An Outbreak of Gastroenteritis among students of a religious boarding school, district Islamabad: A Retrospective Cohort Study

Background: On 1 March, 2018, 15 students of a religious boarding school presented to a tertiary care hospital in Islamabad with complaints of nausea, vomiting, abdominal pain and diarrhea. A team of FELTP fellows were tasked to investigate the suspected outbreak to confirm diagnosis, determine magnitude, evaluate possible risk factors, identify the source and implement control measures. Methods: A retrospective cohort study was conducted from 25 February to 5 March, 2018. Medical records were reviewed at the hospital. All the students and staff of the boarding school were interviewed using a structured questionnaire. A case was defined as any student of the religious school reported with nausea, abdominal discomfort and one of the following symptoms of vomiting, diarrhea, and chills on 1 March, 2018. Information on demographics, history of food intake and clinical features was collected. Suspected food items and drinking water samples were sent to the National Institute of Health for microbiological analysis. Frequencies and attack rates were calculated and risk ratios computed at 95% confidence interval at the margin of error P