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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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