Prevalence of Soil-Transmitted Helminths and Schistosoma mansoni among Schoolchildren across Altitudinal Gradients in Amhara National Regional State, Ethiopia.

Soil-transmitted helminths (STHs) and Schistosoma mansoni infections are common parasitic infections in sub-Saharan Africa. Their distributions vary across altitudes in Ethiopia. Hence, ongoing updates of infection risk factors and prevalence data are necessary for successful intervention. A school-based, cross-sectional study was conducted from October to December 2019 involving 530 schoolchildren who were recruited by systematic random sampling from Amhara Regional State. A structured questionnaire was used to collect data on sociodemographic, geographical and environmental factors. Stool samples were collected and processed by Ritchie's and Kato Katz techniques. Data were entered into EpiData and analyzed using SPSS. Descriptive statistics were used to compute prevalence, and logistic regression was used to assess factors associated with STHs and S. mansoni infections. Variables with P < 0.05 were considered statistically significant. Among 530 schoolchildren, 169 (31.9%) and 78 (14.7%) were infected with STHs and S. mansoni, respectively. The prevalence of STHs (40.2%) in the semi-highlands and S. mansoni (30.4%) in the lowlands was high. Infrequent shoes wearing, exposure to soil, not washing vegetables before eating, and living outside in lowland areas were significantly associated with STHs infections (P < 0.05). Schoolchildren who fetched water to irrigate fields, swam in rivers, and lived in lowland areas were significantly associated with S. mansoni infection (P < 0.05). In conclusion, prevalence rates of STHs and S. mansoni infections differed across altitudes in Amhara Regional State. Therefore, current control strategies including deworming and provision of clean water and education on sanitation and hygiene should be intensified and adapted to the local context.