Airborne Transmission via HVAC of Acute Respiratory Infections in Military Facilities? Review of a Basic Training Cohort Study

There is great interest in preventing the spread of acute respiratory infections (ARI) in military housing and in other facilities with multiple occupants such as hospitals. There has been some research on the mode of transmission of ARIs in these types of occupancies, with several studies focusing on direct and indirect contact. This study, based on several barracks at the largest basic training facility for the Army in the United States, investigates the role of airborne transmission via heating, ventilating and air conditioning (HVAC) systems as compared to a combination of airborne, indirect contact and direct contact transmission in a room. The results indicate that there is a significant increase in the number of cases which might be attributable to airborne transmission via HVAC systems in several situations, both for ARIs that required hospitalization, and those which did not.