Masafumi Seki and Yuko Yabuki
We regularly experienced influenza outbreaks in a tertiary-care university hospital in Japan from 2011 to 2014. Prophylactic anti-influenza agents were arbitrarily administered in each ward during each hospital-acquired influenza outbreak until 2014, although routine vaccination programs were implemented for both patients and hospital personnel. After 2015, use of prophylactic anti-influenza agents was controlled by infectious diseases (ID) physicians, and both the number of outbreaks and costs of prophylactic drugs were subsequently reduced. Starting in 2016, laninamivir use increased while oseltamivir use decreased, especially in hospital personnel. Prophylactic use of anti-influenza agents in patients was effective and should be systematically managed by ID specialists.