Keene W E, Hedberg K, Herriott D E, Hancock D D, McKay R W, Barrett T J, Fleming D W
Acute and Communicable Disease Section, Oregon Health Division, Portland 97232, USA.
J Infect Dis. 1997 Sep;176(3):815-8. doi: 10.1086/517310.
A protracted outbreak of Escherichia coli O157:H7 infections was caused by consumption of unpasteurized ("raw") milk sold at Oregon grocery stores. Although it never caused a noticeable increase in reported infections, the outbreak was recognized because of routine follow-up interviews. Six of 16 Portland-area cases reported between December 1992 and April 1993 involved people who drank raw milk from dairy A. By pulsed-field gel electrophoresis (PFGE), E. coli O157:H7 isolates from these cases and from the dairy A herd were homologous (initially, 4 of 132 animals were E. coli O157:H7-positive). Despite public warnings, new labeling requirements, and increased monitoring of dairy A, retail sales and dairy-associated infections continued until June 1994 (a total of 14 primary cases). Seven distinguishable PFGE patterns in 3 homology groups were identified among patient and dairy herd E. coli O157:H7 isolates. Without restrictions on distribution, E. coli O157:H7 outbreaks caused by raw milk consumption can continue indefinitely, with infections occurring intermittently and unpredictably.
俄勒冈州杂货店售卖的未经巴氏杀菌的（“生”）牛奶导致了大肠杆菌O157:H7感染的持续爆发。尽管此次爆发并未导致报告感染病例显著增加，但由于进行了常规随访访谈，该疫情得以被发现。1992年12月至1993年4月期间报告的波特兰地区16例病例中，有6例涉及饮用了A奶牛场生牛奶的人群。通过脉冲场凝胶电泳（PFGE）分析，这些病例以及A奶牛场畜群中的大肠杆菌O157:H7分离株具有同源性（最初，132头动物中有4头大肠杆菌O157:H7呈阳性）。尽管已发布公开警告、实施新的标签要求并加强了对A奶牛场的监测，但零售销售以及与奶牛场相关的感染一直持续到1994年6月（共14例主要病例）。在患者和奶牛场畜群的大肠杆菌O157:H7分离株中，鉴定出了3个同源组中的7种可区分的PFGE模式。如果不对销售加以限制，由饮用生牛奶导致的大肠杆菌O157:H7疫情可能会无限期持续，感染会间歇性且不可预测地发生。
