Foodborne outbreak investigation in elementary school, Gunungkidul District, January 2024: A cohort retrospective study design

¹ Field Epidemiology Training Program, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
² Department of Biostatistics, Epidemiology, and Population Health, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
³ Center for Tropical Medicine, Faculty Medicine, Public Health, and Nursing, Universitas Gadjah Mada, Yogyakarta, Indonesia
⁴ Gunungkidul District Health Office, Yogyakarta, Indonesia

^* Corresponding author: denisoxyhandika@mail.ugm.ac.id

Abstract

On January 25, 2024, the Gunungkidul District Health Office was notified that three elementary school students fell ill after consuming snacks sold near the school. A team from Semanu II Health Center, in collaboration with the Gunungkidul District Health Office and Field Epidemiology Training Program Universitas Gadjah Mada residents, conducted an epidemiological investigation. This investigation aimed to identify the sources, risk factors, assess its extent, and provide suggestions for outbreak management. An active case-finding investigation was conducted, followed by a retrospective cohort study. Cases were individuals with one or more symptoms like nausea, vomiting, stomach pain, dizziness, chills, shortness of breath, and sore throat after consuming snacks sold near the school on January 25, 2024. In-depth interviews with structured questionnaires were used for data collection. Food handlers’ hygiene practices were observed, and food samples were tested at a health laboratory. A statistical analysis using chi-square and log-binomial regression was performed to measure the association in this study. 102 individuals were interviewed, 12 were considered cases. Most cases were in males (66.67%), aged 5 to 11 (66.67%), primarily third-grade students (50%), and a common symptom was nausea (100.00%). The epidemic curve had a common source, with incubation periods varying from 30 minutes to 14 hours. The median incubation period was 1 hour, while the average was 2 hours 23 minutes. The “Egg Macaroni” was associated with higher illness risk in this outbreak (aRR=14.5; 95% CI=1.7 − 21.1). Biological pathogens were detected in lab tests. Factors like poor hygiene practices, improper storage, reheating, and cross-contamination posed risks. The conclusion is that a foodborne outbreak at elementary school occurred in Gunungkidul District on January 25, 2024, and was caused by Bacillus cereus and mold/yeast. Implementation of healthy canteens in the school environment and increased education to improve food safety supervision is recommended.