Epidemiological Investigation of Food Poisoning in a Mass Gathering

Mass gatherings, frequently organized during festivals, put a strain on the local administration and are always a threat for an outbreak of diseases (communicable/foodborne/waterborne). This study was done to assess approaches to an outbreak of food poisoning which occurred during a mass gathering. This is a cross-sectional study in which interview-based data of items consumed during the feast and symptoms suffered by the participants were collected. Attack rates were calculated, and significance of association was ascertained between food items consumed and development of symptoms. Inspection of the cooking area was done keeping in mind the possible sources of contamination. 277 persons were interviewed, and 180 individuals were identified as cases. The mean age in years was 23.6 (standard deviation 14.1). There were 163 (58.8%) females and 114 (41.2%) males. Epidemic curve showed a classic pattern of point source outbreak. Patients had vomiting (79.44%), pain abdomen (97.22%), and diarrhea (93.33%) with pain abdomen being the most common symptom. The odds ratio calculated was significant for Aloo Chhole 2.70 (confidence interval [CI] 1.28-5.71), Urad Dal 2.80 (CI 1.42-5.50), and Chane ka Choliya 2.08 (CI 1.22-3.53). A good approach toward outbreak investigation can lead to finding out the factors leading to the outbreak. The factors responsible can be prevented in future similar events preventing morbidity and sometimes mortality. An epidemiological approach to an outbreak of food poisoning in a mass gathering is discussed.