An Epidemiological Investigation of a Food Poisoning Outbreak in a Senior High School in Yunlin County
2003 Vol.19 NO.4
An epidemiological investigation into a food poisoning outbreak on 25 September 2002 in a senior high school in Yunlin County was conducted to understand the pathogenic agents and food items associated with the incident. By analyzing 522 copies of the questionnaire collected from students, it was found that 135 students met the definition of case (70 males and 65 females), giving an attack rate of 54.7%. Attack rates by class ranged from 26.3% to 70.0%. Symptoms were abdominal pain (84.4%), diarrhea (80.0%), nausea (39.3%), dizziness (34.1%), vomiting (32.6%), weakness (31.9%), chill (28.9%), and fever (28.1%). The epidemiological curve showed that the incubation periods ranged from 5 hours to 47 hours, with a median of 18 hours. Of the ten rectal swabs, Vibrio parahaemolyticus type K6 was isolated in eight. By their symptoms, incubation periods and findings of laboratory testing, it was decided that the pathogenic agent of the present incident was Vibrio parahaemolyticus.