Background: Soil-transmitted helminths (STHs) are parasitic worms that are widely distributed in the tropical and subtropical regions. In Ethiopia, one of the tropical countries, STH infections are high and cause a huge burden. Several STH species show a pattern of household clustering with regard to prevalence and intensity. However, there is a scarcity of data on the status of STH infection among family contacts of STH-infected individuals in Ethiopia in general and in the study area in particular.

Objective: This study is aimed at assessing the prevalence of soil-transmitted helminths and associated factors among STH-infected household contacts in Burie Zuria district, northwest Ethiopia.

Method: A community-based cross-sectional study was conducted among 422 study participants from March to May 2021. Study participants were traced to their residences by following STH-infected patients. A convenient sampling technique was used to recruit the study participants. The stool samples were processed using duplicate Kato-Katz thick smears and a modified Ritchie's technique. The data were entered and analyzed using the Statistical Package for Social Sciences, version 26 of the software package. A P value <0.05 was considered a statistically significant association.

Results: The overall prevalence of STHs was 36.5% (95% CI: 31.7%-41.5%). Two STHs, namely hookworm species (33.2%, 140/422) at (95% CI: 28.9%-37.8%) and Ascaris lumbricoides (4.3%, 18/422) at (95% CI: 2.7%-6.6%), were identified, with a double infection of 2.6% (4/154) at (95% CI: 1.0%-6.5%). Almost the majority (96.9%) of hookworm species and all Ascaris lumbricoides infections were categorized under a light intensity of infection. Family size >5 (AOR = 1.74; 95% CI: 1.15-2.60; P = 0.008) and lack of latrine facility (AOR = 1.86; 95% CI: 1.17-2.90; P = 0.02) were significantly associated with STH infections.

Conclusion: A high prevalence of hookworms was found in the study area, where the majority of the study participants were adults. This finding may provide a basis for revising the school-based deworming programs that exclude the adult population. Public health interventions like accessing latrines, health education, and deworming programs should be regularly implemented for all age groups in the areas.