Endemically acquired foodborne outbreak of enterotoxin-producing Escherichia coli serotype O169:H41

Enterotoxigenic Escherichia coli (ETEC) is traditionally recognized as a common cause of traveler's diarrhea, but is becoming a more frequent cause of foodborne disease outbreaks in the United States. It is important for public health practitioners and clinicians to be aware of ETEC as a domestic cause of gastroenteritis. We investigated a foodborne disease outbreak to understand the epidemiology of ETEC in this setting.

We conducted a cohort study of 63 employees of Company A. A case was defined as an employee who experienced diarrhea or vomiting or fever and cramps after eating a catered meal at Company A from August 14th-15th. A standardized questionnaire was administered to cases and controls.

Of 63 employees, 36 met the case definition (Attack Rate = 57.1%). Diarrhea (94%) and cramps (74%) were common, whereas vomiting was not (3%). Mean duration of illness was 2.7 days. Coleslaw at the August 15th lunch was significantly associated with illness (Odds ratio = 4.4, 95% CI = 1.1-17). Stool specimens were positive for heat-stable enterotoxin-producing E. coli O169:H41. Contamination likely occurred at the point of service.

This outbreak illustrates the changing epidemiology of enterotoxigenic E. coli and the importance for healthcare practitioners to consider ETEC as a potential cause of domestically acquired gastroenteritis.