Outbreak Investigation of Food Poisoning at a Primary School, Thung Saliam District, Sukhothai Province.

Abstract

On February 24, 2025, the Situation Awareness Team (SAT) of the Sukhothai Provincial Public Health Office was notified by Thung Saliam Hospital staff regarding a suspected food poisoning outbreak at a primary school in Thung Saliam Subdistrict, Thung Saliam District, Sukhothai Province. An epidemiological investigation was conducted to identify additional cases of food poisoning and confirm the outbreak within the school.The risk factors associated with this outbreak included contaminated food and food sanitation practices of the school kitchen staff. Preventive measures and foodborne disease surveillance guidelines were implemented within the school, with a strong emphasis on food sanitation.The case definition for identifying additional cases included students at the primary school in Thung Saliam Subdistrict, Thung Saliam District, Sukhothai Province, who consumed food and beverages at the school between February 20–21, 2025, and exhibited at least two of the following symptoms: nausea, vomiting, abdominal pain, diarrhea, loose stools, mucus-containing stools, bloody stools, and fever. The investigation identified 166 cases meeting the case definition (Attack rate = 21.53%). Statistical analysis suggested that all food items consumed might have contributed to the outbreak; however, the most significant risk factors associated with illness were:Eating oily rice (OR = 8.71, 95% CI = 5.10–15.00) Boiled chicken (OR = 7.25, 95% CI = 4.28–14.28) Chicken dipping sauce (OR = 4.55, 95% CI = 3.17–6.53).These food items showed a statistically significant association with illness (p < 0.05).The outbreak was classified as a common-source outbreak. The majority of affected individuals experienced abdominal pain, nausea, and vomiting, with a short incubation period of 1–7 hours. The predominant symptoms included vomiting, nausea, abdominal pain, and diarrhea. Based on the investigation findings, health education sessions were provided to students, along with guidelines on proper food storage, hygienic food preparation, and surveillance measures for collecting food samples for laboratory testing in collaboration with the school health officer.