An Outbreak of Gastroenteritis Among Iranian Pilgrims of Hajj during 2011

Background: Hajj is the largest annual mass gathering of muslims. The exorbitant crowd of pilgrims and the poor condition of personal hygiene and nutrition are the main predisposing factors for different infections and food poisonings. Objectives: This study investigates a gastroenteritis outbreak among an Iranian caravan of hajj pilgrims. Materials and Methods: Studying the outbreak was carried out through a cohort study and it investigated the attack rates of the two groups of pilgrims who had consumed or had not consumed various food products. The relative risk and 95% confidence interval of each food product was then calculated. Results: Only canned rice and fish had a relative risk higher than one, although both were not statistically significant. Therefore, it could be stated that the consumed foodstuffs have not caused this outbreak. Conclusions: None of the foodstuffs distributed among the pilgrims were the reason for this disease, and studying outbreaks in caravans with higher sample sizes is suggested.