Tracing Strongyloides stercoralis transmission and risk factors from schoolchildren to household in Northwest Ethiopia

BACKGROUND: Strongyloides stercoralis is a neglected soil-transmitted helminth with a complex life cycle that enables both autoinfection and environmental transmission. Despite its public health importance, the burden and transmission dynamics of strongyloidiasis remain poorly understood in endemic settings such as Ethiopia, particularly at the household level. Hence, this study aimed to trace the transmission of S. stercoralis and associated factors from infected schoolchildren to their households in Northwest Ethiopia. METHODOLOGY: A school-based cross-sectional study was conducted from 2024 to 2025 in Northwest Ethiopia. A total of 273 schoolchildren were randomly selected from three schools and screened for S. stercoralis. Children who tested positive were considered index cases, and all consenting household members were subsequently screened. Stool samples were examined using Kato-Katz, the Baermann concentration technique, and agar plate culture. Data on socio-demographic characteristics and potential risk factors were collected using structured questionnaires. Bivariate and multivariable logistic regression analyses were performed to identify factors associated with infection. FINDINGS: Out of 273 school children screened, the prevalence of S. stercoralis was 22.7%. Among 80 household members examined, 71.3% were infected with S. stercoralis. School children who lived in houses with mud floors (AOR = 2.91; p = 0.019), had close contact with dogs (AOR = 2.54; p = 0.006), lived in areas with clay soil (AOR = 2.98; p = 0.036), participated in irrigation activities (AOR = 3.72; p = 0.008) and wore shoes (AOR = 3.67; p = 0.017) were significantly associated with S. stercoralis infection. CONCLUSIONS: This study demonstrates a substantial burden of S. stercoralis infection among schoolchildren and an exceptionally high prevalence among their household members. The findings underscore the importance of environmental, behavioral, and zoonotic factors in sustaining transmission. These results emphasize the urgent need for integrated control strategies to include household-level screening and treatment.