Infections by the soil-transmitted helminths (STH), including Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale/Necator americanus (hookworms), and Strongyloides stercoralis, disproportionately affect children around the world. Because of their transmission associated with poor sanita...ry conditions and inadequate hygiene practices, higher burden of disease is seen in children from developing countries from sub-Saharan Africa, Southeast Asia, and Latin America. Approximately 267 million preschool-age children (PSAC) and 568 million school-age children (SAC) worldwide are at risk of STH infection as well as impaired child growth and cognitive development from A. lumbricoides, T. trichiura, and hookworm infections, and death due to severe S. stercoralis infection. Thus, their control is a global health priority.
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Background: The human helminth infections include ascariasis, trichuriasis, hookworm infections, schistosomiasis, lymphatic filariasis (LF) and onchocerciasis. It is estimated that almost 2 billion people worldwide are infected with helminths. Whilst the WHO treatment guidelines for helminth infecti...ons are mostly aimed at controlling morbidity, there has been a recent shift with some countries moving towards goals of disease elimination through mass drug administration, especially for LF and onchocerciasis. However, as prevalence is driven lower, treating entire populations may no longer be the most efficient or cost-effective strategy. Instead, it may be beneficial to identify individuals or demographic groups who are persistently infected, often termed as being “predisposed” to infection, and target treatment at them.
Methods: The authors searched Embase, MEDLINE, Global Health, and Web of Science for all English language, humanbased papers investigating predisposition to helminth infections published up to October 31st, 2017. The varying definitions used to describe predisposition, and the statistical tests used to determine its presence, are summarised. Evidence for predisposition is presented, stratified by helminth species, and risk factors for predisposition to infection are identified and discussed.
Results: In total, 43 papers were identified, summarising results from 34 different studies in 23 countries. Consistent evidence of predisposition to infection with certain species of human helminth was identified. Children were regularly found to experience greater predisposition to Ascaris lumbricoides, Schistosoma mansoni and S. haematobium than adults. Females were found to be more predisposed to A. lumbricoides infection than were males. Household clustering of infection was identified for A. lumbricoides, T. trichiura and S. japonicum. Ascaris lumbricoides and T. trichiura also showed evidence of familial predisposition. Whilst strong evidence for predisposition to hookworm infection was identified, findings with regards to which groups were affected were considerably more varied than for other helminth species.
Conclusion: This review has found consistent evidence of predisposition to heavy (and light) infection for certain human helminth species. However, further research is needed to identify reasons for the reported differences between demographic groups. Molecular epidemiological methods associated with whole genome sequencing to determine ‘who infects whom’ may shed more light on the factors generating predisposition.
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Website last accessed on 04.04.2023
A step-by-step guide for teachers on how to conduct a school deworming day!
Background: Despite several cycles of Mass Drug Administration (MDA), however, the prevalence of Soil-transmitted helminthiasis (STH) remains high in Bangladesh. A clear understanding of local knowledge, attitudes, and practices (KAP) related to the acceptance and utilization of MDA is critical for ...effective implementation of this intervention.
Methods: This research, a cross-sectional descriptive study that utilized quantitative methods, was conducted between February and June 2017. A total of 380 questionnaire surveys were distributed to school-aged children (SAC), the parents of SAC, and school teachers.
Results: Out of 160 SACs, 81.9% knew of STH and 75.6% knew of MDA. SAC showed a high awareness of STH and recognized the importance of preventive measures and MDA. In terms of the parents of SAC and school teachers, close to half of the respondents were knowledgeable about STH and MDA. While nearly all of the participants held positive attitudes toward MDA, the respondents pointed out that school-based MDA presents severe limitations, as non-school-going children are neglected by this effort. A total of 68.3% of all school teachers and 56.8% of all parents of SAC found MDA efforts to be effective.
Conclusion: STH infections still remain a significant public health burden in Bangladesh. Reforming the MDA policy is necessary to achieve the target of STH elimination.
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Soil transmitted helminth (STH) infections are among the most common human infections worldwide with over 1 billion people affected. Many estimates of STH infection are often based on school-aged children (SAC). This study produced predictive risk-maps of STH on a more finite scale, estimated the nu...mber of people infected, and the amount of drug required for preventive chemotherapy (PC) in Ogun state, Nigeria. Georeferenced STH infection data obtained from a cross-sectional survey at 33 locations between July 2016 and November 2018, together with remotely-sensed environmental and socio-economic data were analyzed using Bayesian geostatistical modelling. Stepwise variable selection procedure was employed to select a parsimonious set of predictors to predict risk and spatial distribution of STH infections. The number of persons (pre-school ages children, SAC and adults) infected with STH were estimated, with the amount of tablets needed for preventive chemotherapy. An overall prevalence of 17.2% (95% CI 14.9, 19.5) was recorded for any STH infection. Ascaris lumbricoides infections was the most predominant, with an overall prevalence of 13.6% (95% CI 11.5, 15.7), while Hookworm and Trichuris trichiura had overall prevalence of 4.6% (95% CI 3.3, 5.9) and 1.7% (95% CI 0.9, 2.4), respectively. The model-based prevalence predictions ranged from 5.0 to 23.8% for Ascaris lumbricoides, from 2.0 to 14.5% for hookworms, and from 0.1 to 5.7% for Trichuris trichiura across the implementation units. The predictive maps revealed a spatial pattern of high risk in the central, western and on the border of Republic of Benin. The model identified soil pH, soil moisture and elevation as the main predictors of infection for A. lumbricoides, Hookworms and T. trichiura respectively. About 50% (10/20) of the implementation units require biannual rounds of mass drug administration. Approximately, a total of 1.1 million persons were infected and require 7.8 million doses. However, a sub-total of 375,374 SAC were estimated to be infected, requiring 2.7 million doses. Our predictive risk maps and estimated PC needs provide useful information for the elimination of STH, either for resource acquisition or identifying priority areas for delivery of interventions in Ogun State, Nigeria.
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Website last accessed on 14.04.2023
One of the ongoing challenges with neglected tropical diseases (NTDs) is that the discovery of medicines to treat them has been very slow. Current global programmes for NTDs largely depend on donated medicines, primarily to treat the world’s poorest people ... most of whom live in remote rural or in deprived urban settings.
WHO recently spoke to Mr Robert J. Gyurik, who discovered albendazole in 1972. He took us through the journey that led him to develop the compound.
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oil-transmitted helminth (STH) infections are among the most common infections worldwide and affect the poorest and most deprived communities.
They are transmitted by eggs present in human faeces which in turn contaminate soil in areas where sanitation is poor.
The main species that infect peopl...e are the roundworm (Ascaris lumbricoides), the whipworm (Trichuris trichiura) and the hookworms (Necator americanus and Ancylostoma duodenale).
Intestinal worms produce a wide range of symptoms including intestinal manifestations (diarrhoea, abdominal pain), general malaise and weakness. Hookworms cause chronic intestinal blood loss that result in anaemia.
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Despite pandemic-related disruptions, a total of 76.9 million people received treatment for schistosomiasis in 2020, representing a global coverage of 31.9%, compared with 105 million treated in 2019 (coverage of 44.8%).
The latest data published by the World Health Organization (WHO) show that 2...8.6 million fewer people were treated for schistosomiasis (bilharzia) in 2020 than in 2019. This 27% drop in the number of treatments delivered is largely due to the implementation of COVID-19 measures, including school closures.
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Soil-transmitted helminth (STH) infections are among the most common infections worldwide with an estimated 1.5 billion infected people or 24% of the world’s population. These infections affect the poorest and most deprived communities with poor access to clean water, sanitation and hygiene in tro...pical and subtropical areas, with the highest prevalence reported from sub-Saharan Africa, China, South America and Asia. They are transmitted by eggs present in human faeces, which in turn contaminate soil in areas where sanitation is poor. Over 260 million preschool-age children, 654 million school-age children,108 million adolescent girls and 138.8 million pregnant and lactating women live in areas where these parasites are intensively transmitted, and are in need of treatment and preventive interventions.
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Las geohelmintiasis son una de las parasitosis más comunes en el mundo, y se estima que 1500 millones de personas, el 24 % de la población mundial, están infestadas. Estas infestaciones afectan a las comunidades más pobres y desfavorecidas de zonas tropicales y subtropicales con un acceso defici...ente a servicios de agua limpia, saneamiento e higiene, y la prevalencia más alta se ha notificado en el África subsahariana, China, América del Sur y Asia. Las geohelmintiasis transmiten a través de los huevos de los parásitos eliminados con las heces fecales de las personas infestadas, que, a su vez, contaminan el suelo en zonas donde el saneamiento es deficiente. Más de 260 millones de niños en edad preescolar, 654 millones de niños en edad escolar, 108 millones de niñas adolescentes y 138,8 millones de embarazadas y madres lactantes viven en zonas donde la transmisión de esos parásitos es intensa y, por esa razón, necesitan tratamientos e intervenciones preventivas.
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Les géohelminthiases comptent parmi les infections les plus courantes dans le monde, plus de 1,5 milliard de personnes, soit près de 24 % de la population mondiale, étant infestées à l’échelle mondiale. Ces infections touchent les communautés les plus pauvres et les plus défavorisées ayan...t un accès limité à l’eau potable, à l’assainissement et à l’hygiène dans les régions tropicales et subtropicales, la plus forte prévalence étant recensée en Afrique subsaharienne, en Chine, en Amérique du Sud et en Asie. Elles se transmettent par des œufs présents dans les excréments humains, qui contaminent les sols là où les conditions d’assainissement sont insuffisantes. Plus de 260 millions d’enfants d’âge préscolaire, 654 millions d’enfants d’âge scolaire, 108 millions d’adolescentes et 138,8 millions de femmes enceintes ou allaitantes vivent dans des zones où il existe une transmission à grande échelle de ces parasites et nécessitent un traitement et la mise en place de mesures préventives.
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Передающиеся через почву гельминтозы (ППГ) относятся к наиболее распространенным инвазиям во всем мире и, согласно расчетам, поражают 1,5 млрд человек, или 24% мирово...о населения. Они поражают беднейшие и наиболее обездоленные группы населения, не имеющие полноценного доступа к чистому водоснабжению и санитарно-гигиеническим средствам, на территории тропических и субтропических районов и, по имеющимся данным, наиболее распространены в странах Африки к югу от Сахары, Китае, Южной Америке и Азии. Они передаются через яйца, присутствующие в фекалиях человека, которые в неблагополучных с санитарной точки зрения районах попадают в почву. В районах интенсивной передачи данных паразитов проживает более 260 млн детей дошкольного возраста, 654 млн детей школьного возраста, 108 млн девочек-подростков и 138,8 млн беременных и кормящих грудью женщин, все из которых нуждаются в лечении и профилактике.
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عد عدوى الديدان الطفيلية المنقولة بالتربة من بين أكثر أنواع العدوى شيوعاً في العالم، مع وجود ما يقدّر بـ1,5 مليار شخص مصاب بها في جميع أنحاء العالم، أو ما يعادل 24٪ من ...كان العالم. وتؤثر هذه الإصابات على أفقر المجتمعات وأكثرها حرماناً، حيث تعاني هذه المجتمعات من ضعف فرص الحصول على المياه النظيفة والصرف الصحي والنظافة الصحية في المناطق المدارية وشبه المدارية، مع الإبلاغ عن أعلى معدل انتشار لها في أفريقيا جنوب الصحراء الكبرى والصين وأمريكا الجنوبية وآسيا. وتنتقل العدوى عن طريق البيوض الموجودة في البراز البشري الذي يلوث التربة في المناطق التي تعاني من رداءة مرافق الصرف الصحي. ويعيش أكثر من 260 مليون طفل في سن ما قبل المدرسة، و654 مليون طفل في سن المدرسة، و108 ملايين مراهق، و138,8 مليون حامل ومرضع في مناطق تنتقل فيها هذه الطفيليات بشكل مكثف، ويحتاجون إلى العلاج والتدخلات الوقائية.
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Soil-transmitted helminth (STH) infections are among the most common infections worldwide and affect the poorest and most deprived communities. They are transmitted by eggs present in human faeces which in turn contaminate soil in areas where sanitation is poor.
As a high-burden neglected tropical disease, soil-transmitted helminth (STH) infections remain a major problem in the world, especially among children under five years of age. Since young children are at high risk of being infected, STH infection can have a long-term negative impact on their life, i...ncluding impaired growth and development. Stunting, a form of malnutrition in young children, has been long assumed as one of the risk factors in acquiring the STH infections. However, the studies on STH infection in children under five with stunting have been lacking, resulting in poor identification of the risk. Accordingly, we collected and reviewed existing related research articles to provide an overview of STH infection in a susceptible population of stunted children under five years of age in terms of prevalence and risk factors. There were 17 studies included in this review related to infection with Ascaris lumbricoides, Trichuris trichiura, hookworm, and Strongyloides stercoralis from various countries. The prevalence of STH infection in stunted children ranged from 12.5% to 56.5%. Increased inflammatory markers and intestinal microbiota dysbiosis might have increased the intensity of STH infection in stunted children that caused impairment in the immune system. While the age from 2 to 5 years along with poor hygiene and sanitation has shown to be the most common risk factors of STH infections in stunted children; currently there are no studies that show direct results of stunting as a risk factor for STH infection. While stunting itself may affect the pathogenesis of STH infection, further research on stunting as a risk factor for STH infection is encouraged.
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Worm infestation is a common issue that is seen mostly among children. However, this issue can be found among adults as well due to the change in lifestyle patterns. In most cases, worm infestation is not a life-threatening infection but it can lead to various clinical problems.
Accessed on 22.04.2023
To target helminth elimination, a new consortium of research institutes, universities, not-for-profit organizations, and pharmaceutical companies have joined forces and expertise to establish a research and development pipeline for the development of anthelminthics targeti...ng nematodes. The focus is on STH as well as onchocerciasis.
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Website last accessed on 01.07.2023
The National Deworming Day is an initiative of Ministry of Health and Family Welfare, Government of India to make every child in the country worm free. This is one of the largest public health programs reaching large number of children during a short period.
Website last accessed on 01.07.2023