Department of Infectious Diseases, Public Health Service South Limburg, 6160 HA Geleen, The Netherlands.
J Clin Virol. 2010 Mar;47(3):268-72. doi: 10.1016/j.jcv.2009.12.002. Epub 2010 Jan 6.
A cross-border gastroenteritis outbreak at a scouting camp was associated with drinking water from a farmer's well.
A retrospective cohort study was performed to identify size and source of the outbreak, as well as other characteristics.
Epidemiological investigation included standardized questionnaires about sex, age, risk exposures, illness and family members. Stool and water (100mL) samples were analyzed for bacteria, viruses and parasites.
Questionnaires were returned by 84 scouts (response rate 82%), mean age of 13 years. The primary attack rate was 85% (diarrhoea and/or vomiting). Drinking water was the strongest independent risk factor showing a dose-response effect with 50%, 75%, 75%, 93% and 96% case prevalence for 0, 1, 2-3, 4-5 and >5 glasses consumed, respectively. Norovirus (GI.2 Southampton and GII.7 Leeds) was detected in 51 stool specimens (75%) from ill scouts. Water analysis showed fecal contamination, but no norovirus. The secondary attack rate was 20%.
This remarkable outbreak was caused by a point-source infection with two genogroups of noroviruses most likely transmitted by drinking water from a well. Finding a dose-response relationship was striking. Specific measures to reduce the risk of waterborne diseases, outbreak investigation and a good international public health network are important.
一个露营地发生了一起跨国肠胃炎暴发疫情，与饮用一位农民的井水有关。
通过回顾性队列研究，确定疫情的规模和来源以及其他特征。
流行病学调查包括有关性别、年龄、风险暴露、疾病和家庭成员的标准化问卷。对粪便和水（100mL）样本进行细菌、病毒和寄生虫分析。
共有 84 名童子军（应答率 82%）返回了调查问卷，平均年龄为 13 岁。主要攻击率为 85%（腹泻和/或呕吐）。饮用水是最强的独立风险因素，饮用 0、1、2-3、4-5 和 >5 杯水的病例患病率分别为 50%、75%、75%、93%和 96%，呈剂量反应关系。在 51 份患病童子军的粪便样本中（75%）检测到诺如病毒（GI.2 Southampton 和 GII.7 Leeds）。水样分析显示粪便污染，但未检测到诺如病毒。二级攻击率为 20%。
此次暴发疫情是由水源性感染引起的，最有可能是通过饮用井水传播的两种诺如病毒基因型引起的。发现剂量反应关系非常显著。减少水源性疾病风险的具体措施、疫情调查和良好的国际公共卫生网络非常重要。
