Outbreak Investigation of Food Poisoning Caused by Ingestion of Hura crepitans Seeds among Primary School Students, Dong Klang Subdistrict, Khon San District, Chaiyaphum Province, Thailand, 22–24 May 2025

Abstract

On May 23, 2025, the Surveillance and Rapid Response Team (SRRT) of Khon San District, Chaiyaphum Province, was notified by Khon San Hospital of a cluster of food poisoning cases among students at a primary school in Dong Klang Subdistrict, Khon San District, Chaiyaphum Province. The event met the criteria for a district-level outbreak investigation. The SRRT conducted a field investigation to confirm the diagnosis, describe the outbreak characteristics, identify causes and risk factors, and implement prevention and control measures. A descriptive epidemiological investigation was conducted using medical record reviews, interviews with patients and relevant contacts, active case finding, and environmental surveys. Data were analyzed using descriptive statistics. The results revealed that a total of 13 cases of food poisoning attributed to the ingestion of Hura crepitans seeds were identified (attack rate of 100%). All cases were students, comprising 7 males and 6 females. The median age was 11 years (range 8–12 years). Symptom onset occurred within 1–4 hours after ingestion. The main symptoms were abdominal pain (100%), sore throat or throat irritation (84.62%), diarrhea (76.92%), abdominal discomfort (53.85%), and vomiting (15.38%). Of the 13 cases identified, 11 patients were admitted to the hospital, while 2 were treated at home. No fatalities were reported. Epidemiological investigation showed that all cases had a history of consuming H. crepitans seeds that had fallen on the school playground. In contrast, no symptoms were reported among students who had not ingested the seeds. Control measures were promptly implemented, including the collection and disposal of H. crepitans seeds from the school premises, restriction of access to the affected area, installation of warning signs for toxic plants, and provision of health education to teachers, students, and parents. All cases were closely monitored, and active surveillance was conducted in the school and community for 2 days. No additional cases were identified.