Influenza Sentinel Surveillance and Severe Acute Respiratory Infection in a Reference Hospital in Southern Brazil.

Introduction: We report the results of the active surveillance of influenza infections in hospitalized patients and the evaluation of the seasonality and correlation with temperature and rainfall data.

Methods: During the 2-year study period, 775 patients were tested for 15 respiratory viruses (RVs).

Results: Most of the 57% of (n=444) virus-positive samples were human rhinovirus and respiratory syncytial virus. However, 10.4% (n=46) were influenza virus (80% FluA; 20% FluB). Age and SARI were significantly associated with influenza. FluB circulation was higher is 2013.

Conclusions: In the post-epidemic period, influenza remains an important cause of hospitalization in SARI patients.