Acute gastroenteritis outbreak associated to norovirus GI.9 in a Portuguese army base.

Gastroenteritis is considered a major illness within the military settings being caused by foodborne enteric pathogens that are particularly easily spread in the crowded conditions of military camps. Gastroenteritis outbreaks caused by norovirus usually affect a great number of soldiers due to the low infectious dose, copious viral shedding, and environmental stability. The present study describes the investigation of an outbreak of acute gastroenteritis that occurred in April 2015 in a Portuguese army base, focusing on the study of the epidemiological curve, symptoms experienced by the affected soldiers, and results of food, water, and stool microbiological analysis. From a total of 938 military personnel stationed on the base 46 soldiers developed acute gastroenteritis. Stool analysis of seven cases showed to be positive for norovirus GI.9 that was the probable cause of the outbreak. This report shows that genogroup I norovirus can also cause considerable morbidity in healthy young soldiers, affecting the operational effectiveness on the military forces. J. Med. Virol. 89:922-925, 2017. © 2016 Wiley Periodicals, Inc.