Effect of a Water Treatment and Hygiene Intervention on Household Drinking Water Quality and Diarrhoea: A Sub-study of the TISA Trial in Senegal

Severe acute malnutrition (SAM) affects an estimated 17 million children globally and is increasingly treated at home under the Community-based Management of Acute Malnutrition (CMAM) approach. However, household environmental hazards, particularly unsafe drinking water, may undermine recovery. In the Traitement Intégré de la Sous-Nutrition Aiguë (TISA) cluster-randomised controlled trial in northern Senegal, children aged 6–59 months with uncomplicated SAM were enrolled in outpatient therapeutic programmes. The control group received the standard eight-week national protocol, while the intervention group also received chlorination tablets, a 20-litre storage container, soap, and hygiene promotion. This nested sub-study assessed the impact of the intervention on household water quality and diarrhoea. Among 445 households, drinking water samples collected 4–6 weeks after enrolment showed higher median free chlorine in the intervention group (0.5 mg/L, IQR 0.1–2.0) than controls (0.1 mg/L, IQR 0.1–0.1). Escherichia coli contamination was reduced, with 46% of intervention samples classified as safe (<1 CFU/100 mL) versus 34% in the control. Diarrhoea prevalence declined over time in both groups, with a significantly greater reduction in the intervention arm (global Wald test p=0.028). The intervention substantially improved microbial drinking-water quality and was associated with lower diarrhoea prevalence among children receiving SAM treatment, though residual water contamination remained at levels posing moderate health risk. These findings highlight the potential for integrating targeted water treatment and hygiene measures into CMAM to reduce waterborne disease risk and diarrhoea among children with SAM.