERTEBRATES WITH ROSS RIVER AND BARMAH FOREST VIRUSES IN BRISBANE, AUSTRALIA
Authors: KAY BRIAN H. , BOYD ANN MARIE , RYAN PETER A. , HALL ROY A.
Published: September 2018

Host feeding patterns of mosquitoes were assessed through the identification of 865 blood meals collected from Brisbane during 2000–2001. Under natural conditions, mosquito feeding (including that of Culex annulirostris, Aedes vigilax, and Aedes notoscriptus) was primarily on dogs (37.4%), but also on birds (18.4%), horses (16.8%), brushtail possums (13.3%), humans (11.6%), and cats, flying foxes, and macropods, depending on site. From 1997 to 1999, sera (N = 1706) were collected from dogs, cats, horses, flying foxes, and brushtail possums in the Brisbane area and were analyzed by microneutralization assay for antibodies to Ross River virus (RRV) and Barmah Forest virus (BFV). For RRV, all vertebrate species tested had been naturally infected, and seroprevalence varied from 10.5% to 25.5%, whereas for BFV, rates varied between 0% and 11.3%. Brushtail possums were often infected in the field, with 17.6% and 10.7% of wild individuals having antibodies to RRV and BFV, respectively. Horses and flying foxes also had a relatively high prevalence of antibodies to RRV. This study, therefore, provides data to indicate that brushtail possums play a role in the urban transmission of RRV in Brisbane and that horses, when they occur, also fill the same role.
SEVEN YEARS OF REGIONAL MALARIA CONTROL COLLABORATION—MOZAMBIQUE, SOUTH AFRICA, AND SWAZILAND
Authors: SHARP BRIAN L. , KLEINSCHMIDT IMMO , STREAT ELISABETH , MAHARAJ RAJENDRA , BARNES KAREN I. , DURRHEIM DAVID N. , RIDL FRANCES C. , MORRIS NATASHA , SEOCHARAN ISHEN , KUNENE SIMON , LA GRANGE JACOBUS J. P. , MTHEMBU JOTHAM D. , MAARTENS FRANCOIS , MARTIN CARRIN L. , BARRETO AVERTINO
Published: September 2018

The Lubombo Spatial Development Initiative is a joint development program between the governments of Mozambique, Swaziland, and South Africa, which includes malaria control as a core component of the initiative. Vector control through indoor residual spraying (IRS) was incrementally introduced in southern Mozambique between November 2000 and February 2004. Surveillance to monitor its impact was conducted by annual cross-sectional surveys to assess the prevalence of Plasmodium falciparum infection, entomologic monitoring, and malaria case notification in neighboring South Africa and Swaziland. In southern Mozambique, there was a significant reduction in P. falciparum prevalence after the implementation of IRS, with an overall relative risk of 0.74 for each intervention year (P < 0.001), ranging from 0.66 after the first year to 0.93 after the fifth intervention year. Substantial reductions in notified malaria cases were reported in South Africa and Swaziland over the same period. The success of the program in reducing malaria transmission throughout the target area provides a strong argument for investment in regional malaria control.
CRIMEAN-CONGO HEMORRHAGIC FEVER AMONG HEALTH CARE WORKERS IN IRAN: A SEROPREVALENCE STUDY IN TWO ENDEMIC REGIONS
Authors: MARDANI MASOUD , RAHNAVARDI MOHAMMAD , RAJAEINEJAD MOHSEN , NAINI KOUROSH HOLAKOUI , CHINIKAR SADEGH , POURMALEK FARSHAD , ROSTAMI MOJTABA , SHAHRI MOHAMMAD HASHEMI
Published: September 2018

Crimean-Congo hemorrhagic fever (CCHF) has repeatedly caused nosocomial outbreaks among hospital staff. In the summer of 2003, we studied the seroprevalence of anti-CCHF IgG among health care workers who had come in contact with Crimean-Congo hemorrhagic fever patients from three referral hospitals in endemic regions of Iran. A total of 223 eligible staff were examined. Whereas 5 of 129 (3.87%) exposed health care workers tested positive, none of the 94 in the unexposed group did (P = 0.075). Seropositivity was more frequent among those whose intact skin had come in contact with nonsanguineous body fluids (9.52%) and those who had had percutaneous contacts (7.14%). Health care workers exposed to Crimean-Congo hemorrhagic fever patients, those who live in Systan-Baluchestan province, and older health care workers were more prone to seropositivity. Where introduction of high-risk modes of contact cannot be confined, we propose that health care workers take all the protective measures when handling Crimean-Congo hemorrhagic fever patients, particularly their blood and other body fluids.
ANTIPLASMODIAL INTERACTIONS BETWEEN ARTEMISININ AND TRICLOSAN OR KETOCONAZOLE COMBINATIONS AGAINST BLOOD STAGES OF PLASMODIUM FALCIPARUM IN VITRO
Authors: MISHRA LOKESH C. , BHATTACHARYA AMIT , BHASIN VIRENDRA K.
Published: September 2018

Emergence of drug-resistant Plasmodium falciparum strains to conventional first-line antimalarial drugs has compelled many countries to reorient their drug policies to adopt artemisinin-based combination therapies (ACTs) for treatment of uncomplicated malaria. This has increased the demand of artemisinin, already a scarce commodity. Synthesis of artemisinin is not yet commercially viable. Extensive use of available ACTs will invariably lead to emergence of resistance to these combinations. Thus, there is need to search for new artemisinin-based synthetic, inexpensive, synergistic combinations to reduce dependence on artemisinin. In vitro cultures of P. falciparum provide an appropriate system for identification of such new combinations. We evaluated interactions of artemisinin with triclosan or ketoconazole against blood stages of P. falciparum by a fixed-ratio isobologram method. Artemisinin shows mild synergistic interaction with triclosan and slight to marked antagonism with ketoconazole in vitro. These antiplasmodial interactions, however, require confirmation using in vivo model systems.
PERSISTENCE OF BRUGIA MALAYI DNA IN VECTOR AND NON-VECTOR MOSQUITOES: IMPLICATIONS FOR XENOMONITORING AND TRANSMISSION MONITORING OF LYMPHATIC FILARIASIS
Authors: FISCHER PETER , ERICKSON SARA M. , FISCHER KERSTIN , FUCHS JEREMY F. , RAO RAMAKRISHNA U. , CHRISTENSEN BRUCE M. , WEIL GARY J.
Published: September 2018

Xenomonitoring (detection of filarial larvae or their DNA in mosquitoes) is a sensitive marker for assessing the endemicity of filariasis and a useful tool for evaluating elimination programs. To examine the fate of microfilariae (mf) and filarial DNA in vector competent and non-competent mosquito strains, we compared the detection of Brugia malayi parasites by dissection and by quantitative real-time polymerase chain reaction (PCR) in three different mosquito strains. We conclude that PCR is much more sensitive than dissection for detecting filarial larvae, especially their remnants in mosquitoes. However, parasite DNA can be detected in both vector and non-vector mosquitoes for two weeks or longer after they ingest mf-positive blood. Thus, although xenomonitoring with vector and non-vector mosquito species may be a sensitive method for indirectly detecting filarial parasites in human populations, positive test results for parasite DNA in mosquitoes do not necessarily prove that transmission is ongoing in the study area.
ASYMPTOMATIC COLITIS IN NATURALLY INFECTED DOGS WITH LEISHMANIA INFANTUM: A PROSPECTIVE STUDY
Authors: ADAMAMA-MORAITOU KATERINA K. , RALLIS TIMOLEON S. , KOYTINAS ALEXANDER F. , TONTIS DIMITRIS , PLEVRAKI KATERINA , KRITSEPI MARIA
Published: September 2018

A total of 31 dogs with naturally occurring and symptomatic leishmaniasis (Leishmania infantum), but without historical or clinical evidence of overt colitis, were included in this study. With owners’ consent, a colonoscopy was performed in all these dogs, revealing patches of hyperemic, edematous, irregular, and mildly erosive colonic mucosa in 25.8% of the animals. Biopsies were obtained from the colonic mucosa and stained with hematoxylin-eosin (histopathology) and avidin-biotin-peroxidase technique (immunohistochemical detection of parasites). Leishmania amastigotes were detected immunohistochemically in 32.3% of the dogs. The most common inflammatory pattern in the colonic mucosa of these dogs was pyogranulomatous (90%), whereas in the dogs without Leishmania amastigotes immunohistochemically detected in the colonic mucosa (67.7%), there was no evidence of gross and microscopic lesions. Also, in 2 of the 10 dogs in which parasites were detected immunohistochemically in the colonic mucosa, no lesions could be detected on colonoscopy. There was no correlation between the dogs with or without parasites detected in the colonic mucosa regarding the sex, age, or the type of diet of these animals. However, the positive correlation (P < 0.001) found between colonic parasitism and gross lesions detected on colonoscopy would justify the inclusion of canine leishmaniasis in the list of differentials of canine chronic or recurrent colitis.
GENETIC STRUCTURE OF LUTZOMYIA (NYSSOMYIA) INTERMEDIA POPULATIONS FROM TWO ECOLOGIC REGIONS IN BRAZIL WHERE TRANSMISSION OF LEISHMANIA (VIANNIA) BRAZILIENSIS REFLECTS DISTINCT ECO-EPIDEMIOLOGIC FEATURES
Authors: DE SOUZA ROCHA LEONARDO , FALQUETO ALOÍSIO , DOS SANTOS CLAUDINEY BIRAL , GRIMALDI GABRIEL , CUPOLILLO ELISA
Published: September 2018

Randomly amplified polymorphic DNA (RAPD) analysis was performed to infer the magnitude and pattern of genetic differentiation among Lutzomyia (Nyssomyia) intermedia populations from two ecologic regions in southeast Brazil where transmission of American cutaneous leishmaniasis (ACL) by L. (Viannia) braziliensis reflects distinct eco-epidemiologic features. Two hundred thirty-five bands from six primers were analyzed for genetic variation within and between sand fly populations. A lower level of intrapopulational variability was found in domestic sand flies (compared with the peridomestic population). Gene flow FST estimates indicated homogeneity in the studied population, with limited population substructuring, but with a tendency of sand fly vectors to form clusters by micro-habitat (domestic and peridomestic). The level of genetic structuring of Lu. intermedia population from each ecologic region is distinct and may reflect association or independence between the domestic and the peridomestic habitats in rural and periurban areas, respectively, both reflecting distinct characteristics of the transmission cycle of ACL.
CROSS-PROTECTION AGAINST LEISHMANIA DONOVANI BUT NOT L. BRAZILIENSIS CAUSED BY VACCINATION WITH L. MAJOR SOLUBLE PROMASTIGOTE EXOGENOUS ANTIGENS IN BALB/C MICE
Authors: TONUI WILLY K. , TITUS RICHARD G.
Published: September 2018

Vaccinating with soluble Leishmania major promastigote exogenous antigens (LmSEAgs) protects mice against challenge with L. major. To explore the potential of LmSEAgs to cross-protect against infection with other species of Leishmania, BALB/c mice were immunized with LmSEAgs prior to challenge with either L. donovani or L. braziliensis promastigotes. Such mice were protected against L. donovani but not L. braziliensis infection. Leishmania braziliensis–infected mice developed lesions that were not significantly different from those of controls and that contained 13-fold more parasites. In contrast, immunized mice infected with L. donovani were protected as illustrated by low splenic parasite loads (as much as 4,913-fold fewer parasites). This protection corresponded to significant increases in gamma interferon and low production of interleukin-4 (IL-4) IL-4 or IL-10, which suggested an enhanced type 1 response.
MALARIA RISK FACTORS IN AMERINDIAN CHILDREN IN FRENCH GUIANA
Authors: HUSTACHE SARAH , NACHER MATHIEU , DJOSSOU FÉLIX , CARME BERNARD
Published: September 2018

Malaria is a major public health problem in French Guiana. This study was conducted in children <1–5 years of age in Camopi, an Amerindian village in eastern French Guiana. Medical, environmental, and behavioral predictive factors of malaria were studied using the Kaplan-Meier method and Cox modeling. Variables included were clearing vegetation around the home (hazard ratio [HR] = 0.62, 95% confidence interval [CI] = 0.43–0.88 for 50–75% cleared and HR = 0.5, 95% CI = 0.31–0.81 for > 75% cleared) relative to homes surrounded by vegetation; distance of a home from a river (HR = 0.56, 95% CI = 0.37–0.85 for distances between 20 and 40 meters, HR = 0.72, 95% CI = 0.47–1.09 for distances between 40 and 80 meters, HR = 0.52, 95% CI = 0.28–0.94 for distances between 80 and 120 meters, and HR = 0.5, 95% CI = 0.30–0.86 for distances > 120 meters) relative to distances < 20 meters; the number of occupants in the home (HR = 1.54, 95% CI = 0.98–2.44 for 7 occupants, HR = 1.9, 95% CI = 1.29–2.81 for 8–11 occupants, and HR = 2.03, 95% CI = 1.27–3.23 for > 11 occupants); clothing (HR = 0.64, 95% CI = 0.46–0.90 for children wearing western-style clothes relative to those wearing the traditional kalimbe), and ethnicity (Wayampi children had a lower hazard of malaria relative to Emerillon children: HR = 0.55, 95% CI = 0.40–0.80). The environment near the home was strongly associated with malaria. This suggests that simple pragmatic protection measures would be useful in Camopi.
EFFICACY OF SINGLE-DOSE DIETHYLCARBAMAZINE COMPARED WITH DIETHYLCARBAMAZINE COMBINED WITH ALBENDAZOLE AGAINST WUCHERERIA BANCROFTI INFECTION IN PAPUA NEW GUINEA
Authors: BOCKARIE MOSES J. , TAVUL LIVINGSTONE , IBAM IRVIN , KASTENS WILL , HAZLETT FRED , TISCH DANIEL J. , ALPERS MICHAEL P. , KAZURA JAMES W.
Published: September 2018

The efficacy of diethylcarbamazine alone was compared with diethylcarbamazine plus albendazole in residents of an island in Papua New Guinea endemic for Wuchereria bancrofti. There was no statistically significant difference between the two drug regimens in decreasing the microfilaria positive rate at 12 and 24 months after a single-dose treatment with either regimen, e.g., 50.0% clearance of microfilaria at 24 months for diethylcarbamazine alone versus 65.7% clearance of microfilaria for diethylcarbamazine plus albendazole (P > 0.05). In contrast, diethylcarbamazine plus albendazole resulted in a significant decrease in Og4C3 antigen prevalence (17%; P = 0.003) at 24 months whereas diethylcarbamazine did not (10%; P = 0.564). These data showed no statistically significant difference in the efficacy of the two drug regimens in lowering the microfilaria reservoir, but they support the use of diethylcarbamazine combined with albendazole in mass treatment programs on the basis of greater activity against adult worms.
AGE-DEPENDENT DISTRIBUTION OF PLASMODIUM FALCIPARUM GAMETOCYTES QUANTIFIED BY PFS25 REAL-TIME QT-NASBA IN A CROSS-SECTIONAL STUDY IN BURKINA FASO
Authors: OUÉDRAOGO ANDRÉ LIN , SCHNEIDER PETRA , DE KRUIJF MARCEL , NÉBIÉ ISSA , VERHAVE JAN PETER , CUZIN-OUATTARA NADINE , SAUERWEIN ROBERT W.
Published: September 2018

Sexual stages of Plasmodium falciparum play a key role in the transmission of malaria. Studies on gametocytes are generally based on microscopic detection, but more sensitive detection methods for P. falciparum gametocytes frequently detect sub-patent gametocytes. We used Pfs25 mRNA quantitative-nucleic acid sequence-based amplification (QT-NASBA) to quantify gametocytes in 412 samples from a cross-sectional study in Burkina Faso, covering all age groups, to determine age-related patterns in gametocyte carriage and gametocyte density. The more sensitive QT-NASBA technique gave estimates of gametocyte prevalence 3.3-fold higher than microscopy (70.1% versus 21.4%, respectively). Prevalence of gametocytes significantly decreased with age. Our data suggest that asexual parasite densities are primarily responsible for the age-related decrease of gametocyte prevalence, possibly because of developing asexual stage immunity. Gametocyte densities decrease also with age, primarily because of decreasing asexual parasite densities; only a small but significant age effect on gametocyte density may be caused by developing sexual stage–specific immunity.
THROMBOCYTOPENIA ASSOCIATED WITH DENGUE HEMORRHAGIC FEVER RESPONDS TO INTRAVENOUS ADMINISTRATION OF ANTI-D (RH0-D) IMMUNE GLOBULIN
Authors: DE CASTRO REYNALDO ANGELO C. , DE CASTRO JO-ANNE A. , BAREZ MARIE YVETTE C. , FRIAS MELCHOR V. , DIXIT JITENDRA , GENEREUX MAURICE
Published: September 2018

Severe thrombocytopenia and increased vascular permeability are two major characteristics of dengue hemorrhagic fever (DHF). An immune mechanism of thrombocytopenia due to increased platelet destruction appears to be operative in patients with DHF (see Saito et al., 2004, Clin Exp Immunol 138: 299–303; Mitrakul, 1979, Am J Trop Med Hyg 26: 975–984; and Boonpucknavig, 1979, Am J Trop Med Hyg 28: 881–884). The interim data of two randomized placebo controlled trials in patients (N = 47) meeting WHO criteria for dengue hemorrhagic fever (DHF) with severe thrombocytopenia (platelets ≤ 50,000/mm3) reveal that the increase in platelet count with anti-D immune globulin (WinRho® SDF), 50 μg/kg (250 IU/kg) intravenously is more brisk than the placebo group. The mean maximum platelet count of the anti-D–treated group at 48 hours was 91,500/mm3 compared with 69,333/mm3 in the placebo group. 75% of the anti-D–treated group demonstrated an increase of platelet counts ≥ 20,000 compared with only 58% in the placebo group. These data suggest that treatment of severe thrombocytopenia accompanying DHF with anti-D may be a useful and safe therapeutic option.
DIFFICULTY IN DIAGNOSIS AND TREATMENT OF DENGUE HEMORRHAGIC FEVER IN PATIENTS WITH CHRONIC RENAL FAILURE: REPORT OF THREE CASES OF MORTALITY
Authors: KUO MEI-CHUAN , CHANG JER-MING , LU PO-LIANG , CHIU YI-WEN , CHEN HUNG-CHUN , HWANG SHANG-JYH
Published: September 2018

In 2002, an outbreak of dengue fever (DF) in Taiwan caused mortality in some patients with chronic renal failure (CRF). We report three cases of CRF who died of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) despite an intensive care process. The difficulty in diagnosis and the treatment dilemma attributable to ambiguity in symptoms and signs between CRF and DF may delay the diagnosis, contributing to a high risk of mortality. The narrow window of fluid tolerance in patients with CRF further hampers the success of resuscitation in DHF and DSS. Continuous venous to venous hemodialysis (CVVHD) is helpful in managing a condition with unstable hemodynamics. However, to decrease mortality, the physician must pay great attention to ensure an early awareness of DHF/DSS and deliver a prompt and aggressive treatment of patients of dengue viral infections with chronic renal failure.
RECOMBINANT ALPHAVIRUSES ARE SAFE AND USEFUL SEROLOGICAL DIAGNOSTIC TOOLS
Authors: NI HAOLIN , YUN NADEZHDA E. , ZACKS MICHELE A. , WEAVER SCOTT C. , TESH ROBERT B. , DA ROSA AMELIA P. TRAVASSOS , POWERS ANN M. , FROLOV ILYA , PAESSLER SLOBODAN
Published: September 2018

Serological assays for diagnosis of Venezuelan equine encephalitis virus (VEEV) currently require bio-safety level 3 facilities and select agent certification to produce antigens, reference sera, or viral stocks. Rapid identification of VEEV infection is required to respond to human and equine outbreaks of encephalitis caused by that virus and can be useful for epidemiologic surveillance. Alphavirus (Sindbis)-based recombinant viruses that express VEEV structural proteins are attenuated in animal models, thus representing an alternative to the handling of virulent infectious virus. Virus and viral antigens from recombinant Sindbis/VEE constructs engineered to express structural proteins from multiple VEEV subtypes were evaluated as diagnostic reagents in VEEV-specific serological assays, e.g., plaque reduction neutralization test (PRNT), hemagglutination inhibition (HI) assay, and complement fixation (CF) test. Chimeric viruses were produced efficiently in cell culture and were as effective as the parental virus for identifying infection of humans, horses, and rodents in these serological assays.
WEST NILE VIRUS INFECTION IN TREE SQUIRRELS (RODENTIA: SCIURIDAE) IN CALIFORNIA, 2004–2005
Authors: PADGETT KERRY A. , REISEN WILLIAM K. , KAHL-PURCELL NICOLE , FANG YING , CAHOON-YOUNG BARBARA , CARNEY RYAN , ANDERSON NANCY , ZUCCA LYNDA , WOODS LESLIE , HUSTED STAN , KRAMER VICKI L.
Published: September 2018

West Nile virus (WNV) transmission generally involves a mosquito vector and an avian reservoir host, with mammals as incidental hosts. Although most mammalian WNV infections cause low or no morbidity or mortality, tree squirrels are susceptible to WNV-associated neurologic disease with infection prevalence comparable to that in dead birds. Positive species included fox squirrel (Sciurus niger), western gray squirrel (S. griseus), and eastern gray squirrel (S. carolinensis). Kidney tissue (dissected and swabbed), and oropharyngeal (oral) swab samples from tree squirrels submitted by California vector control and rehabilitation agencies were tested by reverse transcription–polymerase chain reaction; cycle threshold values were similar for all three samples, ranging from 21.9 to 26.5. Kidney tissue was more sensitive than oral swabs for detecting WNV in squirrels. Three of 36 live neurologic tree squirrels had viremia approximately 5 log10 plaque-forming units/mL or greater, similar to WNV-infected birds. Tree squirrels are useful in WNV surveillance and provide localized evidence of WNV transmission to mammals.
EFFICIENT ORAL INFECTION OF CULEX PIPIENS QUINQUEFASCIATUS BY RIFT VALLEY FEVER VIRUS USING A COTTON STICK SUPPORT
Authors: MOUTAILLER SARA , BOULOY MICHÈLE , FAILLOUX ANNA-BELLA
Published: September 2018

Transmission experiments are essential to assess vector competence. In an attempt to study Rift Valley fever virus (RVFV) transmission in its arthropod vector, disseminated infection rates were measured in Culex pipiens quinquefasciatus exposed to Clone 13, an avirulent variant of RVFV. We compared the classic system of glass feeders covered with different membranes (0–1%) with an alternative system in which a cotton stick is used as a support of a blood meal. The latter system showed the highest successful feeding rate (80%). Using this system, we optimized two parameters to obtain the highest numbers of engorged females and thus the highest numbers of females with disseminated infection: 1) use of freshly collected washed erythrocytes and 2) duration of the extrinsic incubation period of at least 14 days after infection.
DETERMINANTS OF BED NET USE IN THE GAMBIA: IMPLICATIONS FOR MALARIA CONTROL
Authors: WISEMAN VIRGINIA , SCOTT ANTHONY , MCELROY BRENDAN , CONTEH LESONG , STEVENS WARREN
Published: September 2018

Malaria is still one of the biggest health threats in the developing world, with an estimated 300 million episodes per year and one million deaths, most of which are in sub-Saharan Africa. Although the efficacy and cost-effectiveness of treated bed nets has been widely reported, little is known about the range, strength, or interaction between different factors that influence their demand at the household level. This study modeled the determinants of bed net ownership as well as the factors that influence the number of bed nets purchased. Data was collected from 1,700 randomly selected households in the Farafenni region of The Gambia. Interviews were also held with 129 community spokespersons to explore the extent to which community level factors such as the quality of roads and access to market centers also influence demand for bed nets. The results of each model of demand and their policy implications are discussed.
MULTIPLEX PCR ASSAY FOR THE DETECTION OF ANOPHELES FLUVIATILIS SPECIES COMPLEX, HUMAN HOST PREFERENCE, AND PLASMODIUM FALCIPARUM SPOROZOITE PRESENCE, USING A UNIQUE MOSQUITO PROCESSING METHOD
Authors: MOHANTY AMITAV , KAR PRIYANKA , MISHRA KIRTI , SINGH DURG V. , MOHAPATRA NAMITA , KAR SANTANU K. , DASH ADITYA P. , HAZRA RUPENANGSHU K.
Published: September 2018

A multiplex PCR assay has been developed for detection of Anopheles fluviatilis cryptic species, their human host preference, and Plasmodium falciparum presence in the mosquito. PCR conditions were optimized using primer sets specific for A. fluviatilis cryptic species, Homo sapiens, and P. falciparum and evaluated with field-collected mosquitoes. A unique mosquito processing method was used for screening P. falciparum carrying capacity and human host preference of A. fluviatilis mosquitoes in first-round multiplex PCR. The vectorial status of the mosquito for P. falciparum parasite was confirmed in second-round PCR. Of the 121 collected mosquitoes, 92 were of S type, 26 of T type, and 3 were of other types. Human host preference was dominant in S type, of which 4% were P. falciparum sporozoite positive. This assay and processing method can also be used to evaluate vector competence of other anophelines.
RARE PLASMODIUM FALCIPARUM MEROZOITE SURFACE PROTEIN 1 19-KDA (MSP-119) HAPLOTYPES IDENTIFIED IN MALI USING HIGH-THROUGHPUT GENOTYPING METHODS
Authors: TAKALA SHANNON L. , SMITH DAVID L. , THERA MAHAMADOU A. , COULIBALY DRISSA , DOUMBO OGOBARA K. , PLOWE CHRISTOPHER V.
Published: September 2018

Genetic diversity in malaria vaccine antigens may compromise malaria vaccine efficacy, so it is important to understand this diversity and the processes that generate it. By applying new high-throughput genotyping methods to a large sample of infections from Mali (N = 1369), seven new 19-kDa merozoite surface protein 1 (MSP-119) haplotypes were identified. Herein we report the sequences of these new haplotypes and discuss their possible origins. Although they are present in < 1% of the samples examined, the existence of these rare haplotypes reveals a greater degree of diversity at this locus than previously reported and highlights the potential for Plasmodium to evolve under selective pressure from the immune system and from such interventions as vaccines and drugs.
ASSESSMENT OF TRIATOMA DIMIDIATA DISPERSAL IN THE YUCATAN PENINSULA OF MEXICO BY MORPHOMETRY AND MICROSATELLITE MARKERS
Authors: DUMONTEIL ERIC , TRIPET FRÉDÉRIC , RAMIREZ-SIERRA MARIA JESUS , PAYET VINCENT , LANZARO GREGORY , MENU FRÉDÉRIC
Published: September 2018

In the Yucatán Peninsula of Mexico, the main vector of Chagas disease is Triatoma dimidiata. Field studies suggest that natural transmission occurs through transient and seasonal invasion of houses by sylvatic/peridomestic triatomines, rather than through persistent domiciliated bug populations. We investigated the genetic structure of T. dimidiata populations, using morphometry and microsatellite markers, to assess dispersal of individuals in this triatomine species and to understand the dynamics of domestic infestation. We observed low phenotypic and genetic differentiation among populations from different villages, with an FST of only 0.0553, which suggested a weak but significant population structure at this level. Similarly low but significant differences were observed among populations from the same village but different biotopes (sylvatic, peridomestic, and domestic), with FST values ranging from 0.0096 to 0.0455. These data suggested elevated dispersal of bugs between biotopes (Nm = 5–25), which was confirmed by likelihood and Bayesian assignment tests. A proportion of bugs collected within domiciles were significantly assigned to peridomestic and sylvatic areas. This study showed that T. dimidiata has important dispersal capabilities that can explain the seasonal pattern of domicile infestation by peridomestic and sylvatic bugs. Therefore, dispersal should be taken into account in the design of effective vector control strategies.
REDUCED SERUM CONCENTRATIONS OF RETINOL AND α-TOCOPHEROL AND HIGH CONCENTRATIONS OF HYDROPEROXIDES ARE ASSOCIATED WITH COMMUNITY LEVELS OF S. MANSONI INFECTION AND SCHISTOSOMAL PERIPORTAL FIBROSIS IN ETHIOPIAN SCHOOL CHILDREN
Authors: BERHE NEGA , HALVORSEN BENTE L. , GUNDERSEN THOMAS E. , MYRVANG BJØRN , GUNDERSEN SVEIN G. , BLOMHOFF RUNE
Published: September 2018

To study the relationship between micronutrient malnutrition and schistosomiasis mansoni, a cross-sectional study was undertaken involving 421 schoolchildren (mean age 12.6 years; 333 from schistosomiasis mansoni–endemic villages (Workemado and Sille) and 88 non-endemic controls from Sheno). Prevalence of schistosomiasis mansoni infection in Workemado and Sille was comparable (90.6% versus 95%, respectively), and prevalence of PPF in Workemado was significantly higher than in Sille (7.0% versus 0.6%, P < 0.001). Compared with non-endemic controls, serum retinol concentrations were significantly lower and hydroperoxides were significantly higher in subjects from schistosomiasis mansoni–endemic areas. Furthermore, serum α-tocopherol concentrations in subjects from an area with high prevalence of PPF were significantly reduced while the concentrations in subjects from an area with low prevalence of PPF were comparable to the levels found in non-endemic healthy controls. In conclusion, micronutrient malnutrition and oxidative stress are associated with Schistosoma mansoni infection and levels of schistosomal PPF.
Is There Evidence for Dual Causation Between Malaria and Socioeconomic Status? Findings From Rural Tanzania
Authors: Somi Masha F. , Butler James R. G. , Vahid Farshid , Njau Joseph , Kachur S. Patrick , Abdulla Salim
Published: September 2018

Malaria’s relationship with socioeconomic status at the macroeconomic level has been established. This is the first study to explore this relationship at the microeconomic (household) level and estimate the direction of association. Malaria prevalence was measured by parasitemia, and household socioeconomic status was measured using an asset based index. Results from an instrumental variable probit model suggest that socioeconomic status is negatively associated with malaria parasitemia. Other variables that are significantly associated with parasitemia include age of the individual, use of a mosquito net on the night before interview, the number of people living in the household, whether the household was residing at their farm home at the time of interview, household wall construction, and the region of residence. Matching estimators indicate that malaria parasitemia is associated with reduced household socioeconomic status.