An outbreak of food poisoning in a military establishment

Background: An outbreak of food poisoning in a military establishment mess was investigated and remedial measures suggested. Methods: A total of 391 persons had consumed meals in the mess on the day of the outbreak. A detailed food history was taken from available persons and the attack rates of each specific food items were calculated with the relative risks. Results: Of the 391 persons who had consumed meals at the mess, 123 were affected giving an overall attack rate of 31.5%. Majority of the cases had loose motions, fever, pain abdomen and vomiting. The maximum attack rate (65.1%) was for those who had eaten chicken preparation. The relative risk was also highest for those who had eaten chicken at lunch on the day of the outbreak (RR — 33.21, 95% CI 8.39 to 131.53). The mean incubation period was 19.73 hours (range 6 – 57 hours). The median incubation period was 18 hours. Bacteriological confirmation was not successful. Conclusion: The chicken dish was the epidemiologically incriminating food item responsible for the outbreak. Clinical and epidemiological features were suggestive of salmonella food poisoning. However, same could not be confirmed bacteriologically.