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.