Paunio M, Pebody R, Keskimäki M, Kokki M, Ruutu P, Oinonen S, Vuotari V, Siitonen A, Lahti E, Leinikki P
University of Helsinki, Department of Public Health, Mannerheimintie, Finland.
Epidemiol Infect. 1999 Feb;122(1):1-5. doi: 10.1017/s0950268898001927.
In 1997 the first outbreak of Escherichia coli O157:H7 infections involving 14 cases occurred in Finland. A case was defined as a resident of Alavus with an episode of diarrhoea between 5 and 17 July 1997, and from whom E. coli O157:H7 was isolated from stool. The investigation included case searching and a population-based case control study. Five primary and eight symptomatic secondary cases of E. coli O157:H7 illness were detected. In the 10 days before the outbreak, all 5 primary patients (aged 3-8 years), but only 6 of 32 population controls from the same age range (Fisher's test, P < 0.001) and 4 of 10 sibling controls (P < 0.05) had visited (but had not necessarily bathed in) a shallow beach popular among young children. Four out of 5 primary cases had remained within 5 m of the beach while swimming and had swallowed lake water compared to 1 of 5 population controls. These analytical epidemiologic findings incriminated fresh lake water as the vehicle of E. coli O157:H7 transmission.
1997年，芬兰首次爆发了由14例感染大肠杆菌O157:H7引起的疫情。病例定义为1997年7月5日至17日期间在阿拉武斯居住且出现腹泻症状，并且粪便中分离出大肠杆菌O157:H7的患者。调查包括病例搜索和基于人群的病例对照研究。共检测到5例原发性和8例有症状的继发性大肠杆菌O157:H7病例。在疫情爆发前10天，所有5例原发性患者（年龄3至8岁），但同一年龄段的32名人群对照中只有6人（费舍尔检验，P < 0.001）以及10名同胞对照中的4人（P < 0.05）去过（但不一定在其中游泳）一个深受幼儿喜爱的浅滩。5例原发性病例中有4例在游泳时停留在距离浅滩5米范围内并吞咽了湖水，而5名人群对照中只有1人这样做。这些分析性流行病学研究结果表明，新鲜的湖水是大肠杆菌O157:H7传播的媒介。
