The acronym WASH stands for Water, Sanitation and Hygiene. Interventions to improve WASH are associated with a lower risk of childhood diarrhea in low- and middle-income countries, Wolf et al. write in their paper. the Lancet.
Examples of WASH interventions include filtering drinking water at the point of use, providing improved sources and creating basic sanitation facilities with sewer connections. Until recently, it was unclear exactly how effective different WASH interventions are in reducing childhood diarrhea. An international research group therefore aimed to update previous reviews on this subject. To do this, they searched the MEDLINE, Embase, Scopus, Cochrane Library, and BIOSIS Citation Index databases and selected all controlled trials, both randomized and non-randomized, with categories for WASH exposure. Using random-effects models for meta-analysis and meta-regression, they then calculated pooled relative risks (RRs).
A total of 124 studies on 19,837 children could be included; 83 studies compared the provision of drinking water (62,616 children), 20 sanitation (40,799 children) and 41 hygiene (98,416 children). Compared to untreated water from an unimproved source, the risk of diarrhea was up to 50% lower when the water was treated at the time of use, for example by filtration (n = 23 studies; RR 0.50; 95% CI 0.41- 0.60), and higher drinking water quality from an improved source resulted in a 52% lower risk of diarrhea (n = 2; RR 0.48; 95% CI 0.26-0.87).
Sanitary interventions associated with a lower risk of diarrhea were the establishment of a sewer connection (n = 5; RR 0.53; 95% CI 0.30-0.93) and the promotion of hand washing with soap (RR 0 .70, 95% CI 0.64-0.76).
Bron:
Wolf J, Hubbard S, Brauer M, et al. Effectiveness of interventions to improve drinking water, sanitation, and handwashing with soap on risk of diarrhoeal disease in children in low-income and middle-income settings: a systematic review and meta-analysis. Lancet. 2022;400:48-59.