Better Existing Water, Sanitation, and Hygiene Can Reduce the Risk of Cholera in an Endemic Setting: Results From a Prospective Cohort Study From Kolkata, India

Abstract Background Global cholera control efforts rely heavily on effective water, sanitation, and hygiene (WASH) interventions in cholera-endemic settings. Methods Using data from a large, randomized controlled trial of oral cholera vaccine conducted in Kolkata, India, we evaluated whether natural variations in WASH in an urban slum setting were predictive of cholera risk. From the control population (n = 55 086), baseline WASH data from a randomly selected “training subpopulation” (n = 27 634) were analyzed with recursive partitioning to develop a dichotomous (“better” vs “not better”) composite household WASH variable from several WASH features collected at baseline, and this composite variable was then evaluated in a mutually exclusive “validation population” (n = 27 452). We then evaluated whether residents…