WASH & STH Systematic Review

About

The second in this series of SHARE-funded studies exploring the impact of WASH on NTDs, this systematic review compiled and analysed evidence on relationship between WASH access or practices and STH infection.

STHs, parasitic worms – roundworm, hookworm, and whipworm – that live in the human intestine, mainly occur in (sub)tropical regions and are most common in developing countries where WASH is poor. Repeated infection with STHs leads to a heavy parasite infestation of the gut, causing chronic diarrhoea, intestinal bleeding, and abdominal pain. It can also lead to malnutrition, anaemia, stunting and slowing of mental development in children. 

Preventive chemotherapy represents a powerful short-term control strategy but, since humans are often re-infected rapidly, longer-term solutions (which include improvements in WASH) are required. However, as of 2013, the evidence for the association of improved WASH on STH infection had not been compiled in a systematic review.

This study addressed this evidence gap, finding that WASH access and practices are generally associated with reduced odds of STH infection. Although most WASH interventions for STH have to date focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection. It recommends that further research to determine the magnitude of benefit from WASH interventions for STH control is conducted and that multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts are adopted.