ResearchPad - soil-transmitted-helminthiases https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Integrating testing for chronic strongyloidiasis within the Indigenous adult preventive health assessment system in endemic communities in the Northern Territory, Australia: An intervention study]]> https://www.researchpad.co/article/elastic_article_13848 Strongyloidiasis is a neglected tropical disease that is endemic in some Aboriginal communities in the Northern Territory. This study asks if the number and proportion of persons tested for chronic strongyloidiasis can be increased by incorporating a Strongyloides serology test into the existing routine Indigenous adult preventive health assessment system in remote endemic communities. This study demonstrated that integrating Strongyloides serology test within the Indigenous adult preventive health assessment system does increase the number and proportion of people tested in endemic communities. This intervention means that life-threatening clinical complications of strongyloidiasis can be prevented by early detection and treatment. Primary health care services have an important role in increased testing in this high-risk population. Primary health care clinicians incorporated chronic strongyloidiasis with other preventable chronic and infectious diseases. The sustainable population health systems-based approach successfully increased coverage by integrating testing for chronic strongyloidiasis into the adult preventive health assessment in health services in remote Indigenous Australian endemic communities, utilising the electronic health record system. The Strongyloides report developed to measure the change in clinical practice would be replicable in other health services with high risk populations.

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<![CDATA[Gender norms and mass deworming program access in Comé, Benin: A qualitative assessment of gender-associated opportunities and challenges to achieving high mass drug administration coverage]]> https://www.researchpad.co/article/N0cbc3c85-9c5e-43fe-983c-4afc7d1b8db3

The World Health Organization’s Neglected Tropical Disease Roadmap has accelerated progress towards eliminating select neglected tropical diseases (NTDs). This momentum has catalyzed research to determine the feasibility of interrupting transmission of soil-transmitted helminths (STH) using community-wide mass drug administration (MDA). This study aims to identify potential gender-specific facilitators and barriers to accessing and participating in community-wide STH MDA, with the goal of ensuring programs are equitable and maximize the probability of interrupting STH transmission. This research was conducted prior to the launch of community-wide MDA for STH in Comé, Benin. A total of 10 focus group discussions (FGDs) were conducted separately among 40 men, 38 women, and 15 community drug distributors (CDDs). Salient themes included: both men and women believe that community-wide MDA would reduce the financial burden associated with self-treatment, particularly for low income adults. Community members believe MDA should be packaged alongside water, sanitation, and other health services. Women feel past community-wide programs have been disorganized and are concerned these distributions will be similar. Women also expressed interest in increased engagement in the implementation of future community-based public health programs. Men often did not perceive themselves to be at great risk for STH infection and did not express a high demand for treatment. Finally, the barriers discussed by CDDs generally did not align with gender-specific concerns, but rather represented concerns shared by both genders. A door-to-door distribution strategy for STH MDA is preferred by women in this study, as this platform empowers women to participate as health decision makers for their family. In addition, involving women in planning and implementation of community-wide programs may help to increase treatment coverage and compliance.

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<![CDATA[Integrated delivery of school health interventions through the school platform: Investing for the future]]> https://www.researchpad.co/article/5c5ca2c3d5eed0c48441ea70

School health and nutrition (SHN) programmes are recognized as a significant contributor to both health and education sector goals. The school system offers an ideal platform from which to deliver basic health interventions that target the most common health conditions affecting school-age children (SAC) in low-income countries, leading to improved participation and learning outcomes. However, governments require evidence to cost, design, and implement these programmes. In Ethiopia, prevalent health conditions affecting SAC's education participation and learning outcomes include infection with soil-transmitted helminths (STHs), hunger, and malnutrition. In recognition of the multiple issues affecting the health and education of SAC, the government has taken a proactive approach, coordinating an integrated SHN programme designed to be implemented in partnership and monitored and financed through a single, integrated mechanism. The programme, known as the Enhanced School Health Initiative (ESHI), integrates three complimentary health interventions: deworming; school feeding; and provision of a water, sanitation, and hygiene (WASH) package in schools, which in delivery aim to maximize the benefits of each of the individual components. Operational research surrounding the ESHI programme includes both qualitative and quantitative analyses. Here, we present an overview of the ESHI programme and its genesis. We also introduce three additional supporting papers that provide in-depth analyses of key findings, including the baseline situational analysis, the costs, and community perceptions of the programme. The findings from ESHI provide initial evidence to develop an understanding of the related costs and synergies of integrating multiple health interventions onto a single platform. The work has translated into strengthened institutional capacity and improved cross-sectoral coordination. The government is now committed to supporting 25 million school children in Ethiopia through SHN. The ESHI model serves as a reference point for other countries looking to scale up targeted SHN interventions.

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<![CDATA[Epidemiology of Strongyloides stercoralis infection in Bolivian patients at high risk of complications]]> https://www.researchpad.co/article/5c4a305ad5eed0c4844bfdec

Background

Strongyloidiasis can be fatal in immunocompromised patients, but few epidemiological studies investigated the burden of this neglected tropical disease among these populations, particularly in low- and middle-income countries such as Bolivia. This study aimed to fill in this gap by estimating prevalence rate and risk factors associated with strongyloidiasis among patients at high risk of complications

Methods

A cross-sectional study was carried out in Santa Cruz (elevation 400 meters, tropical climate) and Cochabamba (elevation 2,500 meters, temperate climate), among patients with cancer, HIV infection and rheumatic or hematologic disease, using four coproparasitological techniques and one serological (ELISA) test.

Results

In total, 1,151 patients participated in this study, including individuals who were HIV-positive (30%) or with rheumatic (29%), oncologic (32%) or hematologic (9%) diseases. The serological and coproparasitological prevalence was 23.0% (95% confidence interval [CI], 20.7–25.5; n = 265/1151) and 7.6% (95% CI, 6.2–9.3; n = 88/1151), respectively, with an estimated actual prevalence of 20.2% (95% CI, 17.9–22.5). Positive serology and positive coproparasitology were associated with younger age and lower education levels. There was no significant difference in prevalence between Cochabamba and Santa Cruz as defined by coproparasitology (6.4% vs. 8.9%; p = 0.11) or serology (24.0% vs. 22.0%; p = 0.4). Among 64 patients in Cochabamba who had never travelled to the tropical lowlands, 5 (7.8%) had a positive coproparasitology.

Conclusions

Strongyloidiasis is widely prevalent in Bolivia among vulnerable patients at increased risk of life-threatening complications. Transmission of the parasite occurs both in tropical lowlands and temperate elevation (≥ 2,500 m). Control strategies to prevent transmission and complications of this serious parasitic disease should be urgently reinforced.

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<![CDATA[China’s shifting neglected parasitic infections in an era of economic reform, urbanization, disease control, and the Belt and Road Initiative]]> https://www.researchpad.co/article/5c536c43d5eed0c484a49c8e ]]> <![CDATA[Exclusive dependence of IL-10Rα signalling on intestinal microbiota homeostasis and control of whipworm infection]]> https://www.researchpad.co/article/5c46652cd5eed0c484517cee

The whipworm Trichuris trichiura is a soil-transmitted helminth that dwells in the epithelium of the caecum and proximal colon of their hosts causing the human disease, trichuriasis. Trichuriasis is characterized by colitis attributed to the inflammatory response elicited by the parasite while tunnelling through intestinal epithelial cells (IECs). The IL-10 family of receptors, comprising combinations of subunits IL-10Rα, IL-10Rβ, IL-22Rα and IL-28Rα, modulates intestinal inflammatory responses. Here we carefully dissected the role of these subunits in the resistance of mice to infection with T. muris, a mouse model of the human whipworm T. trichiura. Our findings demonstrate that whilst IL-22Rα and IL-28Rα are dispensable in the host response to whipworms, IL-10 signalling through IL-10Rα and IL-10Rβ is essential to control caecal pathology, worm expulsion and survival during T. muris infections. We show that deficiency of IL-10, IL-10Rα and IL-10Rβ results in dysbiosis of the caecal microbiota characterised by expanded populations of opportunistic bacteria of the families Enterococcaceae and Enterobacteriaceae. Moreover, breakdown of the epithelial barrier after whipworm infection in IL-10, IL-10Rα and IL-10Rβ-deficient mice, allows the translocation of these opportunistic pathogens or their excretory products to the liver causing organ failure and lethal disease. Importantly, bone marrow chimera experiments indicate that signalling through IL-10Rα and IL-10Rβ in haematopoietic cells, but not IECs, is crucial to control worm expulsion and immunopathology. These findings are supported by worm expulsion upon infection of conditional mutant mice for the IL-10Rα on IECs. Our findings emphasize the pivotal and complex role of systemic IL-10Rα signalling on immune cells in promoting microbiota homeostasis and maintaining the intestinal epithelial barrier, thus preventing immunopathology during whipworm infections.

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<![CDATA[High seroprevalence of Strongyloides stercoralis among individuals from endemic areas considered for solid organ transplant donation: A retrospective serum-bank based study]]> https://www.researchpad.co/article/5c09940cd5eed0c4842ae1af

Background

Strongyloides stercoralis is a worldwide disseminated parasitic disease that can be transmitted from solid organ transplant (SOT) donors to recipients. We determined the serological prevalence of S. stercoralis among deceased individuals from endemic areas considered for SOT donation, using our institution’s serum bank.

Methodology

Retrospective study including all deceased potential donors from endemic areas of strongyloidiasis considered for SOT between January 2004 and December 2014 in a tertiary care hospital. The commercial serological test IVD-Elisa was used to determine the serological prevalence of S. stercoralis.

Principal findings

Among 1025 deceased individuals during the study period, 90 were from endemic areas of strongyloidiasis. There were available serum samples for 65 patients and 6 of them tested positive for S. stercoralis (9.23%). Only one of the deceased candidates was finally a donor, without transmitting the infection.

Conclusions

Among deceased individuals from endemic areas considered for SOT donation, seroprevalence of strongyloidiasis was high. This highlights the importance of adhering to current recommendations on screening for S. stercoralis among potential SOT donors at high risk of the infection, together with the need of developing a rapid diagnostic test to fully implement these screening strategies.

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<![CDATA[Predicted short and long-term impact of deworming and water, hygiene, and sanitation on transmission of soil-transmitted helminths]]> https://www.researchpad.co/article/5c12cfa7d5eed0c484914b46

Background

Regular preventive chemotherapy (PCT) targeting high-risk populations is an effective way to control STH in the short term, but sustainable long-term STH control is expected to require improved access to water, sanitation, and hygiene (WASH). However, experimental studies have not been able to conclusively demonstrate the benefit of WASH in preventing STH (re-)infections. We investigated the impact of WASH on STH infections during and after PCT using mathematical modelling.

Methods and findings

We use the individual-based transmission model WORMSIM to predict the short and long-term impact of WASH on STH transmission in contexts with and without PCT. We distinguish two WASH modalities: sanitation, which reduces individuals’ contributions to environmental contamination; and hygiene, which reduces individuals’ exposure to infection. We simulate the impact of varying levels of uptake and effectiveness of each WASH modality, as well as their combined impact. Clearly, sanitation and hygiene interventions have little observable short-term impact on STH infections levels in the context of PCT. However, in the long term, both are pivotal to sustain control or eliminate infection levels after scaling down or stopping PCT. The impact of hygiene is determined more by the effectiveness of the intervention than its overall uptake, whereas the impact of sanitation depends more directly on the product of uptake and the effectiveness.

Interpretation

The impact of WASH interventions on STH transmission highly depends on the worm species, WASH modality, and uptake and effectiveness of the intervention. Also, the impact of WASH is difficult to measure in the context of ongoing PCT programmes. Still, we show a clear added benefit of WASH to sustain the gains made by PCT in the long term, such that PCT may be scaled down or even stopped altogether. To safely stop or scale down PCT, policy for WASH and PCT should be integrated.

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<![CDATA[2,4-Diaminothieno[3,2-d]pyrimidines, a new class of anthelmintic with activity against adult and egg stages of whipworm]]> https://www.researchpad.co/article/5b5fed7c463d7e1703b809c3

The human whipworm Trichuris trichiura is a parasite that infects around 500 million people globally, with consequences including damage to physical growth and educational performance. Current drugs such as mebendazole have a notable lack of efficacy against whipworm, compared to other soil-transmitted helminths. Mass drug administration programs are therefore unlikely to achieve eradication and new treatments for trichuriasis are desperately needed. All current drug control strategies focus on post-infection eradication, targeting the parasite in vivo. Here we propose developing novel anthelmintics which target the egg stage of the parasite in the soil as an adjunct environmental strategy. As evidence in support of such an approach we describe the actions of a new class of anthelmintic compounds, the 2,4-diaminothieno[3,2-d]pyrimidines (DATPs). This compound class has found broad utility in medicinal chemistry, but has not previously been described as having anthelmintic activity. Importantly, these compounds show efficacy against not only the adult parasite, but also both the embryonated and unembryonated egg stages and thereby may enable a break in the parasite lifecycle.

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<![CDATA[Diagnostic comparison between FECPAKG2 and the Kato-Katz method for analyzing soil-transmitted helminth eggs in stool]]> https://www.researchpad.co/article/5b28b5dc463d7e1340e24746

Background

Over one billion people are infected with soil-transmitted helminths (STH), i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura. For estimating drug efficacy and monitoring anthelminthic drug resistance, accurate diagnostic methods are critical. FECPAKG2 is a new remote-diagnostic tool used in veterinary medicine, which produces an image of the stool sample that can be stored on an internet cloud. We compared for the first time FECPAKG2 with the recommended Kato-Katz method.

Methodology/Principal findings

Two stool samples were collected from adolescent participants (age 15–18 years) at baseline and 14 to 21 days after treatment in the framework of a randomized clinical trial on Pemba Island, Tanzania. Stool samples were analyzed with different diagnostic efforts: i) one or ii) two Kato-Katz thick smears from the first sample, iii) two Kato-Katz thick smears from two samples and iv) FECPAKG2 from the first sample. Parameters were calculated based on a hierarchical Bayesian egg count model.

Complete data for all diagnostic efforts were available from 615 participants at baseline and 231 hookworm-positive participants at follow-up. At baseline FECPAKG2 revealed a sensitivity of 75.6% (72.0–77.7) for detecting A. lumbricoides, 71.5% (67.4–95.3) for hookworm and 65.8% (64.9–66.2) for T. trichiura, which was significantly lower (all p<0.05) than any of the Kato-Katz methods and highly dependent on infection intensity. Despite that the egg counts based on FECPAKG2 were relatively lower compared to Kato-Katz by a ratio of 0.38 (0.32–0.43) for A. lumbricoides, 0.36 (0.33–0.40) for hookworm and 0.08 (0.07–0.09) for T. trichiura, the egg reduction rates (ERR) were correctly estimated with FECPAKG2.

Conclusions/Significance

The sensitivity to identify any STH infection was considerably lower for FECPAKG2 compared to Kato-Katz. Following rigorous development, FECPAKG2 might be an interesting tool with unique features for epidemiological and clinical studies.

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<![CDATA[Helminth Infections, Type-2 Immune Response, and Metabolic Syndrome]]> https://www.researchpad.co/article/5989da83ab0ee8fa60b9b441 ]]> <![CDATA[The Global Burden of Disease Study 2010: Interpretation and Implications for the Neglected Tropical Diseases]]> https://www.researchpad.co/article/5989da7eab0ee8fa60b999d9 ]]> <![CDATA[Effect of Deworming on Physical Fitness of School-Aged Children in Yunnan, China: A Double-Blind, Randomized, Placebo-Controlled Trial]]> https://www.researchpad.co/article/5989d9fdab0ee8fa60b72c0e

Background

There is considerable debate on the health impacts of soil-transmitted helminth infections. We assessed effects of deworming on physical fitness and strength of children in an area in Yunnan, People's Republic of China, where soil-transmitted helminthiasis is highly endemic.

Methodology

The double-blind, randomized, placebo-controlled trial was conducted between October 2011 and May 2012. Children, aged 9–12 years, were treated with either triple-dose albendazole or placebo, and monitored for 6 months post-treatment. The Kato-Katz and Baermann techniques were used for the diagnosis of soil-transmitted helminth infections. Physical fitness was assessed with a 20-m shuttle run test, where the maximum aerobic capacity within 1 min of exhaustive exercise (VO2 max estimate) and the number of 20-m laps completed were recorded. Physical strength was determined with grip strength and standing broad jump tests. Body height and weight, the sum of skinfolds, and hemoglobin levels were recorded as secondary outcomes.

Principal Findings

Children receiving triple-dose albendazole scored slightly higher in the primary and secondary outcomes than placebo recipients, but the difference lacked statistical significance. Trichuris trichiura-infected children had 1.6 ml kg−1 min−1 (P = 0.02) less increase in their VO2 max estimate and completed 4.6 (P = 0.04) fewer 20-m laps than at baseline compared to non-infected peers. Similar trends were detected in the VO2 max estimate and grip strength of children infected with hookworm and Ascaris lumbricoides, respectively. In addition, the increase in the VO2 max estimate from baseline was consistently higher in children with low-intensity T. trichiura and hookworm infections than in their peers with high-intensity infections of all soil-transmitted helminths (range: 1.9–2.1 ml kg−1 min−1; all P<0.05).

Conclusions/Significance

We found no strong evidence for significant improvements in physical fitness and anthropometric indicators due to deworming over a 6-month follow-up period. However, the negative effect of T. trichiura infections on physical fitness warrants further investigation.

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<![CDATA[Soil-Transmitted Helminths and Schistosoma mansoni Infections in Ethiopian Orthodox Church Students around Lake Tana, Northwest Ethiopia]]> https://www.researchpad.co/article/5989d9dfab0ee8fa60b691fc

Background

Soil-transmitted helminths (STH) and Schistosoma mansoni infections are the major neglected tropical diseases that result in serious consequences on health, education and nutrition in children in developing countries. The Ethiopian Orthodox church students, who are called Yekolotemari in Amharic, live in areas with poor sanitation and hygiene. Moreover, they are not included in the national STH control programs. Thus, STH and S. mansoni infections prevalence is unknown.

Methods

A cross-sectional study was conducted on 384 students in June 2014 to determine STH and S. mansoni infections prevalence. Moreover, the knowledge of students about STH and S. mansoni was assessed. Data on knowledge and clinical symptoms were collected using structured questionnaires via face to face interview. Stool specimens were examined by formol-ether concentration method.

Results

The overall prevalence of intestinal helminths infections was 85.9% (95% confidence interval (CI): 82.1–89%). STHs infections prevalence was 65.6% (95% CI: 60.7–70.2%). The prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura were 31.8% (95% CI: 27.3–36.6%), 29.4% (25–31%) and 3.1% (1.8–5.4%), respectively. On the other hand, S. mansoni prevalence was 14.3% (95% CI: 11.1–18.1%). Majority of students infected with S. mansoni had bloody stool with crud odds-ratio of 2.9 (95% CI: 1.5–5.5). Knowledge assessment showed that 50 (13%) and 18 (4.9%) of the respondents knew about transmission of STH and S. mansoni, respectively.

Conclusions

The prevalence of STH and S. mansoni infections were high thus de-worming program should include the students of Ethiopian Orthodox churches. Furthermore, provision and use of sanitary facilities, health education for students to create awareness of parasitic infections and improved personal hygiene should be in place.

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<![CDATA[Complexities and Perplexities: A Critical Appraisal of the Evidence for Soil-Transmitted Helminth Infection-Related Morbidity]]> https://www.researchpad.co/article/5989dae9ab0ee8fa60bbeb0b

Background: Soil-transmitted helminths (STH) have acute and chronic manifestations, and can result in lifetime morbidity. Disease burden is difficult to quantify, yet quantitative evidence is required to justify large-scale deworming programmes. A recent Cochrane systematic review, which influences Global Burden of Disease (GBD) estimates for STH, has again called into question the evidence for deworming benefit on morbidity due to STH. In this narrative review, we investigate in detail what the shortfalls in evidence are. Methodology/Principal Findings: We systematically reviewed recent literature that used direct measures to investigate morbidity from STH and we critically appraised systematic reviews, particularly the most recent Cochrane systematic review investigating deworming impact on morbidity. We included six systematic reviews and meta-analyses, 36 literature reviews, 44 experimental or observational studies, and five case series. We highlight where evidence is insufficient and where research needs to be directed to strengthen morbidity evidence, ideally to prove benefits of deworming. Conclusions/Significance: Overall, the Cochrane systematic review and recent studies indicate major shortfalls in evidence for direct morbidity. However, it is questionable whether the systematic review methodology should be applied to STH due to heterogeneity of the prevalence of different species in each setting. Urgent investment in studies powered to detect direct morbidity effects due to STH is required.

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<![CDATA[A Double-Blind Randomized Controlled Trial of Maternal Postpartum Deworming to Improve Infant Weight Gain in the Peruvian Amazon]]> https://www.researchpad.co/article/5989db54ab0ee8fa60bdcfca

Background

Nutritional interventions targeting the critical growth and development period before two years of age can have the greatest impact on health trajectories over the life course. Compelling evidence has demonstrated that interventions investing in maternal health in the first 1000 days of life are beneficial for both mothers and their children. One such potential intervention is deworming integrated into maternal postpartum care in areas where soil-transmitted helminth (STH) infections are endemic.

Methodology/Principal Findings

From February to August 2014, 1010 mother-infant pairs were recruited into a trial aimed at assessing the effectiveness of maternal postpartum deworming on infant and maternal health outcomes. Following delivery, mothers were randomly assigned to receive either single-dose 400 mg albendazole or placebo. Participants were followed-up at 1 and 6 months postpartum. There was no statistically significant difference in mean weight gain between infants in the experimental and control groups (mean difference: -0.02; 95% CI: -0.1, 0.08) at 6 months of age. Further, deworming had no effect on measured infant morbidity indicators. However, ad hoc analyses restricted to mothers who tested positive for STHs at baseline suggest that infants of mothers in the experimental group had greater mean length gain in cm (mean difference: 0.8; 95% CI: 0.1, 1.4) and length-for-age z-score (mean difference: 0.5; 95% CI: 0.2, 0.8) at 6 months of age.

Conclusions/Significance

In a study population composed of both STH-infected and uninfected mothers, maternal postpartum deworming was insufficient to impact infant growth and morbidity indicators up to 6 months postpartum. Among STH-infected mothers, however, important improvements in infant length gain and length-for-age were observed. The benefits of maternal postpartum deworming should be further investigated in study populations having higher overall prevalences and intensities of STH infections and, in particular, where whipworm and hookworm infections are of public health concern.

Trial registration

ClinicalTrials.gov (NCT01748929).

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<![CDATA[Micronutrient Supplementation and Deworming in Children with Geohelminth Infections]]> https://www.researchpad.co/article/5989da35ab0ee8fa60b85e99 ]]> <![CDATA[Controlling Neglected Tropical Diseases (NTDs) in Haiti: Implementation Strategies and Evidence of Their Success]]> https://www.researchpad.co/article/5989da71ab0ee8fa60b95069

Lymphatic filariasis (LF) and soil-transmitted helminths (STH) have been targeted since 2000 in Haiti, with a strong mass drug administration (MDA) program led by the Ministry of Public Health and Population and its collaborating international partners. By 2012, Haiti’s neglected tropical disease (NTD) program had reached full national scale, and with such consistently good epidemiological coverage that it is now able to stop treatment for LF throughout almost all of the country. Essential to this success have been in the detail of how MDAs were implemented. These key programmatic elements included ensuring strong community awareness through an evidence-based, multi-channel communication and education campaign facilitated by voluntary drug distributors; strengthening community trust of the drug distributors by ensuring that respected community members were recruited and received appropriate training, supervision, identification, and motivation; enforcing a “directly observed treatment” strategy; providing easy access to treatment though numerous distribution posts and a strong drug supply chain; and ensuring quality data collection that was used to guide and inform MDA strategies. The evidence that these strategies were effective lies in both the high treatment coverage obtained– 100% geographical coverage reached in 2012, with almost all districts consistently achieving well above the epidemiological coverage targets of 65% for LF and 75% for STH—and the significant reduction in burden of infection– 45 communes having reached the target threshold for stopping treatment for LF. By taking advantage of sustained international financial and technical support, especially during the past eight years, Haiti’s very successful MDA campaign resulted in steady progress toward LF elimination and development of a strong foundation for ongoing STH control. These efforts, as described, have not only helped establish the global portfolio of “best practices” for NTD control but also are poised to help solve two of the most important future NTD challenges—how to maintain control of STH infections after the community-based LF “treatment platform” ceases and how to ensure appropriate morbidity management for patients currently suffering from lymphatic filarial disease.

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<![CDATA[Compounds Derived from the Bhutanese Daisy, Ajania nubigena, Demonstrate Dual Anthelmintic Activity against Schistosoma mansoni and Trichuris muris]]> https://www.researchpad.co/article/5989daafab0ee8fa60baae66

Background

Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties.

Methodology/Principal Findings

Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds—luteolin (3) and (3R,6R)-linalool oxide acetate (1)—showed dual anthelmintic activity against S. mansoni (IC50 range = 5.8–36.9 μg/mL) and T. muris (IC50 range = 9.7–20.4 μg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC50 = 13.3 μg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice.

Conclusions/Significance

Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths—T. muris and S. mansoni—and was effective against juvenile schistosomes, the stage that is refractory to the current gold standard drug, praziquantel. Medicinal chemistry optimisation including cytotoxicity analysis, analogue development and structure-activity relationship studies are warranted and could lead to the identification of more potent chemical entities for the control of parasitic helminths of humans and animals.

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<![CDATA[Schistosomiasis and Soil Transmitted Helminths Distribution in Benin: A Baseline Prevalence Survey in 30 Districts]]> https://www.researchpad.co/article/5989dae5ab0ee8fa60bbd529

In 2013, Benin developed strategies to control neglected tropical diseases and one of the first step was the disease mapping of the entire country in order to identify endemic districts of schistosomiasis and soil transmitted helminths (STH). This study was carried out in 30 of the 77 districts of Benin. Of these 30 districts 22 were previously treated for Lymphatic Filariasis (LF) using the Ivermectin and Albendazole combination. In each district, five schools were selected and 50 children aged 8 to 14 years were sampled in each school, making a total of 250 children sampled in the district. The schools were selected mainly according to their proximity to lakes or any bodies of water that were likely to have been used by the children. Samples of faeces and urine were collected from each pupil. Urinary schistosomiasis was identified using the urine filtration technique while STH and intestinal schistosomiasis were identified through the Kato Katz method. Overall a total of 7500 pupils were surveyed across 150 schools with a gender ratio of 1:1. Hookworm was identified in all 30 districts with a prevalence ranging from 1.2% (95%CI: 0.0–2.5) to 60% (95%CI: 53.9–66.1). Ascaris lumbricoides was detected in 19 districts with a prevalence rate between 1% (95%CI: 0.0–2.2) and 39% (95%CI: 32.9–45.0). In addition to these common STH, Trichuris trichiura, Enterobius vermicularis and Strongyloides stercoralis were found at low prevalence. Only 16 districts were endemic to Schistosoma mansoni, while 29 districts were endemic to S. haematobium. The S. haematobium prevalence ranged from 0.8% (95% CI: 0.0–1.9) to 56% (95% CI: 50.2–62.5) while the prevalence of S. mansoni varied from 0.4% (95%CI: 0.0–1.2) to 46% (95% CI: 39.8–52.2). The 22 districts, where LF was successfully eliminated, still require mass drug administration (MDA) of albendazole indicating that school-based MDA would be needed even after LF elimination in districts co-endemic to LF and STH in Benin.

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