Hilborn E D, Mermin J H, Mshar P A, Hadler J L, Voetsch A, Wojtkunski C, Swartz M, Mshar R, Lambert-Fair M A, Farrar J A, Glynn M K, Slutsker L
Epidemiology Program Office, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Arch Intern Med. 1999;159(15):1758-64. doi: 10.1001/archinte.159.15.1758.
An outbreak of Escherichia coli O157:H7 infections in Connecticut and Illinois during May 28 to June 27, 1996, was investigated to determine the source of infections.
Independent case-control studies were performed in both states. Pulsed-field gel electrophoresis (PFGE) was performed on E. coli O157:H7 isolates. A case-patient was defined as a Connecticut or northern Illinois resident with diarrhea whose stool culture yielded E. coli O157:H7 of the outbreak-associated PFGE subtype. Controls were town-, age-, and sex-matched to case-patients. We traced implicated lettuce to the farm level and performed environmental investigations to identify unsafe lettuce production practices.
In Connecticut and Illinois, infection was associated with consumption of mesclun lettuce (Connecticut matched odds ratio [MOR], undefined; 95% confidence interval [CI], 3.4 to infinity; and Illinois MOR, undefined; 95% CI, 1.4 to infinity). We traced implicated lettuce to a single grower-processor. Cattle, a known E. coli O157:H7 reservoir, were found near the lettuce fields. Escherichia coli (an indicator of fecal contamination) was cultured from wash water and finished lettuce. A trace-forward investigation identified 3 additional states that received implicated lettuce; E. coli O157:H7 isolates from patients in 1 of these states matched the outbreak-associated PFGE subtype.
This multistate outbreak of E. coli O157:H7 infections was associated with consumption of mesclun lettuce from a single producer. Molecular subtyping facilitated the epidemiological investigation. This investigation increased the knowledge about current production practices that may contribute to the contamination of lettuce by microbial pathogens. Lettuce production practices should be monitored for microbiological safety.
对1996年5月28日至6月27日在康涅狄格州和伊利诺伊州爆发的大肠杆菌O157:H7感染事件进行了调查，以确定感染源。
在两个州都开展了独立的病例对照研究。对大肠杆菌O157:H7分离株进行了脉冲场凝胶电泳（PFGE）分析。病例患者定义为康涅狄格州或伊利诺伊州北部有腹泻症状且粪便培养出与此次疫情相关的PFGE亚型大肠杆菌O157:H7的居民。对照与病例患者在城镇、年龄和性别上相匹配。我们将受牵连的生菜追溯到农场层面，并进行了环境调查，以确定不安全的生菜生产做法。
在康涅狄格州和伊利诺伊州，感染与食用混合生菜有关（康涅狄格州匹配比值比[MOR]，未定义；95%置信区间[CI]，3.4至无穷大；伊利诺伊州MOR，未定义；95%CI，1.4至无穷大）。我们将受牵连的生菜追溯到了一个单一的种植加工商。在生菜田附近发现了作为已知大肠杆菌O157:H7宿主的牛。从冲洗水和成品生菜中培养出了大肠杆菌（粪便污染的指示菌）。一项向前追踪调查确定了另外3个接收了受牵连生菜的州；其中1个州患者的大肠杆菌O157:H7分离株与此次疫情相关的PFGE亚型匹配。
这次多州爆发的大肠杆菌O157:H7感染与食用来自单一生产商的混合生菜有关。分子分型有助于流行病学调查。这次调查增加了对当前可能导致生菜被微生物病原体污染的生产做法的了解。生菜生产做法应接受微生物安全性监测。
