SCORE <i>S. mansoni</i> Kenya and Tanzania Cohort

Related studies: SCORE S. mansoni Cluster Randomized Trial Background: Schistosomiasis is a parasitic disease caused by infection with blood flukes of the genus Schistosoma. An estimated 800 million people are at risk of infection and more than 200 million people are infected globally. Mass drug administration (MDA) with the drug praziquantel is the mainstay of schistosomiasis control. The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) project conducted multi-year, randomized intervention trials that assessed changes in prevalence and intensity of schistosomiasis in children aged 9-12 years in villages receiving MDA using different strategies over a 4-year intervention period. These longitudinal studies also provided an opportunity to explore the impact of MDA on schistosomiasis-associated morbidity in children. Morbidity associated with Schistosoma mansoni is caused by parasite eggs that are deposited daily into the human host's organs, creating thousands of foci of granulomatous inflammation, particularly in the bowel and liver. These granulomas can cause critical dysfunction of the affected organs, and the granuloma's chronic inflammation contributes to multiple systemic deficits, including chronic pain, diarrhea, anemia and reduced quality of life. Objectives: The objectives of this nested cohort study were to describe changes in anthropometric growth indices, hemoglobin levels, measures of physical fitness, and quality of life, as well as the liver abnormalities and portal vein findings among study cohort children (aged 7-8 years at baseline) at the end of their 4-year study participation. The study hypothesis was that annual community-wide treatment with praziquantel could provide incremental health benefits in terms of reductions in observed morbidity when compared with the effects of a less intensive regimen, that is, every-other-year treatment administered in a school-based program. Methodology Study Sites: The cohort studies were conducted in the SCORE intervention trial regions of Kenya and Tanzania with high prevalence (>25%) of S. mansoni infection. Dates of Data Collection: 2011- 2015 Study Design: Cohort study; morbidity in the selected cohort was evaluated serially at baseline, and after 3 and 5 years. Data Collection: Selection of villages: The large intervention trials in which the cohorts were nested include 25 villages per arm. Four villages each from the most intensive arm and the least intensive arm were randomly selected for inclusion in the cohort study. In Kenya, because fewer than 800 children were enrolled in the eight selected villages, two additional villages were added to each arm, yielding a total of twelve cohort study villages in the Kenya site. Selection of individuals: Children in the selected villages were eligible for the cohort study if they were age 7 or 8 at the start of the study, attended a local school, and did not have a disability that precluded participation in all of the study health measurements, in particular, the 20-m shuttle run fitness test. If more than 100 children were eligible in a village, participants were to be randomly selected. Data collected on participants: Demographic data on age and sex was collected from each participant. Up to three stool samples were collected from each individual on separate days in each study year. Stool samples were processed using the Kato-Katz stool exam to get data on prevalence and infection intensity of Schistosoma mansoni and on three soil-transmitted helminths (Ascaris, Trichuris and hookworm). A blood sample was collected for hemoglobin assessment. Data was collected on anthropometric measurements, a physical fitness test, quality of life questionnaire, and abdominal ultrasonography. ClinEpiDB Data Integration: Data files were provided to ClinEpiDB as cleaned .csv files with all personal identifiers removed. All dates were obfuscated per individual through the application of a random number algorithm that shifted dates no more than seven days to comply with the ethical conduct of human subjects research. Acknowledgements: We thank the local administration, the assistant chiefs and village heads, and community health workers and school health teachers for help with community mobilization at all study sites. Financial Support: SCORE is funded by the Bill & Melinda Gates Foundation through a grant to the University of Georgia Research Foundation (UGARF). Ethics Statement: Written informed consent for participants in the Gaining and Sustaining Control studies was obtained from adults (including parents/legal guardians of children in the study) and assent was obtained from children less than 18 years old, except in places where village-level consent is the standard, in which case local requirements were met. Ethical review of research protocol was implemented by the human subjects committee in each African country and by the institutional review board (IRB) of their respective northern partners. The trials have been registered with the International Standard Randomized Controlled Trial registry under 16755535 (Kenya), and 95819193 (Tanzania). Last Updated: March 8, 2021Multi-country, cluster-randomized trials compared the effectiveness of community-wide and school-based treatment regimens on prevalence and intensity of schistosomiasis. To assess the impact of two different treatment schedules on S. mansoni-associated morbidity in children, cohort studies were nested within the randomized trials conducted in villages in Kenya and Tanzania. These cohort studies used selected markers to monitor changes in a suite of schistosomiasis disease outcomes.