Food Poisoning Outbreak Investigation in Participants of Volunteer Defense Corps Members Training, Doi Toa District, Chiang Mai Province

Abstract

On 26 May 2022, the Situation Awareness Team of Chiangmai Provincial Public Health Office received a report from Doi Toa hospital an evidence of a food poisoning outbreak suffered many people. All were the participants of Volunteer Defense Corps members training in Doi Toa district, Chiang Mai on 25 May 2022. The investigation started and confirmed the diagnosis, which was to initiate to describe the outbreak pattern, to determine sources of contamination and to propose suitable prevention and control measures of this outbreak. The assessment conducted a retrospective cohort to identify risk factors of 93 subjects in this event. through an interview form, medical records reviewing, laboratory check-lists and environmental survey. The outbreak was described by frequency, percentage, median, minimum and maximum values and data analyses. The study found 64 confirmed cases and an attack rate was 68.82 percentages. The main clinical symptoms from the patients were diarrhea, stomach cramp and nausea. The incubation period was average 16 hours. This training was a camp training that participants would have the same food in a meal-box every meal, so we could not find the relationship of the variables. Therefore, the expected cause was summarized from data analyses that assumed the chicken rice and its sauce consumed on 25^th May 2022 in a lunch meal-box. Laboratory's findings found Bacillus cereus in its sauce. The environmental survey showed that the cooking place was taken on the ground, the sauce set aside for a long time after cooking and became spoiled. We suggested them for hygienic sanitary and guidelines for investigating the disease in case of eating a similar food up every meal.