Human metapneumovirus and respiratory syncytial virus detection in young children with acute bronchiolitis.

This study was conducted to detect human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) in young children hospitalized with acute bronchiolitis, using reverse transcriptase polymerase chain reaction (RT-PCR). Nasopharyngeal secretions were collected from 170 children between 1 and 24 months of age admitted to two tertiary hospitals in northeastern Thailand, between 2002 and 2004. Acute bronchiolitis was defined as the first episode of wheezing associated with tachypnea, increased respiratory effort and an upper respiratory tract infection. Two-thirds (115/170) were positive for viral etiologies: 64.7% RSV (110/170) and 3.5% hMPV (6/170). One patient had a dual infection. hMPV was detected between August and November, while RSV was prevalent from July through March. The clinical manifestations among the 6 hMPV, RSV and non-RSV-infected children were similar. RSV was the leading cause of acute bronchiolitis in young children and hMPV had a low prevalence in northeastern Thailand.