RESUMEN
Every summer the U.S. Army Reserve Officer Training Corps (ROTC) conducts the Leader Development Assessment Course (LDAC) for several thousand upcoming senior-year cadets. This study describes respiratory illnesses at 2009 ROTC LDAC after the emergence of the novel H1N1 influenza pandemic. This retrospective cohort study examines 5554 cadets and 1,616 cadres from 2009, and 5180 LDAC 2008 cadets. Respiratory clinic visits for 2009 cadets were higher than 2009 cadres and 2008 cadets, at 8.7, 2.0, and 4.2 visits per 1000 person-days available, respectively (p < 0.001). Further, respiratory illness hospitalizations and isolations were higher for 2009 cadets than cadres (p = 0.020). Although substantial efforts were made to prevent respiratory infections, there was considerable impact from respiratory illnesses, in the context of the novel H1N1 influenza pandemic, among 2009 ROTC LDAC participants. Our experience offers important lessons for future LDAC planning and for similar close quarters living circumstances.