Crump John A, Sulka Alana C, Langer Adam J, Schaben Chad, Crielly Anita S, Gage Robert, Baysinger Michael, Moll Maria, Withers Gisela, Toney Denise M, Hunter Susan B, Hoekstra R Michael, Wong Stephanie K, Griffin Patricia M, Van Gilder Thomas J
Epidemic Intelligence Service, Division of Applied Public Health Training, Epidemiology Program Office, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta 30333, USA.
N Engl J Med. 2002 Aug 22;347(8):555-60. doi: 10.1056/NEJMoa020524.
Outbreaks of Escherichia coli O157:H7 infections have involved direct transmission from animals and their environment to humans. We describe an outbreak among visitors to a Pennsylvania dairy and petting farm that provides public access to animals.
We conducted both a case-control study among visitors to a farm to identify risk factors for infection and a household survey to determine the rates of diarrheal illness among these visitors. We performed an extensive environmental study to identify sources of E. coli O157:H7 on the farm.
Fifty-one patients with confirmed or suspected E. coli O157:H7 infection were enrolled in the case-control study. The median age of the patients was four years, and the hemolytic-uremic syndrome developed in eight. Contact with calves and their environment was associated with an increased risk of infection, whereas hand washing was protective. The household survey indicated that visitors to the farm during the outbreak had higher than expected rates of diarrhea. Environmental studies showed that 28 of the 216 cattle on the farm (13 percent) were colonized with E. coli O157:H7 that had the same distinct pattern on pulsed-field gel electrophoresis that was found in isolates from the patients. This organism was also recovered from surfaces that were accessible to the public.
In a large outbreak of E. coli O157:H7 infections among visitors to a dairy farm, predominantly children, high rates of carriage of E. coli O157:H7 among calves and young cattle most likely resulted in contamination of both the animals' hides and the environment.
大肠杆菌O157:H7感染的暴发涉及从动物及其环境直接传播给人类。我们描述了宾夕法尼亚州一家奶牛场和宠物农场暴发的疫情，该农场向公众开放供其接触动物。
我们对农场的访客进行了病例对照研究，以确定感染的危险因素，并进行了家庭调查，以确定这些访客的腹泻病发病率。我们进行了广泛的环境研究，以确定农场中大肠杆菌O157:H7的来源。
51例确诊或疑似大肠杆菌O157:H7感染的患者纳入病例对照研究。患者的中位年龄为4岁，8例发生了溶血尿毒综合征。与小牛及其环境接触会增加感染风险，而洗手则具有保护作用。家庭调查表明，疫情暴发期间农场的访客腹泻发病率高于预期。环境研究显示，农场216头牛中有28头（13%）携带大肠杆菌O157:H7，其脉冲场凝胶电泳图谱与患者分离株中发现的图谱相同。这种细菌也从公众可接触的表面分离出来。
在一家奶牛场访客中发生的大规模大肠杆菌O157:H7感染暴发中，主要是儿童，小牛和幼牛中大肠杆菌O157:H7的高携带率很可能导致动物皮毛和环境受到污染。
