Investigation of a Vibrio parahaemolyticus Poisoning at an Elementary School in Yuanli Township, Miaoli County

W. C. Huang ； D. D. Jiang ； S. L. Chuang ； K. T. Chen ； C. B. Horng

《Epidemiology Bulletin》 14卷10期 (1998/10) Pp. 169-179

https://doi.org/10.6525/TEB.199810_14(10).0001

並列摘要

At 10 PM of 11 December 1997, 77 of the 144 students of the Yuanli elementary school in Yuanli township, Miaoli county, started to develop symptoms such as: watery diarrhea (42.4%), abdominal pain (42.4%), vomiting (35.4%), headache/dizziness (22.2%), chilliness (16.7%), nausea (12.5%), and fever (6.3%). About 50 of them visited the Lee’s and Chiu’s General Hospital of the township for treatment. Of them, 11 were hospitalized for care. All these students ate the lunch ordered by the school. The purpose of the investigation was to find out the causes and pathogenic agents of the poisoning.
The investigators applied a questionnaire to collect the following information: the demographic characteristics of the cases, food items eaten on 11 December, symptoms and signs, time of onset, medical care, and duration taken recovery. By analyzing previously collected information, the results indicated that the incubation period ranged from 2-40 hours, with a median and a mode of 15 hours respectively; and the cases took approximately three days to recover. These epidemiological findings and the clinical symptoms led to the conclusion of food poisoning possibility induced by Virbio parahaemolyticus. In addition, the National Institute of Preventive Medicine had isolated 13 cases of Vibrio parahaemolyticus type K6 from 15 rectal swabs. Vibrio parahaemolyticus was also isolated from specimens collected from the hospitalized students by the Lee’s General Hospital laboratory and from the residue specimens of the fried pork chop by the National Laboratories of Foods and Drugs. It was therefore concluded that the pathogenic agent for the food poisoning was Vibrio parahaemolyticus.
Statistical analysis showed that the fried prok chop was significantly related to the incident (p＜0.01) with a relative risk of 2.08 (95% confidence interval, 1.34~3.23). Since Vibrio parahaemolyticus was isolated from the residue specimen of the fried pork chop, it was considered as the food item responsible for the poisoning.