Immunology and Microbiology › Parasitology

Parasites and Host Interactions

Works Count: 70256

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Description

This cluster of papers focuses on the global impact, epidemiology, control strategies, and immune responses related to helminth infections, with a specific emphasis on schistosomiasis and soil-transmitted helminths. The papers cover topics such as disease burden, neglected tropical diseases, immunomodulation by parasites, and the use of praziquantel for treatment.

Keywords

Helminth Infections; Schistosomiasis; Soil-Transmitted Helminths; Neglected Tropical Diseases; Immunomodulation; Parasite Control; Disease Burden; Praziquantel; Immune Regulation; Global Epidemiology

The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of the adult worms

1965-11-01

S. R. Smithers , R. J. Terry

At present many laboratories throughout the world are studying the chemotherapy and immunology of Schistosoma mansoni in laboratory hosts. Many workers judge the success or failure of their attempts to … At present many laboratories throughout the world are studying the chemotherapy and immunology of Schistosoma mansoni in laboratory hosts. Many workers judge the success or failure of their attempts to cure or immunize these hosts from the ratio of the number of living adult worms recovered to the number of infecting cercariae. This ratio is affected, however, not only by the efficacy of any treatment, but also by the methods used to infect the animals and to recover the worms. If these methods result in widely varying worm recoveries amongst the animals in any experimental group, then small but significant effects of treatment might well be missed. Alternatively, such large experimental groups must be used that the work becomes tedious to perform and depends upon the availability of a great deal of technical assistance. This paper describes techniques which are rapid and do not require great skill in their performance. More important, in our hands they have given very consistent results. In this respect, particularly, we believe that these techniques have advantages over others which are currently practised. The techniques described here are those which were used in other investigations reported in this journal (Smithers & Terry, 1965 a, b ). The strain of S. mansoni used throughout this work was isolated in Puerto Rico and was obtained through the courtesy of Dr W. B. DeWitt of the National Institutes of Health. The parasite is maintained in an albino strain of Australorbis glabratus (Newton, 1955). Snails are exposed individually to ten miracidia overnight at 27 °C.

A simple device for quantitative stool thick-smear technique in Schistosomiasis mansoni.

1972-11-01

Naftale Katz , A Chaves , J. Pellegrino

Schistosomiasis

2002-04-18

Allen G. Ross , Paul B. Bartley , Adrian Sleigh +4 more

Schistosomiasis is a parasitic-worm infection that affects about 200 million people in 74 countries. Despite major advances in treatment and control, this tropical disease continues to spread to new geographic … Schistosomiasis is a parasitic-worm infection that affects about 200 million people in 74 countries. Despite major advances in treatment and control, this tropical disease continues to spread to new geographic areas. This review summarizes the manifestations of this disease, its diagnosis, medical treatment, and prophylaxis, and the prospects for a vaccine.

Liver Fluke Induces Cholangiocarcinoma

2007-07-03

Banchob Sripa , Sasithorn Kaewkes , Paiboon Sithithaworn +7 more

Liver fl uke infection caused by Opisthorchis viverrini, O. felineus, and Clonorchis sinensis is a major public health problem in East Asia and Eastern Europe.Currently, more than 600 million people … Liver fl uke infection caused by Opisthorchis viverrini, O. felineus, and Clonorchis sinensis is a major public health problem in East Asia and Eastern Europe.Currently, more than 600 million people are at risk of infection with these trematodes [1].O. viverrini is endemic in Southeast Asian countries, including Thailand, Lao People's Democratic Republic, Vietnam, and Cambodia [2], and C. sinensis infection is common in rural areas of Korea and China.Opisthorchiasis has been extensively studied in Thailand, where an estimated 6 million people are infected with the liver fl uke (calculated from overall 9.4% prevalence within the population in 2001) [3].Infection with these food-borne parasites is prevalent in areas where uncooked cyprinoid fi sh are a staple of the diet.Due to poor sanitation practices and inadequate sewerage infrastructure, people infected with O. viverrini and C. sinensis pass parasite eggs in their faeces into natural water reservoirs, where the parasite eggs are eaten by intermediate host snails, for example, aquatic snails of the genus Bithynia, the fi rst intermediate host of O. viverrini.After hatching, free swimming parasites, called cercariae, are released from the infected snails.Cercariae then locate their next intermediate host, cyprinoid fi shes, encyst in the fi ns, skin, and muscles of the fi sh, and become metacercariae.The metacercariae are infective to humans and other fi sh-eating mammals upon ingestion of raw or undercooked fi sh in dishes such as koi-pla (Figure 1), and in turn the parasite's life cycle is completed (Figure 2).Most people with opisthorchiasis or clonorchiasis have no symptoms.Only 5%-10% of infected people, in general those with heavy fl uke infections, have non-specifi c symptoms such as right upper quadrant abdominal pain, fl atulence, and fatigue [4,5].Enlargement of the gall bladder can be detected by ultrasonography, and is reversed after elimination of fl ukes by praziquantel [6].Nonetheless, heavy, long-standing infection is associated with a number of hepatobiliary diseases, including cholangitis, obstructive jaundice, hepatomegaly, fi brosis of the periportal system, cholecystitis, and cholelithiasis [7][8][9][10].Moreover, both experimental and epidemiologic evidence strongly implicates liver fl uke infection in the aetiology of one of the liver cancer subtypes-cholangiocarcinoma (CCA), or cancer of the bile ducts [2,11].The pathology of clonorchiasis was recently reviewed in detail by Rim [12].Unlike O. viverrini, C. sinensis is not considered a Group I carcinogen (known to be carcinogenic in humans) [2], despite its widespread prevalence [13].In

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Downregulation of Th1 cytokine production accompanies induction of Th2 responses by a parasitic helminth, Schistosoma mansoni.

1991-01-01

Edward J. Pearce , Patricia Caspar , Jean‐Marie Grzych +2 more

In the mouse, infection with Schistosoma mansoni results in an egg-producing infection and associated disease, whereas vaccination with attenuated larval stages produces a substantial and specific immunity in the absence … In the mouse, infection with Schistosoma mansoni results in an egg-producing infection and associated disease, whereas vaccination with attenuated larval stages produces a substantial and specific immunity in the absence of egg-induced pathology. Preliminary data showing enhanced interleukin-5 (IL-5) production by T cells from infected mice and interferon gamma (IFN-gamma) synthesis by cells from vaccinated animals (7), suggested differential CD4+ subset stimulation by the different parasite stimuli. To confirm this hypothesis, lymphocytes from vaccinated or infected animals were compared for their ability to produce IFN-gamma and IL-2 (secreted by Th1 cells) as compared with IL-4 and IL-5 (characteristic Th2 cytokines). After stimulation with specific antigen or mitogen, T cells from vaccinated mice or prepatently infected animals responded primarily with Th1 lymphokines, whereas lymphocytes from patently infected mice instead produced Th2 cytokines. The Th2 response in infected animals was shown to be induced by schistosome eggs and directed largely against egg antigens, whereas the Th1 reactivity in vaccinated mice was triggered primarily by larval antigens. Interestingly, Th1 responses in mice carrying egg-producing infections were found to be profoundly downregulated. Moreover, the injection of eggs into vaccinated mice resulted in a reduction of antigen and mitogen-stimulated Th1 function accompanied by a coincident expression of Th2 responses. Together, the data suggest that coincident with the induction of Th2 responses, murine schistosome infection results in an inhibition of potentially protective Th1 function. This previously unrecognized downregulation of Th1 cytokine production may be an important immunological consequence of helminth infection related to host adaptation.

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Trichuris suis therapy for active ulcerative colitis: A randomized controlled trial

2005-04-01

Robert W. Summers , David E. Elliott , Joseph F. Urban +2 more

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Alternative Macrophage Activation Is Essential for Survival during Schistosomiasis and Downmodulates T Helper 1 Responses and Immunopathology

2004-05-01

De’Broski R. Herbert , Christoph Hölscher , Markus Mohrs +7 more

Control of Neglected Tropical Diseases

2007-09-05

Peter J. Hotez , David Molyneux , Alan Fenwick +4 more

In addition to malaria, tuberculosis, and human immunodeficiency virus infection, several other infectious diseases are associated with substantial morbidity and mortality. In particular, 13 tropical diseases infect billions of people … In addition to malaria, tuberculosis, and human immunodeficiency virus infection, several other infectious diseases are associated with substantial morbidity and mortality. In particular, 13 tropical diseases infect billions of people and cause disabilities such as blindness and heart failure, especially in persons who live in impoverished conditions. This review article describes approaches to the global control of these diseases.

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The global status of schistosomiasis and its control

2000-10-01

Lester Chitsulo , Dirk Engels , Antonio Montresor +1 more

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C-REACTIVE PROTEIN FIFTY YEARS ON

1981-03-01

Mark B. Pepys

Efficacy of Current Drugs Against Soil-Transmitted Helminth Infections

2008-04-22

Jennifer Keiser , Jürg Utzinger

More than a quarter of the human population is likely infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) in highly endemic areas. Preventive chemotherapy is the mainstay of … More than a quarter of the human population is likely infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) in highly endemic areas. Preventive chemotherapy is the mainstay of control, but only 4 drugs are available: albendazole, mebendazole, levamisole, and pyrantel pamoate.To assess the efficacy of single-dose oral albendazole, mebendazole, levamisole, and pyrantel pamoate against A lumbricoides, hookworm, and T trichiura infections.A systematic search of PubMed, ISI Web of Science, ScienceDirect, the World Health Organization library database, and the Cochrane Central Register of Controlled Trials (1960 to August 2007).From 168 studies, 20 randomized controlled trials were included.Information on study year and country, sample size, age of study population, mean infection intensity before treatment, diagnostic method used, time between evaluations before and after treatment, cure rate (the percentage of individuals who became helminth egg negative following treatment with an anthelminthic drug), egg reduction rate, adverse events, and trial quality was extracted. Relative risk, including a 95% confidence interval (CI), was used to measure the effect of the drugs on the risk of infection prevalence with a random-effects model.Single-dose oral albendazole, mebendazole, and pyrantel pamoate for infection with A lumbricoides resulted in cure rates of 88% (95% CI, 79%-93%; 557 patients), 95% (95% CI, 91%-97%; 309 patients), and 88% (95% CI, 79%-93%; 131 patients), respectively. Cure rates for infection with T trichiura following treatment with single-dose oral albendazole and mebendazole were 28% (95% CI, 13%-39%; 735 patients) and 36% (95% CI, 16%-51%; 685 patients), respectively. The efficacy of single-dose oral albendazole, mebendazole, and pyrantel pamoate against hookworm infections was 72% (95% CI, 59%-81%; 742 patients), 15% (95% CI, 1%-27%; 853 patients), and 31% (95% CI, 19%-42%; 152 patients), respectively. No pooled relative risks could be calculated for pyrantel pamoate against T trichiura and levamisole for any of the parasites investigated.Single-dose oral albendazole, mebendazole, and pyrantel pamoate show high cure rates against A lumbricoides. For hookworm infection, albendazole was more efficacious than mebendazole and pyrantel pamoate. Treatment of T trichiura with single oral doses of current anthelminthics is unsatisfactory. New anthelminthics are urgently needed.

Incorporating a Rapid-Impact Package for Neglected Tropical Diseases with Programs for HIV/AIDS, Tuberculosis, and Malaria

2006-01-26

Peter J. Hotez , David Molyneux , Alan Fenwick +3 more

Hotez et al. argue that achieving success in the global fight against HIV/AIDS, tuberculosis, and malaria may well require a concurrent attack on the neglected tropical diseases. Hotez et al. argue that achieving success in the global fight against HIV/AIDS, tuberculosis, and malaria may well require a concurrent attack on the neglected tropical diseases.

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Helminth infections: the great neglected tropical diseases

2008-03-29

Peter J. Hotez , Paul J. Brindley , Jeffrey M. Bethony +3 more

Helminths are parasitic worms. They are the most common infectious agents of humans in developing countries and produce a global burden of disease that exceeds better-known conditions, including malaria and … Helminths are parasitic worms. They are the most common infectious agents of humans in developing countries and produce a global burden of disease that exceeds better-known conditions, including malaria and tuberculosis. As we discuss here, new insights into fundamental helminth biology are accumulating through newly completed genome projects and the nascent application of transgenesis and RNA interference technologies. At the same time, our understanding of the dynamics of the transmission of helminths and the mechanisms of the Th2-type immune responses that are induced by infection with these parasitic worms has increased markedly. Ultimately, these advances in molecular and medical helminth biology should one day translate into a new and robust pipeline of drugs, diagnostics, and vaccines for targeting parasitic worms that infect humans.

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Neglected Tropical Diseases in Sub-Saharan Africa: Review of Their Prevalence, Distribution, and Disease Burden

2009-08-24

Peter J. Hotez , Aruna M Kamath

The neglected tropical diseases (NTDs) are the most common conditions affecting the poorest 500 million people living in sub-Saharan Africa (SSA), and together produce a burden of disease that may … The neglected tropical diseases (NTDs) are the most common conditions affecting the poorest 500 million people living in sub-Saharan Africa (SSA), and together produce a burden of disease that may be equivalent to up to one-half of SSA's malaria disease burden and more than double that caused by tuberculosis. Approximately 85% of the NTD disease burden results from helminth infections. Hookworm infection occurs in almost half of SSA's poorest people, including 40-50 million school-aged children and 7 million pregnant women in whom it is a leading cause of anemia. Schistosomiasis is the second most prevalent NTD after hookworm (192 million cases), accounting for 93% of the world's number of cases and possibly associated with increased horizontal transmission of HIV/AIDS. Lymphatic filariasis (46-51 million cases) and onchocerciasis (37 million cases) are also widespread in SSA, each disease representing a significant cause of disability and reduction in the region's agricultural productivity. There is a dearth of information on Africa's non-helminth NTDs. The protozoan infections, human African trypanosomiasis and visceral leishmaniasis, affect almost 100,000 people, primarily in areas of conflict in SSA where they cause high mortality, and where trachoma is the most prevalent bacterial NTD (30 million cases). However, there are little or no data on some very important protozoan infections, e.g., amebiasis and toxoplasmosis; bacterial infections, e.g., typhoid fever and non-typhoidal salmonellosis, the tick-borne bacterial zoonoses, and non-tuberculosis mycobaterial infections; and arboviral infections. Thus, the overall burden of Africa's NTDs may be severely underestimated. A full assessment is an important step for disease control priorities, particularly in Nigeria and the Democratic Republic of Congo, where the greatest number of NTDs may occur.

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Diversity and dialogue in immunity to helminths

2011-05-25

Judith E. Allen , Rick M. Maizels

Soil-transmitted helminth infections: updating the global picture

2003-10-16

Nilanthi R. de Silva , Simon J. Brooker , Peter J. Hotez +3 more

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Quantification of clinical morbidity associated with schistosome infection in sub-Saharan Africa

2003-05-01

Marieke J. van der Werf , Sake J. de Vlas , Simon Brooker +4 more

Water, Sanitation, Hygiene, and Soil-Transmitted Helminth Infection: A Systematic Review and Meta-Analysis

2014-03-25

Eric Strunz , David G. Addiss , Meredith E. Stocks +3 more

Background Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH). The … Background Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH). The purpose of this study was to quantitatively summarize the relationship between WASH access or practices and soil-transmitted helminth (STH) infection. Methods and Findings We conducted a systematic review and meta-analysis to examine the associations of improved WASH on infection with STH (Ascaris lumbricoides, Trichuris trichiura, hookworm [Ancylostoma duodenale and Necator americanus], and Strongyloides stercoralis). PubMed, Embase, Web of Science, and LILACS were searched from inception to October 28, 2013 with no language restrictions. Studies were eligible for inclusion if they provided an estimate for the effect of WASH access or practices on STH infection. We assessed the quality of published studies with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. A total of 94 studies met our eligibility criteria; five were randomized controlled trials, whilst most others were cross-sectional studies. We used random-effects meta-analyses and analyzed only adjusted estimates to help account for heterogeneity and potential confounding respectively. Use of treated water was associated with lower odds of STH infection (odds ratio [OR] 0.46, 95% CI 0.36–0.60). Piped water access was associated with lower odds of A. lumbricoides (OR 0.40, 95% CI 0.39–0.41) and T. trichiura infection (OR 0.57, 95% CI 0.45–0.72), but not any STH infection (OR 0.93, 95% CI 0.28–3.11). Access to sanitation was associated with decreased likelihood of infection with any STH (OR 0.66, 95% CI 0.57–0.76), T. trichiura (OR 0.61, 95% CI 0.50–0.74), and A. lumbricoides (OR 0.62, 95% CI 0.44–0.88), but not with hookworm infection (OR 0.80, 95% CI 0.61–1.06). Wearing shoes was associated with reduced odds of hookworm infection (OR 0.29, 95% CI 0.18–0.47) and infection with any STH (OR 0.30, 95% CI 0.11–0.83). Handwashing, both before eating (OR 0.38, 95% CI 0.26–0.55) and after defecating (OR 0.45, 95% CI 0.35–0.58), was associated with lower odds of A. lumbricoides infection. Soap use or availability was significantly associated with lower infection with any STH (OR 0.53, 95% CI 0.29–0.98), as was handwashing after defecation (OR 0.47, 95% CI 0.24–0.90). Observational evidence constituted the majority of included literature, which limits any attempt to make causal inferences. Due to underlying heterogeneity across observational studies, the meta-analysis results reflect an average of many potentially distinct effects, not an average of one specific exposure-outcome relationship. Conclusions WASH access and practices are generally associated with reduced odds of STH infection. Pooled estimates from all meta-analyses, except for two, indicated at least a 33% reduction in odds of infection associated with individual WASH practices or access. Although most WASH interventions for STH have focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection. Overall quality of evidence was low due to the preponderance of observational studies, though recent randomized controlled trials have further underscored the benefit of handwashing interventions. Limited use of the Joint Monitoring Program's standardized water and sanitation definitions in the literature restricted efforts to generalize across studies. While further research is warranted to determine the magnitude of benefit from WASH interventions for STH control, these results call for multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts. Please see later in the article for the Editors' Summary

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Immune Regulation by helminth parasites: cellular and molecular mechanisms

2003-09-01

Rick M. Maizels , Maria Yazdanbakhsh

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Helminth immunoregulation: The role of parasite secreted proteins in modulating host immunity

2009-05-05

James P. Hewitson , John R. Grainger , Rick M. Maizels

Helminths are masterful immunoregulators. A characteristic feature of helminth infection is a Th2-dominated immune response, but stimulation of immunoregulatory cell populations, such as regulatory T cells and alternatively activated macrophages, … Helminths are masterful immunoregulators. A characteristic feature of helminth infection is a Th2-dominated immune response, but stimulation of immunoregulatory cell populations, such as regulatory T cells and alternatively activated macrophages, is equally common. Typically, Th1/17 immunity is blocked and productive effector responses are muted, allowing survival of the parasite in a "modified Th2" environment. Drug treatment to clear the worms reverses the immunoregulatory effects, indicating that a state of active suppression is maintained by the parasite. Hence, research has focussed on "excretory-secretory" products released by live parasites, which can interfere with every aspect of host immunity from initial recognition to end-stage effector mechanisms. In this review, we survey our knowledge of helminth secreted molecules, and summarise current understanding of the growing number of individual helminth mediators that have been shown to target key receptors or pathways in the mammalian immune system.

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The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases

2014-07-24

Peter J. Hotez , Miriam Alvarado , Marı́a-Gloria Basáñez +7 more

Asociación entre disminución de la sensibilidad parasitaria in vitro y respuesta terapéutica en pacientes con Leishmaniasis cutánea tratados en el centro dermatológico Federico Lleras Acosta de la ciudad de Bogotá … Asociación entre disminución de la sensibilidad parasitaria in vitro y respuesta terapéutica en pacientes con Leishmaniasis cutánea tratados en el centro dermatológico Federico Lleras Acosta de la ciudad de Bogotá entre

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The immunobiology of schistosomiasis

2002-07-01

Edward J. Pearce , Andrew S. MacDonald

Praziquantel: mechanisms of action, resistance and new derivatives for schistosomiasis

2008-10-31

Michael J. Doenhoff , Donato Cioli , Jürg Utzinger

Purpose of review Praziquantel (PZQ) is the only drug being used to treat human schistosomiasis on a large scale. This review focuses on current knowledge about the mechanisms of action … Purpose of review Praziquantel (PZQ) is the only drug being used to treat human schistosomiasis on a large scale. This review focuses on current knowledge about the mechanisms of action of PZQ, prospects for PZQ resistance, possible future alternative drugs and on exhortations that control of schistosomiasis and other so-called neglected tropical diseases becomes more integrated. Recent findings Schistosome calcium ion (Ca2+) channels are the only moiety so far identified as the molecular target of PZQ, but the evidence remains indirect. In the presence of cytochalasin D worms survive high concentrations of PZQ and experiments with cytochalasin D also indicated that PZQ induced worm death and Ca2+ influx are not correlated. Despite PZQ being widely used, there is no clinically relevant evidence for resistance to date, but worryingly low-cure rates have been recorded in some studies in Africa. Artemisinins and the related 1,2,4-trioxolanes are new promising antischistosomal compounds, as are inhibitors of a schistosome-specific bifunctional enzyme, thioredoxin-glutathione reductase. Summary Use of PZQ will increase in the foreseeable future, whether given alone or coadministered with other anthelminthics in integrated control programmes. PZQ resistance remains a threat and its prevention requires adequate monitoring of current mass drug administration programmes and development of new schistosomicides.

The genome of the blood fluke Schistosoma mansoni

2009-07-01

Matthew Berriman , Brian J. Haas , Philip T. LoVerde +7 more

Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. Here we present analysis of the 363 megabase nuclear genome of the … Schistosoma mansoni is responsible for the neglected tropical disease schistosomiasis that affects 210 million people in 76 countries. Here we present analysis of the 363 megabase nuclear genome of the blood fluke. It encodes at least 11,809 genes, with an unusual intron size distribution, and new families of micro-exon genes that undergo frequent alternative splicing. As the first sequenced flatworm, and a representative of the Lophotrochozoa, it offers insights into early events in the evolution of the animals, including the development of a body pattern with bilateral symmetry, and the development of tissues into organs. Our analysis has been informed by the need to find new drug targets. The deficits in lipid metabolism that make schistosomes dependent on the host are revealed, and the identification of membrane receptors, ion channels and more than 300 proteases provide new insights into the biology of the life cycle and new targets. Bioinformatics approaches have identified metabolic chokepoints, and a chemogenomic screen has pinpointed schistosome proteins for which existing drugs may be active. The information generated provides an invaluable resource for the research community to develop much needed new control tools for the treatment and eradication of this important and neglected disease. Two international consortia this week report the whole genome sequences of the blood flukes Schistosoma mansoni and Schistosoma japonicum, two of the three major pathogens that cause schistosomiasis, also called bilharzia. Schistosomiasis is a 'neglected' tropical disease affecting more than 200 million people in 76 countries. Analyses of the new genome sequences provide insights into the molecular architecture and host interactions of these pathogens, as well as avenues for future development of targeted interventions for this disease. These are the first two flatworm genomes to be sequenced, so they offer new angles on the early events in animal evolution, in particular the determination of body pattern and the development of tissues into organs. Schistosoma mansoni and Schistosoma japonicum are the pathogenic agents that cause the tropical disease schistosomiasis. Here, and in an accompanying paper, the genomes of these two flatworms are sequenced and analysed. The results provide insights into the molecular architecture and host interactions of the flatworms, as well as avenues for future development of targeted interventions for schistosomiasis.

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Trichuris suis therapy in Crohn's disease

2004-12-11

R. W. Summers

Crohn's disease is common in highly industrialised Western countries where helminths are rare and uncommon in less developed areas of the world where most people carry worms. Helminths diminish immune … Crohn's disease is common in highly industrialised Western countries where helminths are rare and uncommon in less developed areas of the world where most people carry worms. Helminths diminish immune responsiveness in naturally colonised humans and reduce inflammation in experimental colitis. Thus exposure to helminths may help prevent or even ameliorate Crohn's disease.The aim of the study was to determine the safety and possible efficacy of the intestinal helminth Trichuris suis in the treatment of patients with active Crohn's disease.Twenty nine patients with active Crohn's disease, defined by a Crohn's disease activity index (CDAI) > or =220 were enrolled in this open label study.All patients ingested 2500 live T suis ova every three weeks for 24 weeks, and disease activity was monitored by CDAI. Remission was defined as a decrease in CDAI to less than 150 while a response was defined as a decrease in CDAI of greater than 100.At week 24, 23 patients (79.3%) responded (decrease in CDAI >100 points or CDAI <150) and 21/29 (72.4%) remitted (CDAI <150). Mean CDAI of responders decreased 177.1 points below baseline. Analysis at week 12 yielded similar results. There were no adverse events.This new therapy may offer a unique, safe, and efficacious alternative for Crohn's disease management. These findings also support the premise that natural exposure to helminths such as T suis affords protection from immunological diseases like Crohn's disease.

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Decreased atopy in children infected with Schistosoma haematobium: a role for parasite-induced interleukin-10

2000-11-01

Anita HJ van den Biggelaar , Ronald van Ree , Laura C. Rodrigues +4 more

Identification of an interleukin (IL)-25–dependent cell population that provides IL-4, IL-5, and IL-13 at the onset of helminth expulsion

2006-04-10

Padraic G. Fallon , Sarah J. Ballantyne , Niamh E. Mangan +6 more

Type 2 immunity, which involves coordinated regulation of innate and adaptive immune responses, can protect against helminth parasite infection, but may lead to allergy and asthma after inappropriate activation. We … Type 2 immunity, which involves coordinated regulation of innate and adaptive immune responses, can protect against helminth parasite infection, but may lead to allergy and asthma after inappropriate activation. We demonstrate that il25−/− mice display inefficient Nippostrongylus brasiliensis expulsion and delayed cytokine production by T helper 2 cells. We further establish a key role for interleukin (IL)-25 in regulating a novel population of IL-4–, IL-5–, IL-13–producing non–B/non–T (NBNT), c-kit+, FcεR1− cells during helminth infection. A deficit in this population in il25−/− mice correlates with inefficient N. brasiliensis expulsion. In contrast, administration of recombinant IL-25 in vivo induces the appearance of NBNT, c-kit+, FcεR1− cells and leads to rapid worm expulsion that is T and B cell independent, but type 2 cytokine dependent. We demonstrate that these IL-25–regulated cells appear rapidly in the draining lymph nodes, implicating them as a source of type 2 cytokines during initiation of worm expulsion.

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Soil-transmitted helminth infections: ascariasis, trichuriasis, and hookworm

2006-05-01

Jeffrey M. Bethony , Simon Brooker , Marco Albonico +4 more

The Neglected Tropical Diseases of Latin America and the Caribbean: A Review of Disease Burden and Distribution and a Roadmap for Control and Elimination

2008-09-23

Peter J. Hotez , María Elena Bottazzi , Carlos Franco‐Paredes +2 more

The neglected tropical diseases (NTDs) represent some of the most common infections of the poorest people living in the Latin American and Caribbean region (LAC). Because they primarily afflict the … The neglected tropical diseases (NTDs) represent some of the most common infections of the poorest people living in the Latin American and Caribbean region (LAC). Because they primarily afflict the disenfranchised poor as well as selected indigenous populations and people of African descent, the NTDs in LAC are largely forgotten diseases even though their collective disease burden may exceed better known conditions such as of HIV/AIDS, tuberculosis, or malaria. Based on their prevalence and healthy life years lost from disability, hookworm infection, other soil-transmitted helminth infections, and Chagas disease are the most important NTDs in LAC, followed by dengue, schistosomiasis, leishmaniasis, trachoma, leprosy, and lymphatic filariasis. On the other hand, for some important NTDs, such as leptospirosis and cysticercosis, complete disease burden estimates are not available. The NTDs in LAC geographically concentrate in 11 different sub-regions, each with a distinctive human and environmental ecology. In the coming years, schistosomiasis could be eliminated in the Caribbean and transmission of lymphatic filariasis and onchocerciasis could be eliminated in Latin America. However, the highest disease burden NTDs, such as Chagas disease, soil-transmitted helminth infections, and hookworm and schistosomiasis co-infections, may first require scale-up of existing resources or the development of new control tools in order to achieve control or elimination. Ultimately, the roadmap for the control and elimination of the more widespread NTDs will require an inter-sectoral approach that bridges public health, social services, and environmental interventions.

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Neglected tropical diseases

2009-12-10

Nicholas Feasey , Mark Wansbrough‐Jones , David Mabey +1 more

The neglected tropical diseases (NTDs) are infectious diseases that principally impact the world's poorest people. They have been neglected for decades, initially as part of a general disregard for the … The neglected tropical diseases (NTDs) are infectious diseases that principally impact the world's poorest people. They have been neglected for decades, initially as part of a general disregard for the developing world, and more recently due to the intensity of focus on HIV/AIDS, tuberculosis and malaria. Primary research and review articles were selected for inclusion using searches of PubMed and our existing collections. There have been recent notable successes in NTD control. Dracunculiasis is approaching eradication. Leprosy and onchocerciasis are in decline. There are ambitious plans to eliminate trachoma and lymphatic filariasis. Investment in NTD control has high rates of economic return. Although there are proven strategies to control several NTDs, these diseases continue to cause a massive burden of morbidity. There is urgent need for more basic and operational research, drug and vaccine development, and greater prioritization by governments and international agencies.

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Helminth parasites – masters of regulation

2004-09-10

Rick M. Maizels , Adam Balic , Natalia Gomez‐Escobar +3 more

Summary: Immune regulation by parasites is a global concept that includes suppression, diversion, and conversion of the host immune response to the benefit of the pathogen. While many microparasites escape … Summary: Immune regulation by parasites is a global concept that includes suppression, diversion, and conversion of the host immune response to the benefit of the pathogen. While many microparasites escape immune attack by antigenic variation or sequestration in specialized niches, helminths appear to thrive in exposed extracellular locations, such as the lymphatics, bloodstream, or gastrointestinal tract. We review here the multiple layers of immunoregulation that have now been discovered in helminth infection and discuss both the cellular and the molecular interactions involved. Key events among the host cell population are dominance of the T‐helper 2 cell (Th2) phenotype and the selective loss of effector activity, against a background of regulatory T cells, alternatively activated macrophages, and Th2‐inducing dendritic cells. Increasingly, there is evidence of important effects on other innate cell types, particularly mast cells and eosinophils. The sum effect of these changes to host reactivity is to create an anti‐inflammatory environment, which is most favorable to parasite survival. We hypothesize therefore that parasites have evolved specific molecular strategies to induce this conducive landscape, and we review the foremost candidate immunomodulators released by helminths, including cytokine homologs, protease inhibitors, and an intriguing set of novel products implicated in immune suppression.

Alternative Activation of Macrophages: An Immunologic Functional Perspective

2008-12-23

Fernando O. Martínez , Laura Helming , Siamon Gordon

Macrophages are innate immune cells with well-established roles in the primary response to pathogens, but also in tissue homeostasis, coordination of the adaptive immune response, inflammation, resolution, and repair. These … Macrophages are innate immune cells with well-established roles in the primary response to pathogens, but also in tissue homeostasis, coordination of the adaptive immune response, inflammation, resolution, and repair. These cells recognize danger signals through receptors capable of inducing specialized activation programs. The classically known macrophage activation is induced by IFN-gamma, which triggers a harsh proinflammatory response that is required to kill intracellular pathogens. Macrophages also undergo alternative activation by IL-4 and IL-13, which trigger a different phenotype that is important for the immune response to parasites. Here we review the cellular sources of these cytokines, receptor signaling pathways, and induced markers and gene signatures. We draw attention to discrepancies found between mouse and human models of alternative activation. The evidence for in vivo alternative activation of macrophages is also analyzed, with nematode infection as prototypic disease. Finally, we revisit the concept of macrophage activation in the context of the immune response.

Reassessment of the cost of chronic helmintic infection: a meta-analysis of disability-related outcomes in endemic schistosomiasis

2005-04-01

Charles H. King , Katherine Dickman , Daniel J. Tisch

Schistosomiasis and water resources development: systematic review, meta-analysis, and estimates of people at risk

2006-06-20

Peter Steinmann , Jennifer Keiser , Robert Bos +2 more

Protective immune mechanisms in helminth infection

2007-11-16

Robert M. Anthony , Laura I. Rutitzky , Joseph F. Urban +2 more

Global numbers of infection and disease burden of soil transmitted helminth infections in 2010

2014-01-01

Rachel L. Pullan , Jennifer L. Smith , Rashmi Jasrasaria +1 more

Quantifying the burden of parasitic diseases in relation to other diseases and injuries requires reliable estimates of prevalence for each disease and an analytic framework within which to estimate attributable … Quantifying the burden of parasitic diseases in relation to other diseases and injuries requires reliable estimates of prevalence for each disease and an analytic framework within which to estimate attributable morbidity and mortality. Here we use data included in the Global Atlas of Helminth Infection to derive new global estimates of numbers infected with intestinal nematodes (soil-transmitted helminths, STH: Ascaris lumbricoides, Trichuris trichiura and the hookworms) and use disability-adjusted life years (DALYs) to estimate disease burden. Prevalence data for 6,091 locations in 118 countries were sourced and used to estimate age-stratified mean prevalence for sub-national administrative units via a combination of model-based geostatistics (for sub-Saharan Africa) and empirical approaches (for all other regions). Geographical variation in infection prevalence within these units was approximated using modelled logit-normal distributions, and numbers of individuals with infection intensities above given thresholds estimated for each species using negative binomial distributions and age-specific worm/egg burden thresholds. Finally, age-stratified prevalence estimates for each level of infection intensity were incorporated into the Global Burden of Disease Study 2010 analytic framework to estimate the global burden of morbidity and mortality associated with each STH infection. Globally, an estimated 438.9 million people (95% Credible Interval (CI), 406.3 - 480.2 million) were infected with hookworm in 2010, 819.0 million (95% CI, 771.7 – 891.6 million) with A. lumbricoides and 464.6 million (95% CI, 429.6 – 508.0 million) with T. trichiura. Of the 4.98 million years lived with disability (YLDs) attributable to STH, 65% were attributable to hookworm, 22% to A. lumbricoides and the remaining 13% to T. trichiura. The vast majority of STH infections (67%) and YLDs (68%) occurred in Asia. When considering YLDs relative to total populations at risk however, the burden distribution varied more considerably within major global regions than between them. Improvements in the cartography of helminth infection, combined with mathematical modelling approaches, have resulted in the most comprehensive contemporary estimates for the public health burden of STH. These numbers form an important benchmark upon which to evaluate future scale-up of major control efforts.

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Strongyloides stercoralis: Global Distribution and Risk Factors

2013-07-11

Fabian Schär , Ulf Trostdorf , Federica Giardina +5 more

The soil-transmitted threadworm, Strongyloides stercoralis, is one of the most neglected among the so-called neglected tropical diseases (NTDs). We reviewed studies of the last 20 years on S. stercoralis's global … The soil-transmitted threadworm, Strongyloides stercoralis, is one of the most neglected among the so-called neglected tropical diseases (NTDs). We reviewed studies of the last 20 years on S. stercoralis's global prevalence in general populations and risk groups.A literature search was performed in PubMed for articles published between January 1989 and October 2011. Articles presenting information on infection prevalence were included. A Bayesian meta-analysis was carried out to obtain country-specific prevalence estimates and to compare disease odds ratios in different risk groups taking into account the sensitivities of the diagnostic methods applied. A total of 354 studies from 78 countries were included for the prevalence calculations, 194 (62.4%) were community-based studies, 121 (34.2%) were hospital-based studies and 39 (11.0%) were studies on refugees and immigrants. World maps with country data are provided. In numerous African, Asian and South-American resource-poor countries, information on S. stercoralis is lacking. The meta-analysis showed an association between HIV-infection/alcoholism and S. stercoralis infection (OR: 2.17 BCI: 1.18-4.01; OR: 6.69; BCI: 1.47-33.8), respectively.Our findings show high infection prevalence rates in the general population in selected countries and geographical regions. S. stercoralis infection is prominent in several risk groups. Adequate information on the prevalence is still lacking from many countries. However, current information underscore that S. stercoralis must not be neglected. Further assessments in socio-economic and ecological settings are needed and integration into global helminth control is warranted.

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Strongyloides stercoralisin the Immunocompromised Population

2004-01-01

Paul B. Keiser , Thomas B. Nutman

SUMMARY Strongyloides stercoralis is an intestinal nematode of humans that infects tens of millions of people worldwide. S. stercoralis is unique among intestinal nematodes in its ability to complete its … SUMMARY Strongyloides stercoralis is an intestinal nematode of humans that infects tens of millions of people worldwide. S. stercoralis is unique among intestinal nematodes in its ability to complete its life cycle within the host through an asexual autoinfective cycle, allowing the infection to persist in the host indefinitely. Under some conditions associated with immunocompromise, this autoinfective cycle can become amplified into a potentially fatal hyperinfection syndrome, characterized by increased numbers of infective filariform larvae in stool and sputum and clinical manifestations of the increased parasite burden and migration, such as gastrointestinal bleeding and respiratory distress. S. stercoralis hyperinfection is often accompanied by sepsis or meningitis with enteric organisms. Glucocorticoid treatment and human T-lymphotropic virus type 1 infection are the two conditions most specifically associated with triggering hyperinfection, but cases have been reported in association with hematologic malignancy, malnutrition, and AIDS. Anthelmintic agents such as ivermectin have been used successfully in treating the hyperinfection syndrome as well as for primary and secondary prevention of hyperinfection in patients whose exposure history and underlying condition put them at increased risk.

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Diagnosis ofStrongyloides stercoralisInfection

2001-10-01

Afzal A. Siddiqui , Steven L. Berk

Strongyloides stercoralis infects 30 million people in 70 countries. Infection usually results in asymptomatic chronic disease of the gut, which can remain undetected for decades. However, in patients receiving long-term … Strongyloides stercoralis infects 30 million people in 70 countries. Infection usually results in asymptomatic chronic disease of the gut, which can remain undetected for decades. However, in patients receiving long-term corticosteroid therapy, hyperinfection can occur, resulting in high mortality rates (up to 87%). Strongyloidiasis is difficult to diagnose because the parasite load is low and the larval output is irregular. Results of a single stool examination by use of conventional techniques fail to detect larvae in up to 70% of cases. Several immunodiagnostic assays have been found ineffective in detecting disseminated infections and show extensive cross-reactivity with hookworms, filariae, and schistosomes. Although it is important to detect latent S. stercoralis infections before administering chemotherapy or before the onset of immunosuppression in patients at risk, a specific and sensitive diagnostic test is lacking. This review describes the clinical manifestations of strongyloidiasis, as well as various diagnostic tests and treatment strategies.

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Rescuing the bottom billion through control of neglected tropical diseases

2009-05-01

Peter J. Hotez , Alan Fenwick , Lorenzo Savioli +1 more

Statistical methods in medical research

1972-11-01

Hyman Menduke

Soil-transmitted helminth infections

2017-09-05

P Jourdan , Poppy H. L. Lamberton , Alan Fenwick +1 more

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Human schistosomiasis

2014-04-01

Daniel G. Colley , Amaya L. Bustinduy , W. Evan Secor +1 more

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Human schistosomiasis

2006-09-01

B. Gryseels , Katja Polman , Jan Clerinx +1 more

Schistosomiasis

2018-08-09

Donald P. McManus , David W. Dunne , Moussa Sacko +3 more

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Schistosomes, liver flukes and Helicobacter pylori.

1994-01-01

Prevention and control of schistosomiasis and soil-transmitted helminthiasis.

2002-01-01

This report contains the recommendations of a WHO Expert Committee convened to consider the prevention and control of schistosomiasis and soil-transmitted helminth infections. Although these infections remain major public health … This report contains the recommendations of a WHO Expert Committee convened to consider the prevention and control of schistosomiasis and soil-transmitted helminth infections. Although these infections remain major public health concerns in many parts of the world, particularly in the poorest developing countries, cost-effective solutions are both available and deliverable. The report reviews the burden of disease, its impact on both health and development, the substantial benefits of treatment, and the safety, efficacy and ease of administration of available anthelminthic drugs. Similarities in the population at risk and in the tools required to combat the problems have prompted moves towards a combined approach to the control of schistosomiasis and soil-transmitted helminthiasis. Such an approach relies largely on epidemiological surveillance, health education, improvements in hygiene and sanitation, and--above all--regular treatment of high-risk groups, particularly school-age children. The report focuses on how these various elements can be achieved, emphasizing the potential of the school system for drug delivery and health education and the opportunities for integration of control activities with existing health programmes. It also stresses that the cost of recommended anthelminthic drugs has now fallen to a level at which it should no longer deter Member States from making treatment widely available in endemic areas. The recommendations of the Expert Committee provide clear and strategic guidance on the implementation of control measures and on ensuring their sustainability.

Knowledge of Intestinal Parasitic Infection and Anemia among Pregnant Women Attending Antenatal Clinic in Ogun State

2024-06-12

A. Bolatito Oluwabiyi , O. Hannah Akanbi , Oluwaseun Ipede

A study was conducted at General Hospital Ijebu Igbo antenatal section to investigate the prevalence of intestinal parasitic infection and anemia in pregnant women. A questionnaire was administered to 42 … A study was conducted at General Hospital Ijebu Igbo antenatal section to investigate the prevalence of intestinal parasitic infection and anemia in pregnant women. A questionnaire was administered to 42 pregnant women who attended the antenatal section of the clinic during the study period. Out of these 42 pregnant women, 18 (42.9%) provided both fecal and blood samples for parasitological and hematological analysis. 50% of the respondents fall within 16-25years age group, while those within 36-45years have the lowest percentage (22.2%). 50% have the knowledge of the helminth infection, out of the 9(50%) that have the knowledge, only 7(77.8%) have the knowledge of how the infection is being transmitted. Of 18 respondents, 13(72%) have the knowledge of anemia, and 5(28%) of them had no prior knowledge of it. The parasitological analysis revealed three intestinal parasite which are Ascaris lumbricoides (22.2%), Enterobius vermicularis (11.11%) and Entamoeba histolytica (5.56%). There were no reported cases of severe anaemic condition in this hospital based study. This suggests that the awareness level of anemia and parasitic infection is moderately high. Therefore, screening for intestinal parasites and deworming of infected pregnant women should be included in antenatal care.

Working to overcome the global impact of neglected tropical diseases : first WHO report on neglected tropical diseases

2010-01-01

D Daumerie , Lorenzo Savioli , D. W. T. Crompton +2 more

Prevention and control of schistosomiasis and soil-transmitted helminthiasis : report of a WHO expert committee

2002-01-01

Soil-transmitted Helminthiasis

Frequency of Intestinal Parasites in Patients Admitted to the Microbiology Laboratory of Siirt Training and Research Hospital

2025-06-25

Leyla Gündüz , Selahattin Aydemir , Zeynep Taş Cengiz +1 more | Turkish Journal of Parasitology

Prevalence of intestinal parasites in school-age children in Turkey: A systematic review and meta-analysis

2025-06-25

Ahmed Galip Halidi , Kemal Yaran , Selahattin Aydemir +2 more | PLoS neglected tropical diseases

Background Intestinal parasites are a major public health problem worldwide, especially in societies with low socioeconomic status and where sanitation rules are not sufficiently emphasized. School-age children are the most … Background Intestinal parasites are a major public health problem worldwide, especially in societies with low socioeconomic status and where sanitation rules are not sufficiently emphasized. School-age children are the most affected group in these societies. In light of the literature data, the intestinal parasites detected in school-age children and the geographical and socioeconomic structure of Turkey are evaluated together. The study hypothesizes that the parasite prevalence in school-age children is high, and there is substantial socioeconomic and geographical variation in species-specific prevalence. It is aimed to determine the pooled prevalence of intestinal parasite infections in school-age children in Turkey, identify the common parasite species, and compare the prevalence in different geographical regions of Turkey. Methods The Web of Science, PubMed, Scopus, and TR index databases were searched to access published articles reporting the presence of intestinal parasites among school-age children in Turkey. The prevalence of intestinal parasites was calculated using a random effects model. Subgroup analyses were performed according to the parasite species and geographical regions of Turkey. Also, year-based meta-regression analyses were conducted. Results A total of 204.754 samples from 99 articles were included in the analysis. The pooled prevalence of intestinal parasites was 29%, with high heterogeneity (I 2 = 99.88%, P < 0.001). The subgroup analysis revealed that the Southeastern Anatolia is the region with higher prevalence of intestinal parasites among school-age children, with a rate of 41% (I 2 = 99.44%, P < 0.001). Subgroup analysis for parasite species revealed that G. intestinalis/duedonalis/labmblia (11%; 95% CI: 9%-13%, I 2 = 99.85) was the most frequently detected parasite in school-age children, followed by Blastocystis spp., Enterobius vermicularis, Entamoeba coli, Ascaris lumbricoides and Entamoeba histolytica/dispar. Conclusion The prevalence of intestinal parasitic infections (IPI) among school-age children in Turkey is particularly high in Southeastern Anatolia, the Mediterranean, and Eastern Anatolia. Socioeconomic conditions, education, and geography are the main factors that affect this situation. It is crucial for school-age children and their parents to receive education on the transmission mechanisms of intestinal parasitic infections (IPIs) and strategies for their prevention. Furthermore, it is essential for local governments and public authorities to upgrade infrastructure to ensure that drinking water and food are not contaminated by polluted water sources.

Closing the diagnostic gap in male genital schistosomiasis (MGS): current detection tools and novel strategies

2025-06-24

Bronwyn Neufeld , Sergio España Cueto , Lisette van Lieshout +7 more | Parasitology

La macroematuria che non ti aspetti

2025-06-23

Gaia Bossalini , Francesca Gaudenzi , Roberta Sodero +5 more | Medico e Bambino pagine elettroniche

Macrohaematuria and microhematuria may be signs of various diseases. Infectious haematuria often presents with fever and/or dysuria. The paper describes the case of a 14-years-old boy from Mali who was … Macrohaematuria and microhematuria may be signs of various diseases. Infectious haematuria often presents with fever and/or dysuria. The paper describes the case of a 14-years-old boy from Mali who was in Italy for five months and presented with gross haematuria and dysuria for three weeks. He was afebrile and denied abdominal symptoms. The physical examination was normal. The blood count showed absolute hypereosinophilia and mild microcytic anaemia. The analysis of the urine showed proteinuria and haemoglobinuria, while the urine culture was negative. Ultrasound of the urinary tract revealed a periurethral microcyst. The search for Plasmodium falciparum (PH) was positive (parasitaemia < 0.1%). Given the haematuria and hypereosinophilia, serological tests were carried out for intestinal parasites, revealing anti-schistosome IgG antibodies positivity. Microscopic analysis of the urinary sediment high-lighted the presence of SH eggs. Dihydroartemisinine-piperaquine and praziquantel were administered. Recent migratory flows and climate change have increased the spread of tropical diseases in Italy. A diagnostic process that integrates anamnesis and epidemiological notions is essential.

Decade‐long persistence of high levels of pyrethroid resistance in Triatoma infestans populations of the Argentine Chaco

2025-06-23

María Sol Gaspe , Marta Victoria Cardinal , Mariano Cáceres +7 more | Medical and Veterinary Entomology

The emergence of insecticide resistance is one of the major challenges vector control programmes face worldwide. For Chagas disease and its main vector Triatoma infestans, pyrethroid-resistant foci have severely compromised … The emergence of insecticide resistance is one of the major challenges vector control programmes face worldwide. For Chagas disease and its main vector Triatoma infestans, pyrethroid-resistant foci have severely compromised vector control and elimination efforts across sections of northern Argentina and Bolivia. We assessed the status and spatiotemporal distribution of pyrethroid resistance in T. infestans populations in Castelli (Argentine Chaco), where it had reached record levels, and tested whether the village-level prevalence of house infestation was associated with pyrethroid resistance. We also monitored the infestation and pyrethroid resistance status of a reinfested (index) house in an adjacent municipality (Pampa del Indio) under sustained triatomine surveillance and control. Eighty-three georeferenced populations of T. infestans collected in 13 villages over 2018-2024 were tested for susceptibility to deltamethrin by discriminant-dose assays. Widespread pyrethroid resistance occurred in 12 villages; 45% of the tested bug populations had very low mortality (<45%). Pyrethroid resistance levels were spatially heterogeneous between and within villages, were negatively associated with house infestation at the village level and reached record resistance ratios (RR50 > 2400). Pampa del Indio's index house remained persistently infested with high resistance levels despite pyrethroid applications and other interventions (i.e., repeated control failures) over a 7-year period. Castelli's highly resistant focus has persisted for >10 year despite the near absence of government-sponsored pyrethroid applications. Alternative insecticides effective against pyrethroid-resistant T. infestans populations are urgently needed to suppress them and curtail their propagation. Sustainable triatomine control in this high-risk scenario requires an integrated vector management framework including housing and peridomestic modifications combined with community-based triatomine surveillance.

Genetic diversity within Strongyloides fuelleborni: Mitochondrial genome analysis reveals a clear African and Asian division

2025-06-23

Travis Richins , Sarah G. H. Sapp , Alexandra Juhász +4 more | Parasitology

Genetic Characterization of Schistosoma Species from Goats in Pakistan Using the 28S rDNA Region

2025-06-23

Muhammad Asim Khan , Kiran Afshan , Sabika Firasat +3 more | Indian Journal of Microbiology

“Female Genital Schistosomiasis: Translational Challenges and Opportunities”: Outputs and actions from a consultative, collaborative and translational workshop.

2025-06-23

Peter S Wasson , Maia Kavanagh Williamson , Amelia Hallas-Potts +7 more | Parasitology

Rare case of pulmonary paragonimiasis in Jubail city

2025-06-23

Salah Ahmed Ali , Randa Ahmed , Marwa Talaat El Deeb +3 more | Egyptian Journal of Bronchology

Abstract Introduction Paragonimiasis, a parasitic infection caused by Paragonimus westermani , is a rare but important differential diagnosis in patients presenting with cavitating lung lesions, especially those from endemic regions. … Abstract Introduction Paragonimiasis, a parasitic infection caused by Paragonimus westermani , is a rare but important differential diagnosis in patients presenting with cavitating lung lesions, especially those from endemic regions. Extrapulmonary involvement is uncommon and can pose significant diagnostic challenges. Patient information A 41-year-old Filipino man, working as a driver, came to the emergency department with a 4-week history of shortness of breath, productive cough with yellowish sputum, fever, and body aches. He had a known history of poorly controlled type 2 diabetes for 4 years and was a heavy smoker. Clinical findings On examination, the patient appeared unwell with signs of hypoxemia and fever. Diagnostic assessment Initial investigation for multiple caviraty lesion were done like sputum for AFB. Given his background and travel history from an endemic area, parasitic infection was considered. A wet mount examination of fresh sputum revealed P. westermani ova, confirming the diagnosis. MRI scans of the brain and abdomen were unremarkable, but pelvic MRI revealed a scrotal abscess. The patient underwent surgical drainage of the abscess along with a left inguinal orchidectomy. Interestingly, Paragonimus ova were found in the abscess fluid, but no bacteria were cultured. Histopathology of the excised tissue showed intense inflammation involving the epididymis, spermatic cord, and surrounding tissues, with atrophic changes in the testicle—though no ova were seen in the histological samples. Therapeutic intervention He was started on praziquantel, the standard antiparasitic treatment, and recovered well following surgery. Follow-up and outcomes The patient showed noticeable clinical improvement after treatment. Conclusion This case underscores the importance of considering parasitic infections like P. westermani in patients with cavitary lung disease, particularly when typical causes are excluded. It also illustrates that extrapulmonary manifestations, though rare, can occur and may require surgical intervention. A high index of suspicion, especially in patients from endemic areas, can lead to timely diagnosis and effective management. This is the first case report of pulmonary paragonimiasis in Jubail and complicated by scrotal abscess worldwide.

INTESTINAL PARASITES AND ANAEMIA AMONGST ADULT PATIENTS ATTENDING A TERTIARY HOSPITAL IN CALABAR, NIGERIA

2025-06-22

Emmanuel Offiong Effanga , Edema Enogiomwan Imalele , O E Okon | medRxiv (Cold Spring Harbor Laboratory)

A study was carried out to determine the prevalence of intestinal parasitic infestations and anaemia among adult outpatients (aged 21 to 50 years) attending the University of Calabar Teaching Hospital, … A study was carried out to determine the prevalence of intestinal parasitic infestations and anaemia among adult outpatients (aged 21 to 50 years) attending the University of Calabar Teaching Hospital, Calabar, Cross River State, Nigeria. Anaemic status was determined by haematocrit, while parasitic infestation was determined using flotation and direct smear techniques. 42% of the anaemic patients were positive for intestinal parasites, while only 4% of the non-anaemic patients were positive for intestinal parasites. This was highly significant (chi-squared = 40.768, p < 0.00001). Hookworm was the most common parasite infecting patients (14%), followed by Entamoeba histolytica (9%), Ascaris lumbricoides (5%), Trichuris trichiura (3.5%), and Balantidium coli (1%). Infections with hookworm were of moderate to high intensity. 26.6% of males were infected compared to 18.7% of females, though this difference was not statistically significant (chi-squared = 1.758, p = 0.185). Polyparasitism was more common in males than females, and all cases of polyparasitism occurred in anaemic patients. The age group 31 to 40 years had the highest infection rate (24.3%). The study demonstrated a relationship between parasitic infestation and altered haematological indices. The results also highlight that parasite control programs targeted at school-aged children should be extended to people of all age groups. Anaemic conditions were worsened by parasite infestations. Keywords: Anaemia, Intestinal parasites, Hospital, Calabar

Experimental Models and Their Applicability in Inflammation Studies: Rodents, Fish, and Nematodes

2025-06-22

Alessandra Bittencourt de Lemos , Jaluza Luana Carvalho de Queiroz , Bruna Leal Lima Maciel +1 more | International Journal of Molecular Sciences

Experimental models have been widely used to study the mechanisms of inflammation due to their genetic and physiological relevance to humans. These models include rodents (rats and mice), zebrafish, and … Experimental models have been widely used to study the mechanisms of inflammation due to their genetic and physiological relevance to humans. These models include rodents (rats and mice), zebrafish, and nematodes (C. elegans). Considering the similarities and divergences between experimental models and the human organism, this narrative review aimed to compare and discuss their applicability in inflammation studies. Rodents, in particular, share significant similarities with humans across approximately 85% of their genome, making them ideal for investigating complex diseases and inflammatory responses. Zebrafish also stand out for showing high conservation of the immune system compared to humans, being useful for studies of adaptive and innate inflammation. Despite not having adaptive immunity, Caenorhabditis elegans is a robust model for understanding innate immune responses, especially in studies involving host–pathogen interactions. These organisms allow us to efficiently investigate the acute and chronic phases of inflammation, offering an accessible platform to study complex biological processes that are unfeasible in humans due to ethical and financial constraints. Thus, the use of these models has been essential for inflammation research. However, the use of each one will depend on the research question and hypothesis raised.

Evidence for persistent multilocus genotypes of Biomphalaria pfeifferi in a natural population in Kenya, with implications for transmission of Schistosoma mansoni

2025-06-21

Noel A Oduor , Daniel Kariuki , Gerald M. Mkoji +5 more | Parasites & Vectors

Abstract Background Biomphalaria pfeifferi , a predominantly self-fertilizing freshwater snail, is the world’s most important intermediate host for Schistosoma mansoni , one of the causative agents of schistosomiasis, a neglected … Abstract Background Biomphalaria pfeifferi , a predominantly self-fertilizing freshwater snail, is the world’s most important intermediate host for Schistosoma mansoni , one of the causative agents of schistosomiasis, a neglected tropical disease affecting millions of people in sub-Saharan Africa. We sought to determine whether we could identify distinct and persistent lineages of B. pfeifferi within a natural stream habitat in western Kenya, indicative of their asexual descent. We also sought to determine whether infections by S. mansoni or other trematodes were associated with particular lineages. Methodology Utilizing 14 microsatellite markers in a multiplex polymerase chain reaction (PCR) format, we genotyped 502 B. pfeifferi collected in six bimonthly (every other month) sampling times from the same locality in a single habitat (Asao Stream, western Kenya). Snails were isolated and screened for infection with S. mansoni and other trematodes using the shedding method followed by microscopical examination of any cercariae found. Results We identified 26 multilocus genotypes (MLGs), that were present at two or more sampling times. Four MLGs persisted across the entire 10-month sampling period, one of which was represented by 17 individuals. These persistent lineages harbored a variety of trematode species, with S. mansoni being the most common. The persistent MLGs were more likely to have trematode infections than those found only at a single sampling time. Low genetic differentiation was observed between November and March (fixation index among subpopulations [F ST ] = 0.019; p = < 0.05). The highest genetic differentiation was observed between July and March (F ST = 0.372; p = < 0.001). Analysis of molecular variance (AMOVA) showed higher variation among individuals within sampling times (58%) than within individuals (33%), and a smaller variation (8%) was found among sampling times. Conclusions By identifying the presence of persistent MLGs and their associations with trematode transmission, this study highlights the importance of considering B. pfeifferi MLGs, some of which could be resistant to infection, when developing strategies to control schistosomiasis transmission within Asao Stream and similar ecosystems across sub-Saharan Africa. Graphical Abstract

Gastroduodenal Strongyloidiasis Diagnosed during Iron Deficiency Anemia Workup

2025-06-20

Malek Kreidieh , Neville Mobarakai , Sherif Andrawes +4 more | Case Reports in Gastroenterology

Introduction: The Strongyloidae family includes at least fifty species of intestinal nematode worms, and Strongyloides stercoralis is the most prevalent one among humans. As a result of this parasite’s complex … Introduction: The Strongyloidae family includes at least fifty species of intestinal nematode worms, and Strongyloides stercoralis is the most prevalent one among humans. As a result of this parasite’s complex lifecycle, it can either remain localized in the intestines or disseminate to different organs throughout the body, culminating in hyperinfection in case of immunosuppression. Strongyloidiasis is rarely encountered in the USA, and an associated gastric involvement is uncommon. Case Presentation: In this case report, we describe the case of an asymptomatic and immunocompetent Liberian patient with gastroduodenal strongyloidiasis whose diagnosis was based on histologic findings during endoscopic evaluation for iron deficiency anemia. Conclusion: This case sheds light on the importance of suspecting the diagnosis of disseminated strongyloidiasis in high-risk individuals with iron deficiency anemia in combination with peripheral eosinophilia.

Community views on mass drug administration for soil-transmitted helminths: a qualitative evidence synthesis

2025-06-20

Tilly Fox , Swastika Shrestha , Rebecca Kuehn +1 more | Cochrane library

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Abdominal imaging findings in tropical endemic diseases: a pictorial review

2025-06-19

Bruna Kozlowski Andreucci , Júlia de Toledo-Mendes , Nathalie Dias +6 more | Abdominal Radiology

PARASITOSES INTESTINAIS: MÉTODOS DE DIAGNÓSTICO E INTERPRETAÇÃO DE RESULTADOS

2025-06-19

André Moreira de Araújo | Revista fisio&terapia.

As parasitoses intestinais representam um importante desafio em saúde pública, exigindo métodos diagnósticos precisos e uma interpretação criteriosa dos resultados para garantir um tratamento eficaz e o controle adequado das … As parasitoses intestinais representam um importante desafio em saúde pública, exigindo métodos diagnósticos precisos e uma interpretação criteriosa dos resultados para garantir um tratamento eficaz e o controle adequado das infecções. O objetivo geral abordar sobre a parasitose intestinal bem como sua epidemiologia, enquanto os objetivos específicos foram discorrer sobre tipos de métodos de diagnóstico e salientar sobre a interpretação de resultados. O presente trabalho trata-se de uma revisão bibliográfica buscado em bases de dados online com o tempo recorte de 10 anos. As parasitoses intestinais seguem como um desafio relevante à saúde pública, especialmente em países em desenvolvimento, onde condições socioeconômicas desfavoráveis e infraestrutura sanitária precária favorecem sua persistência. A elevada prevalência em grupos vulneráveis demanda estratégias diagnósticas eficazes, que combinem métodos laboratoriais desde técnicas tradicionais de microscopia até tecnologias avançadas, como testes moleculares e inteligência artificial com uma interpretação clínica criteriosa. Limitações como baixa sensibilidade, influência do estágio parasitário e dificuldades na conservação das amostras exigem preparo técnico e análise crítica dos profissionais envolvidos. Assim, a integração entre diagnóstico laboratorial, dados clínico- epidemiológicos e atualização constante dos protocolos é essencial para aumentar a precisão diagnóstica, orientar o tratamento adequado e fortalecer o controle das parasitoses no âmbito coletivo.

Soil transmitted helminths infections in a rural community

2025-06-18

Fullaila O Aliyu , Taofeeqa Olamide Abioye , Mariam Abdulbaki +1 more | Journal of Health Science Research

Objectives Soil-transmitted helminths (STHs) are a type of neglected tropical disease that are responsible for the majority of infections worldwide. The most common STHs are Ascaris lumbricoides , hookworm, S. … Objectives Soil-transmitted helminths (STHs) are a type of neglected tropical disease that are responsible for the majority of infections worldwide. The most common STHs are Ascaris lumbricoides , hookworm, S. stercoralis, and Trichuris trichiura .The aim of the study was to determine the prevalence of STHs in the Agbeyangi community and its associated risk factors. Material and Methods The study is a cross-sectional, community-based descriptive study. Total sampling of consenting participants was done in the community. The research was carried out between June to August of 2023. A validated self-administered questionnaire was used to capture information on socio-demographics. A fecal sample was collected in a test tube after obtaining consent from the parents/guardians, and samples were de-identified and coded. The coded samples were taken to the laboratory on the same day. Helminthes ova were quantitatively determined on slides per sample using the number of eggs per gram (epg) of feces. In order to calculate the amount of epg of feces, the number of helminth eggs was counted and multiplied by 24. Of these, 20% were chosen at random and read once more as a quality control measure and to verify the consistency of the outcome. Results Of the 500 respondents, those in the age range of 18-23 years had the highest response (161, 32.2%), followed by children between the ages 0-5 (137, 27.4%). Males were more prevalent (255, 51.0%) than females (245, 49.0%). The prevalence of STH was 13.2%. Hookworm (27, 40.91%) was the most prevalent species, followed by Entamoeba histolytica (19, 28.79%), the least being S. stercoralis (8, 12.12%). Risk factors for STH infection included the age range of 12-17 years, not wearing shoes, lack of awareness, lack of hand washing, and sources of drinking water (p<0.05). Conclusion Hookworm was the most common helminth infection in the community. However, STH was deemed to be low in the study area. Infection rates were considerably influenced by elements like age group, footwear use, awareness, and handwashing practices.

Case 17-2025: A 61-Year-Old Man with Respiratory Failure and Shock after Kidney Transplantation

2025-06-18

Camille N. Kotton , Rory L. Cochran , Alan M. Sanders +2 more | New England Journal of Medicine

Prevalence of Intestinal Schistosomiasis in Donkeys (Equus asinus) in the Region of Tillabéri, Niger

2025-06-18

Maman Manzo Lawaly , ADAMOU HAMADOU Moctar , KARIMOU HAROUNA Boureima | Journal of Applied Life Sciences International

Aims: to estimate the prevalence of intestinal schistosomiasis in donkeys selected from five different localities of the district of Tillabéri. Study Design: This is a cross-sectional study. Place and Duration … Aims: to estimate the prevalence of intestinal schistosomiasis in donkeys selected from five different localities of the district of Tillabéri. Study Design: This is a cross-sectional study. Place and Duration of Study: District of Tillabéri, Niger republic, from February to April 2023. Methodology: We randomly selected 200 donkeys from five different localities of the district of Tillabéri. Freshly collected feces were passed for coprological examination in order to identify parasitic eggs using the standard sedimentation technique. Results: The results show an overall prevalence of Schistosoma infection of 16%. The highest prevalence was recorded from the samples collected at the site of Day (35%). According to the species of schistosomes present in all the examined feces, four species of schistosoma were identified: Schistosoma bovis (43.75%), Schistosoma mensoni (28.15%), Schistosoma haematobium (24.82%) and Schistosoma intercalatum (3.13%). Conclusion: Findings demonstrated that intestinal schistosomiasis is prevalent in donkeys in the study areas. As a result, large-scale studies in other localities and regions of the country are now clearly needed, to better appreciate the burden of the parasitic infections for proper development of new strategic control program for donkey gastrointestinal helminths in the region of Tillabéri.

Case Report: Uncommon presentation of Schistosoma haematobium infection in a migrant patient: diagnostic and therapeutic challenges

2025-06-17

Francesca Carraturo , Maria Escolino , Assunta Russo +7 more | Frontiers in Medicine

Schistosomiasis is a parasitic infection prevalent mainly in tropical and subtropical countries. We report a case of urinary infection caused by Schistosoma haematobium in a 16 years-old boy from Mali … Schistosomiasis is a parasitic infection prevalent mainly in tropical and subtropical countries. We report a case of urinary infection caused by Schistosoma haematobium in a 16 years-old boy from Mali presented to our Institution with a one-month history of gross hematuria. The physical examination revealed an apparently healthy patient with soft abdomen, treatable, but painful to palpation and otherwise no other significant symptoms. The blood tests were within normal range except for eosinophilia. Urinary ultrasound revealed mild bilateral renal pelvis dilation, and distended bladder with thickened walls and multiple papillomatous growths (up to 31 mm in diameter). Cystoscopy confirmed multiple widespread mucosal lesions, and histology revealed severe eosinophilic cystitis with numerous parasitic eggs, observed, also, in parasitological urine examination, confirming the diagnosis of S. haematobium disease. The patient was diagnosed with schistosomiasis-related cystitis and treated with Praziquantel. At 2 months post-treatment follow-up urine microscope and eosinophil count were normalized and bladder wall irregularities and focal thickenings of variable size (from 3 to 11 mm) were documented. This case highlights the importance of considering hematuria and urinary bladder lesions in patients from areas where Schistosoma spp. is endemic as a strong indicator of parasitosis. Promptly initiating therapy can help prevent potential severe and less manageable consequences.

Assessment of a rapid immunochromatographic test as potential tool for strongyloidiasis diagnosis using samples from an endemic area in Brazil

2025-06-17

Henrique Tomaz Gonzaga , Vanessa da Silva Ribeiro , Rahmah Noordin +1 more | Diagnostic Microbiology and Infectious Disease

Rapid identification of Biomphalaria spp. and diagnosis of Schistosoma mansoni infestation using MALDI-TOF mass spectrometry

2025-06-17

Diara Sy , Lionel Alméras , Adama Zan Diarra +7 more | bioRxiv (Cold Spring Harbor Laboratory)

This study explores the use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify and differentiate Biomphalaria snails infected with the parasite S. mansoni, which causes schistosomiasis. The … This study explores the use of Matrix-Assisted Laser Desorption/Ionization Time-of-Flight mass spectrometry (MALDI-TOF MS) to identify and differentiate Biomphalaria snails infected with the parasite S. mansoni, which causes schistosomiasis. The study was conducted on two snail species, Biomphalaria pfeifferi (collected in the field in Senegal) and Biomphalaria glabrata (a laboratory strain). The snails were infected in the laboratory with S. mansoni miracidia, and their infection was confirmed by cercariae emission tests and quantitative PCR. MALDI-TOF MS was then used to analyse proteins from infected and uninfected snails to identify spectral differences. Based on protein profiles, the results of MALDI-TOF mass spectrometry made it possible to accurately differentiate between S. mansoni-infected snails and uninfected snails. An increase in the number of peaks detected and their intensity was observed for the spectra of S. mansoni-infected snails compared to uninfected snails. The application of principal component analysis to these mass spectrometry profiles confirmed the discrimination between the two groups according to their infection status. In addition, specific discriminating peaks were identified for each snail species, allowing for the distinction of infected from uninfected snails. The present study revealed, for the first time, that MALDI-TOF MS appears to be a rapid, reliable, and specific tool for the diagnosis of schistosomiasis in snails, offering promising prospects for the surveillance and control of this disease in endemic areas. However, further work is needed to establish a MALDI-TOF MS reference spectra database specific to Schistosoma parasites and to standardise sample collection, storage, and preparation in order to apply this technique in the field.

Expression of interleukin-4 in schistosomiasis is influenced by age

2025-06-17

Tresford Lwanga , Lweendo Muchaili , Gift C. Chama +6 more | PLoS neglected tropical diseases

Background Schistosomiasis, a Neglected Tropical Disease (NTD), remains a significant public health issue, particularly in sub-Saharan Africa. Despite various interventions, the disease persists, with a considerable burden on affected populations. … Background Schistosomiasis, a Neglected Tropical Disease (NTD), remains a significant public health issue, particularly in sub-Saharan Africa. Despite various interventions, the disease persists, with a considerable burden on affected populations. This study aimed to characterize the hematological and immunological profiles associated with Schistosoma infection in pediatric and adult populations in Mulobezi district of Zambia. Methods This was a cross-sectional study, which included participants aged 5–55 years, carried out in Mulobezi District in the Western Province of Zambia. The sample size was 143, participants were stratified into children (<15 years) and adults (≥15 years). Schistosomiasis diagnosis was confirmed through urine microscopy using filtration methods, while full blood count and cytokine (IL-4, IL-10) analysis were performed on blood samples. A Multivariate logistic regression was used to identify factors independently associated with infection. Statistical analyses were conducted using two-sided tests to assess the significance of the observed differences between groups. Results Out of the 143 participants, 56 (39.2%) had schistosomiasis. In adjusted models, IL-4 showed age-dependent associations: significant in adults (AOR: 1.007, 95% CI: 1.003-1.012, p = 0.001) but not children (AOR: 1.001, 95% CI: 0.999-1.003, p = 0.072). Lymphocyte counts were elevated in both children (AOR: 1.94, 95% CI: 1.07-3.54, p = 0.029) and adults (AOR: 2.96, 95% CI: 1.19-7.36, p = 0.020). Eosinophils (children: AOR: 13.94, 95% CI: 0.24-811.21, p = 0.204; adults: AOR: 12.27, 95% CI: 0.73-207.13, p = 0.082) and IL-10 lost significance after adjustment. Conclusion This study highlights IL-4 and lymphocyte counts as potential immunomarkers for schistosomiasis infection. The age-specific IL-4 association suggests differential immune activation patterns, while persistent lymphocyte elevation across both groups indicates sustained adaptive immune engagement.

Survey of some intestinal parasites infecting children and their mothers in Haro Health Center, Southwest Ethiopia

2025-06-16

Endalew Zemene , Keiruzaman Abdi , Abdurezak Aman +4 more | Journal of Parasitic Diseases

Estimation and prediction on the economic burden of schistosomiasis in 25 endemic countries

2025-06-16

Xinguang Chen , Qin Li , Robert Bergquist +7 more | Infectious Diseases of Poverty

Abstract Background Schistosomiasis is a neglected tropical disease, primarily prevalent in tropical and subtropical regions. It imposes a significant health and economic burden in low- and middle-income countries, but a … Abstract Background Schistosomiasis is a neglected tropical disease, primarily prevalent in tropical and subtropical regions. It imposes a significant health and economic burden in low- and middle-income countries, but a study of its comprehensive economic impact of the disease at the global level has not been carried out. As this is essential for evidence-based decision-making, this study aims to estimate the macroeconomic burden of schistosomiasis in 25 endemic countries. Methods We used a health-augmented macroeconomic (HAM) model, as well as observed data from 2010 to 2021 and projected data from 2022 to 2050, to model gross domestic product (GDP) under two scenarios: with and without schistosomiasis. The data were obtained from the Global Burden of Disease Study 2021 (GBD 2021), the World Bank database, the International Monetary Fund (IMF) database, the International Labour Organization (ILO) database, the United Nations Population Division's World Population Prospects 2022 database, the Barro-Lee Educational Attainment dataset, the Penn World Table (PWT) database, and relevant literature. The economic burden was quantified as the difference in GDP between these two scenarios. The HAM model considered: (i) the impact of schistosomiasis mortality and morbidity on labor supply; (ii) age and gender differences in education and work experience among schistosomiasis patients; and (iii) the impact of schistosomiasis treatment costs on physical capital accumulation. To be able to compare the purchasing power of different countries, we used international dollars (INT$), a hypothetical currency unit based on purchasing power parity. Results We estimated the macroeconomic burden of schistosomiasis in 25 schistosomiasis endemic countries was INT$ 49,504 million [uncertainty interval (UI): 48,668–50,339] for the study period, using a 3% discount rate in the main analysis. The result implies that the economic burden of schistosomiasis across these 25 countries during study period is equivalent to 0.0174% (UI: 0.0171–0.0177) of total GDP. Among all schistosomiasis-endemic countries included, Egypt had the largest absolute economic burden (INT$ 11,400 million, UI: 11,221–11,578), followed by Brazil (INT$ 9779 million, UI: 9717–9841) and South Africa (INT$ 6744 million, UI: 6676–6811). Conclusions The global economic burden of schistosomiasis remains substantial and is inequitably distributed among countries and regions. Our study highlights the need for increased investment and global collaborative efforts to control schistosomiasis and its associated health and economic burdens. By advancing the elimination of schistosomiasis, substantial economic returns can be achieved. Graphical Abstract

Cross sectional assessment of feasibility and acceptability in screening for female genital schistosomiasis (FGS) in two clinical settings in east province, Cameroon

2025-06-16

Sandrine Nyotue , Laura Ciaffi , Aimé Assigui +5 more | Parasitology

Marginal cytokine modulation by Schistosoma mansoni soluble egg antigen in SARS-CoV-2-infected K18-hACE2 mice

2025-06-16

Yi Mu , Kexin Yan , Donald P. McManus +5 more | Folia Parasitologica

Modelling the evolution of female genital schistosomiasis among female children with untreated urinary schistosomiasis in Nigeria

2025-06-16

Ronke Dorcas Olorunfemi , Emmanuel A. Bakare , Uwem Friday Ekpo +7 more | Modeling Earth Systems and Environment

The characteristics of men who have sex with men withEnterobius vermicularis(threadworms): a systematic review

2025-06-15

Aleks Modlinski , Sarah Lancaster , Lucy Rabuszko +2 more | Frontline Gastroenterology

Objectives Enterobius vermicularis (threadworms) is a parasitic enteric helminth causing anal pruritus. This systematic review aimed to explore demographic, behavioural and biological characteristics seen in men who have sex with … Objectives Enterobius vermicularis (threadworms) is a parasitic enteric helminth causing anal pruritus. This systematic review aimed to explore demographic, behavioural and biological characteristics seen in men who have sex with men (MSM) with E. vermicularis . Methods Four databases (OVID, CINAHL, Web of Science and PubMed) were searched in January 2025. Articles that included MSM diagnosed with E. vermicularis and written in English were included. Following removal of duplicates, citation and abstract review, two independent researchers screened full texts for eligible articles and performed a risk of bias assessment using Joanna Briggs Institute critical appraisal tools. Data were synthesised narratively and the protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO ID: CRD42024597731). Results 11 articles were included in this review from the UK (n=4), the USA (n=3), Iraq (n=1), South Africa (n=1), Australia (n=1) and Cuba (n=1), which included 33 MSM with E. vermicularis published between 1972 and 2024. This review highlighted demographic (young age (median 27 years), living with HIV), behavioural (oral sex, oral-anal sex, anal sex, fisting, multiple/non-regular sexual partners, sex toys, group sex, recreational drug use) and coinfection ( Neisseria gonorrhoeae, Treponema pallidum , hepatitis A, human papillomavirus, recurrent urethritis, Giardia duodenalis, Entamoeba histolytica, Endolimax nana, Iodamoeba buetschlii, Dientamoeba fragilis, Entamoeba coli, intestinal spirochaetosis) characteristics seen in MSM with E. vermicularis . Conclusion Although limited, this review provides some useful insights into the possible sexual transmission of E. vermicularis in MSM for future public health control strategies, clinical guidelines and research. PROSPERO registration number CRD42024597731.

Combining country indicators and individual variables to predict soil-transmitted helminth infections among migrant populations: A case study from southern Italy

2025-06-13

Jana Purkiss , Paola Pepe , Naím Alex Karol Poplawski +4 more | PLoS neglected tropical diseases

An increase in global migration towards developed countries along with climate change has led to the occurrence of Neglected Tropical Diseases (NTDs) in otherwise non-endemic countries. In this paper we … An increase in global migration towards developed countries along with climate change has led to the occurrence of Neglected Tropical Diseases (NTDs) in otherwise non-endemic countries. In this paper we focus on Soil Transmitted Helminth (STH) infections which disproportionately affect people living in poverty in tropical regions. To reduce the threat of STHs in migrant populations living in non-endemic countries, diagnosis and treatment are paramount but also present logistical challenges. This study investigates how statistical modelling can be used to assist the identification of individuals infected with STHs. Specifically, we show how to combine individual variables (e.g., age, sex and time in Italy) with publicly available country indicators (Human Development Index, Multidimensional Poverty Index and Inequality-adjusted Human Development Index) which describe development in the migrant’s country of origin. We combine these indices and their factors in binomial mixed-effects models which can be used to predict the status of STH infections in migrant populations. By presenting a case study on migrants in southern Italy, we assess the relative importance of the individual-level variables and country-level indicators in enhancing the predictive power of the models. The results show that the country-level indices play a more important role but also highlight that individual data can help improve the model performance when combined with the former. To the best of our knowledge this is the first study investigating using country-level indicators to predict parasite infection status of migrants. Our study indicates that statistical models can play an important role in reducing the resources required to identify migrants requiring anthelmintic treatment against STHs and help to make statistically informed decisions.

Microsampling with dried blood spots and mass spectrometry enables PK/PD profiling of responses to praziquantel in a Schistosoma haematobium–exposed Zimbabwean population

2025-06-13

David Twesigomwe , Grace Zdesenko , Takafira Mduluza +3 more | Pharmacogenetics and Genomics

Introduction Praziquantel (PZQ) is commonly used to treat schistosomiasis; however, there is considerable interindividual variability in its efficacy, partly because of genetic variation. Data on this relationship is scarce across … Introduction Praziquantel (PZQ) is commonly used to treat schistosomiasis; however, there is considerable interindividual variability in its efficacy, partly because of genetic variation. Data on this relationship is scarce across Africa – where schistosomiasis is prevalent. This study aimed to investigate the pharmacokinetic/pharmacodynamic and pharmacogenetic relationship between PZQ and its metabolites in a Zimbabwean population infected with Schistosoma haematobium by leveraging dried blood spots (DBS) and mass spectrometry (MS). Methods DBS were obtained from 38 Zimbabwean participants on PZQ treatment at four-time points (0.5, 1.5, 2.5, and 4 h). We compared two extraction methods for recovering PZQ and its metabolites from the DBS cards and performed MS analysis to determine the concentrations. A random forest model was used to determine whether CYP1A2 , CYP2C9 , CYP2C19 , CYP2D6 , CYP3A4 , and CYP3A5 known variants were predictive of PZQ efficacy. The relationships between PZQ/metabolite concentration, metabolite ratio, and drug exposure with genotype were determined using a one-way analysis of variance. Results An acetonitrile and water (4 : 1) mixture was determined to be optimal for recovering PZQ and its metabolites from the DBS cards. Subsequent MS analysis identified PZQ and six metabolite compounds – including phase 1 metabolites (–2H)-O-PZQ, O2-PZQ, and 4-OH-PZQ. Pooled MS sampling was comparable to individual MS sampling for determining pharmacokinetic profiles at the 2.5 and 4-h time points. The (–2H)-O-PZQ and O2-PZQ metabolites had significantly higher concentrations in participants with CYP2C9*1/*9 and *9/*9 versus those with CYP2C9*1/*1 . CYP1A2 rs2069514-A (formerly *1C ) and rs762551-A ( CYP1A2*30 ; formerly *1F ) were observed to alter PZQ pharmacokinetic profiles; however, differences in analyte concentrations across the corresponding genotypes were NS. Conclusion We show that low-cost microsampling using DBS and MS is feasible for detecting and quantifying PZQ and its metabolites. Furthermore, our pharmacogenetics analysis elucidates the impact of known cytochrome P450 variants on PZQ drug response in an African setting.

Does schistosome infection affect behavior through the gut-brain axis?

2025-06-12

Leigh Combrink , Johannie M. Spaan , Audrey Perret +7 more | PLoS neglected tropical diseases

Parasitic helminths infect over 2 billion people, primarily those living in poverty. Helminth infections typically establish in early childhood and persist through critical periods of growth and development, leading to … Parasitic helminths infect over 2 billion people, primarily those living in poverty. Helminth infections typically establish in early childhood and persist through critical periods of growth and development, leading to cognitive deficits and/or behavioral changes. These deficits could result from the helminths themselves or due to dysbiosis of the gut microbiota and its influence on the gut-brain axis. Using two cohorts of 3-week-old female mice, we measured levels of anxiety, fear, compulsion, spatial learning, and spatial memory, between schistosome-infected and sham-exposed mice. Additionally, we compared their fecal microbiomes using 16S rRNA gene sequencing at two time points during the chronic stage of infection. Schistosome-infected mice showed higher levels of anxiety in the open field test, reduced spatial learning in the Morris water maze task, and enhanced memory retention in the novel object task. All mice performed equally on the marble bury task. Each cohort started with unique microbiota which showed marked changes in the beta diversity of their microbiota after exposure. In both cohorts, at 7- weeks post exposure, infected mice had more Alistipes sp. and Bacteroides thetaiotaomicron and less Turicibacter sp. and Ligilactobacillus sp. than uninfected mice. At 10 weeks, infected mice had more Alistipes sp. and fewer Muribaculaceae sp. Interestingly, taxon shifts in infected mice were those typically associated with protective effects on liver disease and IL-10 gut conditions, suggesting a possible protective role of the shifted microbiome. Our analyses did not indicate associations between behavioral measures and microbiome composition; however, this could be due to the strong impact of infection on the microbiome composition. Findings here uncover behavioral and cognitive impacts of schistosome infection and shed light on the complex interplay between schistosome infection, behavioral changes, and host microbiome composition, which could ultimately support future global health efforts.

Community surveys of the prevalence, distribution, and coinfection of helminth and protozoan infections in semiurban and rural areas of Gabon, Central Africa

2025-06-12

Jean Claude Dejon‐Agobé , Christian Chassem-Lapue , Paul Alvyn Nguema-Moure +7 more | PLoS neglected tropical diseases

Background Protozoa and helminths cause significant morbidity and mortality, particularly in tropical and subtropical regions where an accurate understanding of their epidemiological profile is needed to improve their control. In … Background Protozoa and helminths cause significant morbidity and mortality, particularly in tropical and subtropical regions where an accurate understanding of their epidemiological profile is needed to improve their control. In Gabon, a country endemic for a diverse range of both helminths and protozoa, epidemiological data for protozoa are lacking, whereas updated data for helminths are needed. This study aimed to describe the distribution of helminth and protozoan infections in the Moyen-Ogooué province of Gabon. Methods This cross-sectional study included individuals aged one year and older living in the study areas for at least one year. The participants were selected via a stratified sampling procedure. Blood, urine, and stool samples, along with sociodemographic data, were collected. Soil-transmitted helminths (STHs) were diagnosed using the Kato-Katz, coproculture and Harada-Mori techniques. Urogenital schistosomiasis was diagnosed using the urine filtration technique. Intestinal protozoa were diagnosed using the mercurothiolate-iodine-formol technique. Plasmodium spp. and filarial infections were diagnosed by thick blood smear microscopy, and, in addition for filaria, by leucoconcentration technique. Results A total of 1,084 participants were included, with a mean age of 31.6 years (SD: 23.6) and a female-to-male sex ratio of 1.15. The overall prevalence of helminth infections was 36% (95%IC: 33–39), with STHs being most common (21%; 95%CI: 18–23), followed by schistosomiasis (11%; 95%CI: 8 – 13) and filariasis (9%; 95%CI: 7–10). The most prevalent STH species were Trichuris trichiura (11%; 95%CI: 10–14), followed by hookworm (9%; 95%CI: 8–11). The prevalence of Plasmodium spp. was 13% (95%CI: 11–15), and the overall prevalence of intestinal protozoa was 28% (95%CI: 25–31), with Blastocystis hominis (11%; 95%CI: 9–13) and Entamoeba coli (8%; 95%CI: 7–10) being the most common intestinal protozoan species. Coinfections with multiple parasite species were observed in 42% of the infected participants, predominantly involving T. trichiura , Schistosoma haematobium , and Plasmodium spp. infection prevalence varied with age, gender, location, and occupation. Conclusion This study reveals a moderate prevalence of helminths and protozoa in our community, with age, gender, and location playing a significant role in their distribution, as do common coinfections between helminths and protozoa. These findings call for further research to provide valuable insights for controlling helminth transmission in the region.

Schistosomiasis and water resources development in Africa: A scoping review and multi-case evaluation of associated snail control

2025-06-12

May N. Sule , Ibrahim El Lahham , Mutinta N Munkombwe +6 more | PLoS neglected tropical diseases

Background Water resources development (WRD), specifically infrastructural man-made water bodies such as dams and irrigation schemes, are built to improve water supply, provide energy, and enhance food security. However, dams … Background Water resources development (WRD), specifically infrastructural man-made water bodies such as dams and irrigation schemes, are built to improve water supply, provide energy, and enhance food security. However, dams and irrigation schemes may lead to a dramatic increase in the prevalence of schistosomiasis. Methodology/Principal findings We conducted a scoping review of WRD impacts on schistosomiasis transmission risk in Africa using electronic databases including Scopus, Web of Science, and grey literature. From 1483 retrieved records, we assessed 186 full-text papers and identified 122 articles covering 54 dams and irrigation schemes in 32 African countries. We found that, although the relationship between WRD and schistosomiasis transmission risk is well-documented in the scientific literature, the vast majority of the approximately 1,600 medium- to large-sized dams currently operating in endemic regions of Africa lack before-and-after prevalence data necessary to evaluate their actual impact on schistosomiasis transmission. Our analysis revealed that rigorous epidemiological data to assess WRD’s effects exist for only 11 dams across 9 countries. Additionally, only a limited number of studies provided information on schistosomiasis control methods, surveillance, or monitoring for WRD. Few countries have implemented engineering and biological snail control measures, some of which have proven effective, enabling us to identify successful interventions employed at various stages of the WRD lifecycle. Lastly, to assess these measures in detail, we selected case studies from Africa that illustrate the success and challenges of schistosomiasis control with regard to WRD, thus gaining insights of the global relevance of lessons learnt for the future development of water resources. Conclusions/Significance Our analysis highlighted that an integrated and coordinated approach is vital for the successful control of schistosomiasis transmission risk associated with Water Resources Development. We provide key recommendations which could be adopted by the Continental Africa Water Investment Programme (AIP) with the ultimate goal of decreasing prevalence and moving towards elimination.

Prévalence de la schistosomose urinaire, des parasites intestinaux et du paludisme chez les enfants en âge préscolaire et scolaire des familles déplacées au Mali

2025-06-11

Oumar Coulibaly , Hamma Maiga , Mahamadou Magassa +7 more | International Journal of Biological and Chemical Sciences

La schistosomiase est un problème de santé publique au Mali. En raison de la récente flambée de violence intercommunautaire au Mali, de nombreuses personnes se sont réfugiées dans les camps … La schistosomiase est un problème de santé publique au Mali. En raison de la récente flambée de violence intercommunautaire au Mali, de nombreuses personnes se sont réfugiées dans les camps à la périphérie de Bamako. L’objectif de cette étude était d’évaluer la prévalence de la schistosomiase urinaire et des parasites intestinaux chez les enfants d'âge préscolaire et scolaire (EApS) des familles déplacées dans le district de Bamako. Nous avons mené une étude transversale chez les EApS de novembre à décembre 2023. L'enquête a couvert les camps des déplacés de Senou, Baguinéda et Niamana et les autochtones de Niamana. Les urines et les selles ont été examinées par la technique de filtration et le Kato-Katz, respectivement. Une goutte épaisse a été réalisée chez chaque enfant pour évaluer la prévalence du paludisme. Au total, 412 EApS ont été inclus avec 222 issus des déplacées et 190 des autochtones. La prévalence de Schistosoma haematobium était de 8,6% chez les déplacés comparée à 2,6% chez les autochtones, p<0,01. La prévalence des parasites intestinaux chez les enfants déplacés était de 1,8% versus les autochtones (4,7%), p=0,89. La prévalence du paludisme était plus élevée chez les déplacés (11,7%) que chez les autochtones (1,6%), p<0,001. Le taux d’hémoglobine était plus élevé mais pas significatif chez les déplacés (14%) que chez les autochtones (8%), p=0,051. En conclusion, la prévalence de la schistosomiase urinaire et du paludisme chez les EApS était plus élevée chez les enfants déplacés que chez les enfants autochtones au Mali. Schistosomiasis is a public health problem in Mali. Due to the recent outbreak of intercommunal violence in Mali, many people have taken refuge in camps on the outskirts of Bamako. The objective of this study was to assess the prevalence of urinary schistosomiasis and intestinal parasites among preschool and school-aged children (EApS) from displaced families in the Bamako district. We conducted a cross-sectional study among EApS from November to December 2023. The survey covered the camps of Senou, Baguinéda and Niamana and indigenous of Niamana. Urine and stool were examined by the filtration technique and Kato-Katz, respectively. A thick blood drop and hemoglobin were taken from each child to assess the prevalence of malaria. A total, 412 EApS were included with 222 from displaced and 190 from natives. The prevalence of Schistosoma haematobium was 8.6% in displaced compared to 2.6% in natives, p<0.01. The prevalence of intestinal parasites in displaced children was 1.8% versus natives (4.7%), p=0.89. Malaria prevalence was higher in displaced (11.7%) than natives (1.6%), p<0.001. The hemoglobin level was higher but not significant in the displaced (14%) than the natives (8%), p=0.051. In conclusion, the prevalence of urinary schistosomiasis and malaria in EApS was higher in displaced than natives’ children in Mali.

Investigating E. coli Strain HT115-mediated RNA Interference in the Treatment of Gastrointestinal Nematode Infection by Ascaris lumbricoides

2025-06-11

Tabassum Howlader , Airong Xiang , Adam Al-Khalili | University of Ottawa Science Undergraduate Research Journal

Nematodes are parasitic worms in the body that can lead to a variety of health problems. One subset of these nematodes are called Ascaris lumbricoides, which proliferate within the intestine. … Nematodes are parasitic worms in the body that can lead to a variety of health problems. One subset of these nematodes are called Ascaris lumbricoides, which proliferate within the intestine. This is the most common worm affecting humans, infecting over hundreds of millions globally. A common method of nematode infection is through contact with soil contaminated with their eggs. This experiment attempts to disrupt the VENOM gene of A. lumbricoides to prevent their function in human hosts and lead to expulsion of the worm. This experiment begins with editing a gut bacterium to deliver RNA interference molecules to target the VENOM gene and lead to parasite expulsion. We propose two delivery methods of secretion: the first is to use the outer membrane vesicles to package and deliver the RNA and the second is to directly secrete the RNAi using a bacterial Type 3 secretion system. We propose that in both methods after the release of the RNAi, it will be absorbed by the worm and downregulate the VENOM gene leading to the worm's death. These findings will be able to provide valuable insight into improving current therapies and potentially give insight on how we can prevent recurrence of nematode infection.

Malnutrition and intestinal parasitic infections: a cross‑sectional survey of hospitalized malnourished children in the Kumasi Metropolis, Ghana

2025-06-10

S. Mensah , John Asiedu Larbi | Journal of Parasitic Diseases

Prevalence and risk factors of intestinal parasitic infections among preschool and school-aged children in Egypt: a systematic review and meta-analysis

2025-06-10

Ahmed Azzam , Heba Khaled | BMC Public Health