Am J Epidemiol. 2014 Feb 1;179(3):344-52. doi: 10.1093/aje/kwt279. Epub 2013 Nov 19.
The impact of heavy rainfall events on waterborne diarrheal diseases is uncertain. We conducted weekly, active surveillance for diarrhea in 19 villages in Ecuador from February 2004 to April 2007 in order to evaluate whether biophysical and social factors modify vulnerability to heavy rainfall events. A heavy rainfall event was defined as 24-hour rainfall exceeding the 90th percentile value (56 mm) in a given 7-day period within the study period. Mixed-effects Poisson regression was used to test the hypothesis that rainfall in the prior 8 weeks, water and sanitation conditions, and social cohesion modified the relationship between heavy rainfall events and diarrhea incidence. Heavy rainfall events were associated with increased diarrhea incidence following dry periods (incidence rate ratio = 1.39, 95% confidence interval: 1.03, 1.87) and decreased diarrhea incidence following wet periods (incidence rate ratio = 0.74, 95% confidence interval: 0.59, 0.92). Drinking water treatment reduced the deleterious impacts of heavy rainfall events following dry periods. Sanitation, hygiene, and social cohesion did not modify the relationship between heavy rainfall events and diarrhea. Heavy rainfall events appear to affect diarrhea incidence through contamination of drinking water, and they present the greatest health risks following periods of low rainfall. Interventions designed to increase drinking water treatment may reduce climate vulnerability.
强降雨事件对水传播腹泻病的影响尚不确定。为了评估生物物理和社会因素是否会改变对强降雨事件的脆弱性，我们在 2004 年 2 月至 2007 年 4 月期间在厄瓜多尔的 19 个村庄每周进行了主动腹泻监测。强降雨事件定义为研究期间内某一 7 天期间内 24 小时降雨量超过第 90 个百分位值（56 毫米）。我们使用混合效应泊松回归检验了以下假设：在之前的 8 周内降雨量、水和卫生条件以及社会凝聚力会改变强降雨事件与腹泻发病率之间的关系。在干旱期后，强降雨事件与腹泻发病率增加相关（发病率比=1.39，95%置信区间：1.03，1.87），在湿期后腹泻发病率降低（发病率比=0.74，95%置信区间：0.59，0.92）。饮用水处理减少了干旱期后强降雨事件的不利影响。卫生、卫生和社会凝聚力并没有改变强降雨事件与腹泻之间的关系。强降雨事件似乎通过饮用水污染影响腹泻发病率，并且在降雨量较低时期对健康构成最大风险。旨在增加饮用水处理的干预措施可能会降低气候脆弱性。
