Water, sanitation and hygiene interventions to combat childhood diarrhoea in developing countries

This report is a synthetic review of impact evaluations examining effectiveness of water, sanitation and hygiene (WSH) interventions in reducing childhood diarrhoea. The results challenge the notion that water quality treatment in the household and hygiene interventions are necessarily the most efficacious and sustainable interventions for promoting reduction of diarrhoea. While point-of-use water quality interventions appear to be highly effective, much of the evidence is from trials conducted over small populations and short time periods. Hygiene interventions, particularly provision of soap for hand-washing, are effective in reducing diarrhoea morbidity. The analysis suggests that sanitation ‘hardware’ interventions are also highly effective. However, relatively few studies have been conducted in this area to-date. Evidence on the combined impact of multiple interventions is mixed. The study highlights the importance of behavioural factors in determining up-take and sustainable adoption of WSH technologies. Insights from diffusion theory suggest that preventive interventions tend to be adopted more slowly as benefits are difficult to observe and users presumably discontinue treatment as they perceive that the costs of using the intervention outweigh the benefits.