Water, sanitation and hygiene for the prevention of diarrhoea

Abstract

Background Ever since John Snow’s intervention on the Broad St pump, the effect of water quality, hygiene and sanitation in preventing diarrhoea deaths has always been debated. The evidence identified in previous reviews is of variable quality, and mostly relates to morbidity rather than mortality.Methods We drew on three systematic reviews, two of them for the Cochrane Collaboration, focussed on the effect of handwashing with soap on diarrhoea, of water quality improvement and of excreta disposal, respectively. The estimated effect on diarrhoea mortality was determined by applying the rules adopted for this supplement, where appropriate.Results The striking effect of handwashing with soap is consistent across various study designs and pathogens, though it depends on access to water. The effect of water treatment appears similarly large, but is not found in few blinded studies, suggesting that it may be partly due to the placebo effect. There is very little rigorous evidence for the health benefit of sanitation; four intervention studies were eventually identified, though they were all quasi-randomized, had morbidity as the outcome, and were in Chinese.Conclusion We propose diarrhoea risk reductions of 48, 17 and 36%, associated respectively, with handwashing with soap, improved water quality and excreta disposal as the estimates of effect for the LiST model. Most of the evidence is of poor quality. More trials are needed, but the evidence is nonetheless strong enough to support the provision of water supply, sanitation and hygiene for all.

On-plot drinking water supplies and health: A systematic review

“…They also have been shown to spend less time collecting water (Aiga and Umenai, 2002), use greater quantities of water (Bailey et al, 1991;Polack et al, 2006), and practice improved hygiene behavior (Cairncross and Cliff, 1987;Curtis et al, 1995). Health benefits of hygiene reflect the Mills Reincke phenomenon (Sedgwick and MacNutt, 1908) of multiple health gains; for example, hygiene has been shown to reduce risk and prevalence of respiratory infections (Ryan et al, 2001;Rabie and Curtis, 2006), trachoma (Taylor et al, 1989;West et al, 1995), and diarrhea (Aung Myo and Thein, 1989;Cairncross et al, 2010). Repeated episodes of diarrhea have adverse effects on nutrition and growth in children (Black et al, 1984;Checkley et al, 2003), and the use of improved water sources, defined as water sources protected from outside contamination (WHO/UNICEF, 2012), has been associated with improved child height and weight outcomes (Tomkins et al, 1978;Esrey et al, 1988).…”

Improved monitoring framework for local planning in the water, sanitation and hygiene sector: From data to decision-making

“…Diseases related to insufficient and unsafe drinking water, unimproved sanitation and poor hygiene education are common causes of illness and death (Cairncross et al, 2010;Esrey et al, 1991). In addition, the benefits of improved services provision are central to the cycle of disease and poverty, but they are rarely enjoyed by the most vulnerable (Cortinovis et al, 1993).…”

A community randomised controlled trial evaluating a home-based environmental intervention package of improved stoves, solar water disinfection and kitchen sinks in rural Peru: Rationale, trial design and baseline findings

“…They contribute effectively to the prevention of diarrhoeal diseases and the transmission of acute lower respiratory infection (ALRI) [7][8][9][10]. A recent systematic review provided evidence that hand washing with soap can reduce child diarrhoea by 48%, and the risk to acquire a diarrhoeal illness can be reduced by 17% and 36% through adequate household water treatments (HWT) and improved sanitation [11]. Similarly it has been shown that simple indoor air quality interventions reduce disease burden for ALRI [4].…”