December 12th, 2017
Objective: To compare the effect on prevalence of diarrhea and mortality of household based treatment of drinking water with flocculant-disinfectant, sodium hypochlorite, and standard practices in areas with turbid water source inAfrica. Design: Cluster randomized controlled trial over 20 weeks. Setting: Family compounds, each containing several houses, in rural western Kenya. Participants: 6650 people in 605 family compounds. Intervention: Water treatment: flocculant-disinfectant, sodium hypochlorite, and usual practice (control). Main outcome measures: Prevalence of diarrhea and all cause mortality. Escherichia coli concentration, free residual chlorine concentration, and turbidity in household drinking water as surrogates for effectiveness of water treatment. Results: In children <2 years old, compared with those in the control compounds, the absolute difference in prevalence of diarrhea was ?25% in the flocculant-disinfectant arm (95% confidence interval ?40 to ?5) and ?17% in the sodium hypochlorite arm (?34 to 4). In all age groups compared with control, the absolute difference in prevalence was ?19% in the flocculant-disinfectant arm (?34 to ?2) and ?26% in the sodium hypochlorite arm (?39 to ?9). There were significantly fewer deaths in the intervention compounds than in the control compounds (relative risk of death 0.58, P=0.036). Fourteen percent of water samples from control compounds had E coli concentrations <1 CFU/100 ml compared with 82% in flocculant-disinfectant and 78% in sodium hypochlorite compounds. The mean turbidity of drinking water was 8 nephelometric turbidity units (NTU) in flocculant-disinfectant households, compared with 55 NTU in the two other compounds (P<0.001). Conclusions: In areas of turbid water, flocculant-disinfectant was associated with a significant reduction in diarrhea among children <2 years. This health benefit, combined with a significant reduction in turbidity, suggests that the flocculant-disinfectant is well suited to areas with highly contaminated and turbid water.