According to data presented at the CDC’s Annual Epidemic Intelligence Service Conference, contaminated asparagus was the likely source of a Shigella outbreak at a Yarnhill County wedding in Oregon in 2018. One hundred twelve people were sickened; 10 people were hospitalized.
The Oregon Health Authority first received reports of gastroenteritis at a wedding in august 2018. Shigella flexneri type 3a was identified in stool samples taken from patients. That particular pathogen accounts for less than 3% of the Shigella flexneri isolates in the United States.
Researchers asked the wedding attendees to fill out surveys to try to find the cause of the outbreak. Presumptive cases were people who had diarrhea lasting 5 days or less. Confirmed cases were patents who had Shigella flexneri isolated from stool. The caterer was inspected by the Multnomah Count yHealth Department. The wedding venue was inspected by the Oregon Department of Agriculture.
A total of 263 people attended the wedding. Seventy-five percent of those people responded to the survey. The patient age range was from 2 to 93 years. Of the 95 people who responded, 97% said they got sick within 12 to 72 hours after the wedding. Fifty-seven patients went to a health care facility.
Investigators found that only asparagus was associated with illness. Steven I. Rekant, an EIS Office with the Oregon Public Health Authority, said, “This was one of the largest foodborne outbreaks of shigellosis in U.S. history. It was the second largest ever attributed to Shigella flexneri and that type of Shigella flexneri, type 3a, is uncommon in Oregon. Ninety-six percent of people who became ill ate asparagus, which was the highest rate among all foods. Asparagus consumption also had the biggest difference between ill people who ate it and well people, at 31%.”
The epidemic curve also indicated a point source that implicated asparagus. In addition, “poor hygiene on the part of the food-handler [was] the ‘likely cause of contamination.'”
