Monitoring respiratory virus infection in the metropolitan area of Belo Horizonte, Brazil, 2011-2013.

OBJECTIVE to analyze the circulation of respiratory viruses in people living in the metropolitan area of Belo Horizonte, Brazil, and hospitalized in Belo Horizonte from 2011 to 2013. METHODS this is a descriptive study of 5,158 patients with Severe Acute Respiratory Syndrome; a comparison was made between the characteristics of confirmed cases and those of discarded cases or cases without swab samples. RESULTS Influenza A virus accounted for half the isolated viruses, especially subtype A(H1N1)pdm09 among patients aged 20-59 years old, and subtype A(H3N2) in those aged 60 or over; the most frequently identified respiratory virus among children under five years old was respiratory syncytial virus (65.6%), followed by influenza A virus (21.2%); influenza virus circulated in all seasons of the year and its periods of greatest incidence were interspersed with those of higher Respiratory Syncytial Virus activity. CONCLUSION monitoring respiratory viruses contributes to knowledge about periods of virus circulation and the adoption of specific control measures.