Department of Environmental Health, Faculty of Science, Tshwane University of Technology, Pretoria, South Africa.
Int J Hyg Environ Health. 2011 Mar;214(2):162-6. doi: 10.1016/j.ijheh.2010.10.005. Epub 2010 Dec 8.
There is still debate and uncertainty in the literature about the health benefits of community water supply interventions. This paper reports on a changing incidence of self-reported diarrhoea associated with the implementation of two community water supplies. We conducted prospective weekly recording of diarrhoeal disease in three communities. Two of the communities were scheduled to receive an improved water supply and one was expected to continue to rely on an unimproved source during the study period. Data of self-reported diarrhoea was collected from each participating household on a weekly basis for up to 56 weeks, of which some 17 weeks were prior to implementation of the new water supply systems. Data was modelled using Generalized Estimating Equations (GEE) to account for possible clustering within households and within villages. For the two intervention communities in the study, the incidence rate ratio (IRR) for all ages after the intervention was 0.43 (95% CI 0.24-0.79) when compared to the control community (who did not receive an intervention), implying a 57% reduction of diarrhoea. Both of the new water systems were unreliable, one not operating on 4 weeks and the other on 16 weeks. The more reliable of the two intervention systems was also associated with less illness than in the least reliable system (IRR=0.41, 95% CI 0.21-0.80). We also noted anecdotal reports that during supply failures in the new systems some people were starting to use household water treatment. The implementation of improved water systems does appear to have been associated with a reduction of diarrhoeal disease in the communities. However the health impact was most obvious in the community with the more reliable system. Further research needs to be done to determine whether public health gains from community water supply interventions can be leveraged by occasional use of household water treatment (HWT) during supply failures.
关于社区供水干预措施对健康的益处，文献中仍存在争议和不确定性。本文报告了与实施两项社区供水相关的自报腹泻发病率的变化情况。我们对三个社区进行了前瞻性的每周腹泻疾病记录。在研究期间，两个社区计划获得改良供水，而一个社区预计将继续依赖未经改良的水源。每个参与家庭每周都要对自我报告的腹泻数据进行收集，最长可达 56 周，其中约 17 周是在新供水系统实施之前。使用广义估计方程（GEE）对数据进行建模，以考虑到家庭内和村庄内可能存在的聚类。对于研究中的两个干预社区，与对照组（未接受干预的社区）相比，所有年龄段的发病率比（IRR）在干预后为 0.43（95%CI 0.24-0.79），这意味着腹泻减少了 57%。两个新的供水系统都不可靠，一个系统有 4 周无法运行，另一个系统有 16 周无法运行。两个干预系统中更可靠的系统与较少的疾病相关（IRR=0.41，95%CI 0.21-0.80）。我们还注意到一些传闻报告称，在新系统出现供应故障期间，一些人开始使用家庭水处理。改良供水系统的实施似乎确实与社区腹泻病的减少有关。然而，在系统更可靠的社区，健康影响最为明显。需要进一步研究，以确定在供应故障期间偶尔使用家庭水处理（HWT）是否可以利用社区供水干预措施带来的公共卫生收益。
