August 12, 2025
We know that diarrheal disease is greatly reduced in communities with robust water, sanitation, and hygiene (WASH) infrastructure, with mutually reinforcing levels of community and individual protection. However, many large-scale trials have reported less-than-expected or null results for the efficacy of WASH interventions. Our work aims to mechanistically evaluate the possible reasons underlying suboptimal reductions in diarrhea among intervention households in a large RCT in Bangladesh, using simulations to estimate the trial results might have under different circumstances. Main takeaway: By factoring in local conditions, we can better understand why some WASH trials don’t show the expected results and design future efforts to be more effective.
