Herzig CT, Fleischauer AT, Lackey B, et al. Notes from the Field: Enteroinvasive Escherichia coli Outbreak Associated with a Potluck Party — North Carolina, June–July 2018. MMWR Morb Mortal Wkly Rep 2019;68:183–184. DOI: http://dx.doi.org/10.15585/mmwr.mm6807a5.

“On July 2, 2018, the North Carolina Division of Public Health was notified that approximately three dozen members of an ethnic Nepali refugee community had been transported to area hospitals for severe gastrointestinal illness after attending a potluck party on June 30. The North Carolina Division of Public Health partnered with the local health department and CDC to investigate the outbreak, identify the cause, and prevent further transmission. The investigation included molecular-guided laboratory testing of clinical specimens by CDC, which determined that this was the first confirmed U.S. outbreak of enteroinvasive Escherichia coli (EIEC) in 47 years.

A case was defined as the occurrence of diarrhea, vomiting, or fever ≥101°F (38.3°C) in a person who consumed food served at the party. Cases were identified through medical record review and retrospective cohort investigation with convenience sampling of party attendees. Among approximately 100 attendees, 52 met the case definition. Median age was 31 years (range = 3–76 years); 28 (54%) were hospitalized, including 13 (25%) with sepsis, and eight (15%) who were admitted to an intensive care unit. All patients recovered, and no secondary cases were identified.

Forty-nine persons, including 35 who were ill, were interviewed using a questionnaire to ascertain symptoms, recent travel, and food exposures. Participants also were provided with hand hygiene guidance. Among the 35 ill persons, 30 (86%) reported symptom onset on July 1, the day after the event (Figure). Median interval between eating and symptom onset was 20.5 hours (range = 1–45.5 hours). Overall, 33 (94%) ill persons experienced diarrhea, including 27 (77%), 19 (54%), and two (6%) who reported diarrhea that was watery, mucoid, or bloody, respectively. Thirty-two (91%) ill persons reported fever.

Participants reported eating chicken curry, vegetable curry, rice, lentil soup, fried bread, cold and hot salads, and cake; no imported foods were reported. No single food item was statistically significantly associated with illness; however, 37 persons reported eating chicken curry, and those who did had a 47% higher risk for illness than those who did not (risk ratio = 1.47; 95% confidence interval = 0.76–2.83). No food was available for testing…..”