Patients

This was a cross-sectional study performed at Hospital de Clínicas/Universidade Federal do Paraná (HC/UFPR), a 640-bed tertiary care academic center, in Curitiba, Southern Brazil. Hospital databases (Hospital Epidemiology Division and Laboratory of Virology) and/or medical charts of patients hospitalized for acute respiratory infection during the years 2012 and 2013 were reviewed.

Inclusion criteria were defined as either hospitalization due to SARI, identified by active surveillance of the Hospital Epidemiology Division, or investigation for other RVs (despite presence of SARI). SARI was defined as the presence of ILI and signs of respiratory insufficiency (dyspnea, oxygen saturation <95%, or respiratory distress). Data were collected by completion of a form with relevant epidemiological, clinical, and laboratory questions. The Institutional Review Board of HC-UFPR approved the study (Approval number # 18714013.4.0000.0096).