Staphylococcal Food Poisoning Outbreak from a Community Gathering, Wang Nuea District, Lampang Province, Northern Thailand, July 2022

Abstract

On 17 Jul 2022, the Thailand Department of Disease Control was notified about a food poisoning cluster related to a local funeral. We investigated to identify epidemiological characteristics of the outbreak, determine sources, and provide recommendations. A descriptive study and a retrospective cohort analysis were performed. Suspected cases were funeral participants or their household members who had at least one of the following: nausea, vomiting, abdominal pain, diarrhea, or bloody mucous stool during 17–20 Jul 2022. We used multiple logistic regression and transformed the adjusted odds ratio (AOR) to the adjusted risk ratio (ARR). We interviewed chefs and inspected the kitchen. Clinical specimens and food samples were sent for bacteria culture. Three hundred eighteen cases were identified. Ten patients (3.1%) had a shock; three had a septic shock; none died. The median age was 58 (range 47–66). The pork in the lunch boxes (ARR 7.80, 95% CI 0.75–81.34) was the most likely source. Improper food storage and cross-contamination risk were recognized. This outbreak was due to S. aureus with enterotoxin genes A and C, which were isolated from patients, food, and food handlers. Safety standards should be monitored, particularly in large community gatherings where the elderly attend.

Keywords: food poisoning, outbreak investigation, Staphylococcus aureus, community-gathering, food-handlers