Association between household water treatment practices and diarrhea among children under five in Rwanda: a cross-sectional analysis of the 2019-20 Demographic and Health Survey

Background Diarrhea is a leading cause of illness and death in children under five years. Household water treatment is widely promoted, but national evidence from Rwanda on its association with diarrhea is limited. We studied this association, identified other factors linked to diarrhea, and described differences across provinces and districts. Methods We analyzed the 2019-20 Rwanda Demographic and Health Survey (7756 children under five; weighted number 7978). Caregivers reported diarrhea in the two weeks before the survey. Water treatment meant any reported treatment of drinking water. We used weighted prevalence, chi-square tests and weighted multivariable logistic regression to estimate adjusted odds ratios (AOR) with 95% confidence intervals (CI), and we estimated odds ratios by province. Results Diarrhea prevalence was 14.3%, and 33.0% of children lived in households that treated drinking water. Diarrhea was less common with water treatment (13.1% versus 14.9%, P = 0.031), but not after adjustment (AOR 1.02, 95% CI 0.87 to 1.20). Soap at the handwashing place was linked to lower odds (AOR 0.75, 95% CI 0.63 to 0.89), but the estimate was weaker in a model that also adjusted for province (AOR 0.82, 95% CI 0.67 to 1.01). Odds were higher at age 12 to 23 months than under 12 months (AOR 2.09, 95% CI 1.66 to 2.61), and for children of mothers with no education than with higher education (AOR 2.67, 95% CI 1.32 to 5.37). Prevalence ranged from 11.4% in the Eastern Province to 18.6% in the Western Province. Water treatment was linked to lower odds of diarrhea only in Kigali City (odds ratio 0.56, 95% CI 0.36 to 0.85) and the Southern Province (odds ratio 0.66, 95% CI 0.48 to 0.92). Conclusions Household water treatment was not independently associated with diarrhea among children under five in Rwanda, although results differed by province. Child age, maternal education and handwashing materials were more closely linked to diarrhea. Programs should combine water treatment with handwashing promotion and support for maternal education. Cross-sectional, self-reported data limit causal inference. Trial registration: Not applicable.