An Epidemiological Investigation of a Food Poisoning Outbreak at an Elementary School in Penghu County

D. D. Jiang ； C. L. Wu ； J. P. Hsiu ； K. T. Chen ； M. H. Chen ； J. C. Yang ； G. R. Wang

《Epidemiology Bulletin》 16卷2期 (2000/02) Pp. 19-29

https://doi.org/10.6525/TEB.200002_16(2).0001

並列摘要

The purpose of this epidemiological investigation was to identify the causes of the food poisoning outbreak, the likely responsible food items and the pathogenic agents. A semi-structured questionnaire with the case-control method was used to interview 176 students of an elementary school in Huhsi Township of Penghu County. Among them, 171 (97.2%) students ate the boxed lunch ordered for the school’s track and field sports. Of the 171 students, 109 (48 males and 61 females) met the case definition of food poisoning and showed an attack rate of 63.7%. Their symptoms included abdominal pain (79.8%), vomiting (78.0%), dizziness (71.6%), diarrher (46.8%), headache (45.0%), weakness32.1%), nausea (25.7%), fever (23.9%), and chills (8.3%). The median incubation period was 33 hours and the range was from 6 to 54 hours.
By analyzing the association of the three food items (hamburger, fried chicken quartaer, and coke) in the boxed lunch, with the food poisoning incident, the coke was found to have the highest odds ratio of 9.08, with a 95% confidence limit of 1.71-64.165. The odds ratio of the fried chicken quarter was 1.51, with a 95% confidence limit of 0.53-4.29. That of the hamburger was 0.50, with a 95% confidence limit of 0.18-1.36. Although the coke was found statistically to be significantly associated with the food poisoning, there were no laboratory findings to confirm the relationship.
Due to the fact that the incubation period was relatively long, the major symptoms appeared, and ampicillin proved to have satisfactory result in treating the hospitalized students, it was suspected that enterotoxigenic strains of Escherichia coli (ETEC) was the likely pathogenic agent. The agent could have originated from the ETEC contaminated ice cubes placed in the coke.