WASH Interventions in Disease Outbreak Response

Executive Summary

This evidence synthesis, commissioned by the Humanitarian Evidence Programme and carried out by a team from the Civil and Environmental Engineering Department of Tufts University, identifies, synthesizes and evaluates existing evidence of the impacts of water, sanitation and hygiene (WASH) interventions in disease outbreaks in 51 humanitarian contexts in 19 low and middle-income countries (LMICs).

What are water, sanitation and hygiene (WASH) interventions?

WASH interventions are commonly implemented as part of emergency response activities (i.e. in response to disease outbreaks) in LMICs. WASH interventions are provided to large populations to reduce the risk of disease transmission in a variety of settings. This synthesis focuses on WASH interventions targeted at populations affected by cholera, Ebola virus disease (hereafter ‘Ebola’), hepatitis E, hepatitis A, typhoid, acute watery diarrhoea and bacillary shigellosis (dysentery).

The review focuses on the following 10 WASH interventions:

1. well disinfection

2. source-based water treatment

3. household water treatment (HWT) – chlorine-based products

4. HWT – other products

5. community-driven sanitation

6. hygiene promotion

7. social mobilization

8. hygiene kit distribution

9. environmental hygiene

10. WASH package

‘Outbreaks’ are defined as follows, in accordance with World Health Organization (WHO) guidelines (WHO, 2016b):  the occurrence of disease in excess of the normal baseline (two times the baseline) or a sudden spike in cases (two times the incidence of new cases)  a single case of a communicable disease long absent from a population, or caused by a pathogen not previously recognized in that community or area  emergence of a previously unknown disease  a single case of particular diseases of interest (cholera, Ebola and hepatitis E).