Effectiveness and sustainability of water, sanitation, and hygiene interventions in combating diarrhoea

This paper presents a synthetic review of impact evaluations examining effectiveness of water, sanitation, and hygiene interventions in reducing diarrhoea among children. The evaluations were conducted in 35 low- and middle-income countries during the past three decades. The paper challenges the existing consensus that water treatment at point-of-use and hygiene interventions are necessarily the most effective and sustainable interventions for promoting reduction of diarrhoea. The analysis suggests that sanitation ‘hardware’ interventions are highly effective in reducing diarrhoea morbidity. Moreover, while there is a wealth of trials documenting the effectiveness of water treatment interventions, studies conducted over longer periods tend to show smaller effectiveness and evidence suggests compliance rates and therefore impact may fall markedly over time.