Outbreak of seafood-related food poisoning from undetectable Vibrio parahaemolyticus-like pathogen, Chiang Mai Province, Thailand, December 2020.

Objective: On 1 December 2020, the Department of Disease Control of Thailand was notified of a cluster of food poisoning cases among participants at a church festival in Mae Ai district, Chiang Mai province. We conducted an outbreak investigation to confirm diagnosis, describe the epidemiological characteristics of the outbreak, identify possible sources of the outbreak and provide appropriate control measures.

Methods: We reviewed medical records of the food poisoning cases from the health care centres.