Data needed to guide influenza vaccine policies are lacking in tropical countries. We multiplied the number of severe acute respiratory infections by the proportion testing positive for influenza. There were ≈6,699 influenza hospitalizations and 803 deaths in Costa Rica during 2009-2012, supporting continuation of a national influenza vaccine program.
Keywords: Americas; Costa Rica; hospitalization rate; influenza; mortality rate; severe acute respiratory infections; tropical; viruses.