WASH Benefits Research Objectives

The goal of the WASH Benefits study is to generate rigorous evidence about the impacts of sanitation, water quality, handwashing, and nutrition interventions on child health and development in the first years of life. The study is designed as two, highly comparable cluster randomized trials in rural Bangladesh and Kenya. In each country, the study has seven arms (6 treatment arms and a control arm).


The study has three primary scientific objectives:

• Measure the impact of sanitation, water quality, handwashing, and nutrition interventions on child health and development after 2 years of intervention.
• Determine whether there are larger reductions in diarrhea when providing a combined water, sanitation and handwashing intervention compared to each component alone.
• Determine whether there are larger effects on growth and development from combining a) daily supplemental nutrition with b) a combined water, sanitation and handwashing intervention compared to each component alone.

The study has three secondary scientific objectives:

• Measure the impact of nutritional supplements and household environmental interventions on environmental enteropathy biomarkers, and more clearly elucidate this potential pathway between environmental interventions and child growth and development.
• Measure the impact of sanitation, water quality, handwashing and nutritional interventions on intestinal parasitic infection prevalence and intensity.
• Measure the association between parasitic infection and other measures of enteric health, including acute diarrhea and environmental enteropathy biomarkers.

Measure the impact of sanitation, water quality, handwashing, and nutrition interventions on the following tertiary outcomes: 

• Weight-for-age at 1 and 2 years
• Weight-for-height at 1 and 2 years
• Underweight at 2 years
• Wasted at 2 years
• Severely stunted at 2 years
• Head circumference-for-age at 1 year and 2 years
• Soil-transmitted helminth infection at 2 years
• Protozoan infection at 2 years
• Verbal Communicative Development Inventory at 1 year
• WHO motor milestones at 1 year
• Acute respiratory illness
• All cause mortality 

To achieve these objectives, we will conduct a parallel, cluster-randomized controlled trial with 6 treatment arms and a double-sized control arm. The studies enrolled pregnant women in study villages and will measure outcomes following 12 and 24 months of intervention.