Background: Soil-Transmitted Helminths (STHs) and schistosomes have been major public health problems in tropical and sub-tropical developing countries. School-age and preschool children are predominantly affected by soil-transmitted helminths and schistosomes. Parasite infections may cause micronutrient deficiency that results in anemia, growth retardation, and impaired cognitive development among children.

Objective: This study aimed to determine the prevalence and associated factors of soil-transmitted helminths and schistosomes among school-aged children.

Methods: A community-based cross-sectional study was conducted among 307 school-age children in West Ethiopia. Data regarding associated factors was collected through face-to-face interviews using a structured questionnaire. The stool specimen was examined for the existence of parasitic agents according to standard operating procedures. The data was entered into Epi-Data version3.1 and then exported to SPSS version 22 for analysis. Bivariate and multivariable logistic regressions were computed. Variables with a p ≤ 0.25 on the bivariate analysis were candidates for the multivariable analysis. The significance of the association was declared by a 95% confidence interval of AOR and a p < 0.05 in the multivariate model.

Result: A total of 307 stool samples were collected from school-age children who were included in the study. This study's results showed that the prevalence of intestinal parasitic infections was 40.4%. The most predominant intestinal parasitic infections were Ascaris lumbricoid (38.7%), followed by Hookworm (27.4%), and Trichuris trichiura (26.6%). Not handwashing after toilet (AOR = 2.19,95% (1.27-4.63) p = 0.025), eating unwashed fruits (AOR = 2.28,95% CI(1.209-4.29) p = 0.011), unclean fingernails (AOR = 2.38,95% CI(1.20-4.54), p = 0.013), eating street food (AOR = 2.98,95%CI (1.809-6.37, p = 0.001), unprotected water source (AOR = 2.87,95% CI(1.47) p = 5.56) (p = 0.002) and poor knowledge about the ways of transmission of IPIs (AOR = 2.28, 95% CI(1.01-5.12), p = 0.046) were found to be significantly associated with intestinal parasitic infections.

Conclusion: This study findings revealed a high prevalence of multiple parasitic infections that need annual mass deworming. This study called for mass drug administration, the provision of clean water supplies, scaling sanitation and hygiene, and health education.