Estimation of Needed Isolation Capacity for an Airborne Influenza Pandemic Shobha S. Subhash, Gio Baracco, Shelly L. Miller, Aaron Eagan, and Lewis J. Radonovich We estimated the number of isolation beds needed to care for a surge in patients during an airborne-transmissible influenza pandemic. Based on US health system data, the amount of available airborne isolation beds needed for ill patients will be exceeded early in the course of a moderate or severe influenza pandemic, requiring medical facilities to find ways to further expand isolation bed capacity. Rather than building large numbers of permanent airborne infection isolation rooms to increase surge capacity, an investment that would come at great financial cost, it may be more prudent to prepare for wide-scale creation of just-in-time temporary negative-pressure wards. A n influenza pandemic that can spread from per- son to person by airborne transmission poses unique containment challenges. Engineering infection control measures—namely, facility airflow management—will play a key role in where ill patients are hospitalized. While North American hospitals have substantial experience re- sponding to outbreaks of seasonal influenza, which is be- lieved to be spread primarily via droplet transmission, few have experience caring for large numbers of patients with infections that are primarily airborne transmissible. The most recent germane example may be the outbreak of severe acute respiratory syndrome (SARS) in 2003, in which Canadian healthcare facilities rapidly built airborne isola- tion units that allowed them to safely care for a large number of SARS patients. 1 The rapid build-up of airborne isolation capacity was a key component in the successful containment of this outbreak, which up to that point had been transmitted mostly in healthcare facilities. 2,3 Public health agencies, professional societies, and infection control experts emphasize the importance of stringent hospi- tal infection prevention measures to help prevent airborne transmission, 4,5 including the capacity to isolate patients in spaces with directional airflow; yet healthcare facilities are sometimes inadvertent nodes of transmission. 6,7 While air- borne infection isolation rooms (AIIR) are widely used in US hospitals for patients with suspected or confirmed airborne- transmissible diseases, the numbers or locations of these rooms are generally not regulated. The US Centers for Disease Control and Prevention (CDC) recommends that each hos- pital or health system perform a risk assessment to make de- cisions about availability of airborne isolation space, based in part on the community-level burden of tuberculosis. 8 Given the low incidence of tuberculosis in the United States, the number of airborne infection isolation beds is generally low. According to a 2003 congressional report, around 66% of urban US hospitals have fewer than 5 isolation beds per Shobha S. Subhash, MPH, is Public Health Program Specialist; Aaron Eagan, MPH, is Associate Director; and Lewis J. Radonovich, MD, is Director; all at the VA National Center for Occupational Health and Infection Control, US Department of Veterans Affairs, Gainesville, Florida. Gio Baracco, MD, is a Physician, Infectious Disease, Hospital Epidemiologist, and Medical Director of the Infection Control Program, Miami VA Healthcare System, Miami, Florida, and Associate Professor of Clinical Medicine, Division of Infectious Diseases, University of Miami Miller School of Medicine, Miami, Florida. Shelly L. Miller, PhD, is Professor of Mechanical Engineering, University of Colorado, Boulder, Colorado. The findings and conclusions in this manuscript are the authors’ own and do not necessarily represent the views of the US Department of Veterans Affairs, the University of Miami, the University of Colorado, or other affiliates. Health Security Volume 14, Number 4, 2016 ª Mary Ann Liebert, Inc. DOI: 10.1089/hs.2016.0015 258