Risebro Helen L, Doria Miguel F, Andersson Yvonne, Medema Gertjan, Osborn Keith, Schlosser Olivier, Hunter Paul R
School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, NR4 7TJ, UK.
J Water Health. 2007;5 Suppl 1:1-18. doi: 10.2166/wh.2007.136.
Prevention and containment of outbreaks requires examination of the contribution and interrelation of outbreak causative events. An outbreak fault tree was developed and applied to 61 enteric outbreaks related to public drinking water supplies in the EU. A mean of 3.25 causative events per outbreak were identified; each event was assigned a score based on percentage contribution per outbreak. Source and treatment system causative events often occurred concurrently (in 34 outbreaks). Distribution system causative events occurred less frequently (19 outbreaks) but were often solitary events contributing heavily towards the outbreak (a mean % score of 87.42). Livestock and rainfall in the catchment with no/inadequate filtration of water sources contributed concurrently to 11 of 31 Cryptosporidium outbreaks. Of the 23 protozoan outbreaks experiencing at least one treatment causative event, 90% of these events were filtration deficiencies; by contrast, for bacterial, viral, gastroenteritis and mixed pathogen outbreaks, 75% of treatment events were disinfection deficiencies. Roughly equal numbers of groundwater and surface water outbreaks experienced at least one treatment causative event (18 and 17 outbreaks, respectively). Retrospective analysis of multiple outbreaks of enteric disease can be used to inform outbreak investigations, facilitate corrective measures, and further develop multi-barrier approaches.
预防和控制疫情爆发需要审视疫情爆发起因事件的作用及相互关系。构建了一个疫情爆发故障树，并将其应用于欧盟61起与公共饮用水供应相关的肠道疫情。每起疫情平均确定了3.25个起因事件；每个事件根据其在每起疫情中的贡献百分比进行评分。水源和处理系统起因事件经常同时发生（34起疫情）。配水系统起因事件发生频率较低（19起疫情），但往往是对疫情贡献很大的孤立事件（平均百分比评分为87.42）。集水区内的牲畜和降雨，以及水源过滤不足或未过滤，共同导致了31起隐孢子虫疫情中的11起。在经历至少一次处理起因事件的23起原生动物疫情中，这些事件的90%是过滤不足；相比之下，对于细菌、病毒、肠胃炎和混合病原体疫情，75%的处理事件是消毒不足。地下水和地表水引发的疫情中，经历至少一次处理起因事件的数量大致相等（分别为18起和17起）。对多起肠道疾病疫情进行回顾性分析，可用于为疫情调查提供信息、促进采取纠正措施，并进一步完善多屏障方法。
