Prevalence of Intestinal Parasitic Infections and Associated Water, Sanitation, and Hygiene Risk Factors among School Children in Mwea Irrigation Scheme, Kirinyaga County, Kenya

School children bear a significant burden of intestinal parasitic infections. Because they spend most of their time at home and school, it is necessary to identify the key water, sanitation, and hygiene (WASH) factors associated with these infections in both environments. This was a cross-sectional survey conducted in Mwea West, Kirinyaga County. 180 primary school children aged 8-14 years were randomly selected from three schools (Mianya, Mbui Njeru, and Mukou primary schools). Questionnaires and checklists were administered and single stool samples were collected. Stool samples were microscopically examined for Schistosoma mansoni, soil-transmitted helminths, and protozoan infections. Data on WASH were obtained at home and school. The factors significantly associated with S. mansoni and intestinal protozoa infections in the school children were determined using univariable and multivariable logistic regression models reporting the odds ratio at 95% confidence intervals. The overall prevalence of S. mansoni and intestinal protozoa infections was 70.5% (95% CI: 59.1-84.3) and 32.7% (95% CI: 26.8-40.1), respectively. Only one case of STH (A. lumbricoides) was identified. The prevalence of coinfections of S. mansoni and intestinal protozoa infections was 22.8% (95% CI: 19.2-27.1). An increased prevalence of S. mansoni infection was associated with children above 12 years (aOR = 3.19, p=0.015), those in Mianya primary (aOR = 1.23, p=0.001), those in Mukou primary (aOR = 3.19, p=0.001), and reported behavior of wearing shoes at home (aOR = 1.67, p=0.010). However, handwashing behavior after defecation at home (aOR = 0.39, p=0.001) was protective against S. mansoni infection. For any protozoan infection, male children had increased odds of infection (aOR = 2.41, p=0.001) while use of wiping material (aOR = 0.55, p=0.019) and water contact (aOR = 0.32, p=0.001) was protective against intestinal protozoa infections. Infections with S. mansoni and any protozoa and their coinfection were present. Findings revealed that several hygiene factors were protective against infections while other were risk factors. Therefore, deworming should be complemented with behavior education on hygienic habits.