Can drinking water, sanitation, handwashing, and nutritional interventions reduce antibiotic use in young children?

Frequent antibiotic use in areas with high infection burdens can lead to antimicrobial resistance and microbiome alterations. Reducing pathogen exposure and child undernutrition can reduce infections and subsequent antibiotic use. We assessed effects of water, sanitation, handwashing (WSH) and nutrition interventions on pediatric antibiotic use in Bangladesh and Kenya, using longitudinal data from birth cohorts (at ages 3-28 months) enrolled in the WASH Benefits cluster-randomized trials. Over 50% of children used antibiotics at least once in the last 90 days. In Bangladesh, the prevalence of using antibiotics at least once was 10-14% lower in groups receiving WSH (prevalence ratio [PR]=0.90 (0.82-0.99)), nutrition (PR=0.86 (0.78-0.94)), and nutrition+WSH (PR=0.86 (0.79-0.93)) interventions. The prevalence of using antibiotics multiple times was 24-35% lower in intervention arms. Intervention effects were strongest when the birth cohort was younger. In Kenya, interventions did not affect antibiotic use. Improving WSH and nutrition can reduce antibiotic use in some low- and middle-income settings. Studies should assess whether such reductions translate to reduced carriage of antimicrobial resistance.