Detection of human metapneumovirus in infants with acute respiratory tract infection.

Both respiratory syncytial virus (RSV) and human metapneumovirus (hMPV), a recently discovered respiratory pathogen classified in the Paramyxoviridae family, have been associated with acute respiratory tract infections (ARTI) in infants. The aim of our study was to determine the incidence and clinical features of hMPV infection in infants presenting with ARTI at a tertiary children's hospital in Greece during the 2007-2008 and 2008-2009 winter seasons. Routine nasal swabs were obtained from 127 infants younger than 12 months of age. The specimens were tested for the presence of hMPV and RSV antigens using validated enzyme-linked immunoassays. The mean age of the studied infants was 3 months (range 19 days to 12 months). hMPV was detected in 8 (6.3%) children, 4 boys and 4 girls, while RSV was detected in 39 (30.7%) children, 22 boys and 17 girls. In 7 children, hMPV was identified as a unique viral pathogen, while only 1 child was co-infected with hMPV and RSV. Bronchiolitis was diagnosed in all hMPV-positive cases, while only two cases required hospitalization and supplemental oxygen therapy. Our results provide further evidence of the importance of hMPV as a pathogen associated with community-acquired ARTI in infants in Greece.