What factors impact the effectiveness of emergency WASH interventions?

The numbers of people affected by natural disasters, disease outbreaks and conflict are on the rise. Water, sanitation and hygiene (WASH) interventions in emergency contexts have been shown to help reduce the risk of disease by providing safe water, reducing open defecation and promoting good hygiene practices. However, the evidence is limited, forcing responders to rely on past experiences or extrapolate evidence from development settings.