Household Water Chlorination Reduces Incidence of Diarrhea among Under-Five Children in Rural Ethiopia: A Cluster Randomized Controlled Trial

BackgroundHousehold water treatment has been advocated as a means of decreasing the burden of diarrheal diseases among young children in areas where piped and treated water is not available. However, its effect size, the target population that benefit from the intervention, and its acceptability especially in rural population is yet to be determined. The objective of the study was to assess the effectiveness of household water chlorination in reducing incidence of diarrhea among children under-five years of age.MethodA cluster randomized community trial was conducted in 36 rural neighborhoods of Eastern Ethiopia. Households with at least one child under-five years of age were included in the study. The study compared diarrhea incidence among children who received sodium hypochlorite (liquid bleach) for household water treatment and children who did not receive the water treatment. Generalized Estimation Equation model was used to compute adjusted incidence rate ratio and the corresponding 95% confidence interval.ResultIn this study, the incidence of diarrhea was 4.5 episodes/100 person week observations in the intervention arm compared to 10.4 episodes/100 person week observations in the control arm. A statistically significant reduction in incidence of diarrhea was observed in the intervention group compared to the control (Adjusted IRR = 0.42, 95% CI 0.36–0.48).ConclusionExpanding access to household water chlorination can help to substantially reduce child morbidity and achieve millennium development goal until reliable access to safe water is achieved.Trial RegistrationClinicalTrials.gov NCT01376440

研究背景：在缺乏集中式供水与净化水供应的地区，家庭水处理被倡导为减轻幼儿腹泻疾病负担的有效手段。然而，其干预效应量、受益目标人群，尤其是农村人群对该措施的接受度，仍有待明确。本研究旨在评估家庭饮水氯化法对降低5岁以下儿童腹泻发病率的效果。
研究方法：本研究在埃塞俄比亚东部的36个农村社区开展整群随机社区试验。纳入标准为家中至少有1名5岁以下儿童的家庭。研究对比了使用次氯酸钠（sodium hypochlorite，液态漂白剂）进行家庭水处理的儿童与未进行水处理的儿童的腹泻发病率。本研究采用广义估计方程（Generalized Estimation Equation, GEE）模型计算校正发病率比（adjusted incidence rate ratio, IRR）及其对应的95%置信区间（confidence interval, CI）。
研究结果：本研究中，干预组的腹泻发病率为每100人周4.5例发作，对照组则为每100人周10.4例发作。与对照组相比，干预组的腹泻发病率出现了具有统计学意义的降低（校正IRR=0.42，95%CI 0.36~0.48）。
研究结论：在可靠获取安全供水得以实现之前，推广家庭饮水氯化法可显著降低儿童发病率，助力实现千年发展目标（Millennium Development Goal）。
试验注册：ClinicalTrials.gov NCT01376440