Effects of Single and Combined Water, Sanitation and Handwashing Interventions on Fecal Contamination in the Domestic Environment: A Cluster-Randomized Controlled Trial in Rural Bangladesh.

Andrew Mertens,Mir Alvee Ahmed,John M. Colford,Mir Himayet Kabir,Jade Benjamin-Chung,Ayse Ercumen,Pavani K. Ram,Stephen P. Luby,Thomas Clasen,Md. Masudur Rahman Khalil,Leanne Unicomb,Md. Sajjadur Rahman,Ashish Kumar,Alan E. Hubbard,Mahbubur Rahman,Benjamin F. Arnold,Sarker Masud Parvez

doi:10.1021/acs.est.8b05153

Abstract

Water, sanitation, and hygiene interventions have varying effectiveness in reducing fecal contamination in the domestic environment; delivering them in combination could yield synergies. We conducted environmental assessments within a randomized controlled trial in Bangladesh that implemented single and combined water treatment, sanitation, handwashing (WSH) and nutrition interventions (WASH Benefits, NCT01590095). After one and two years of intervention, we quantified fecal indicator bacteria in samples of drinking water (from source or storage), child hands, children’s food and sentinel objects. In households receiving single water treatment interventions, Escherichia coli prevalence in stored drinking water was reduced by 50% and concentration by 1-log. E. coli prevalence in food was reduced by 30% and concentration by 0.5-log in households receiving single water treatment and handwashing interventions. Combined WSH did not reduce fecal contamination more effectively than its components. Interventions did not reduce E. coli in groundwater, on child hands and on objects. These findings suggest that WSH improvements reduced contamination along the direct transmission pathways of stored water and food but not along indirect upstream pathways. Our findings support implementing water treatment and handwashing to reduce fecal exposure through water and food but provide no evidence that combining interventions further reduces exposure.

Highlights

Diarrheal disease transmission occurs through a complex web of environmentally mediated pathways including drinking water, food, hands, fomites, and vectors
Treating drinking water before consumption and washing hands with water and soap lower fecal contamination of drinking water and hands, respectively, and reduce reported diarrhea.[1−4] hands are rapidly recontaminated by contact with objects and surfaces[5−7] and treated water can be recontaminated by hands and utensils during storage.[8]
Of 2445 households selected for enteric dysfunction (EED) enrollment in year one, we enrolled 1980 (81%) in the environmental assessment between October 2013 and December 2014; we enrolled 181 water arm households and 366 handwashing arm households

Summary

Introduction

Diarrheal disease transmission occurs through a complex web of environmentally mediated pathways including drinking water, food, hands, fomites, and vectors.

Results

Conclusion