Detection of human metapneumovirus RNA sequences in nasopharyngeal aspirates of young French children with acute bronchiolitis by real-time reverse transcriptase PCR and phylogenetic analysis

Abstract

Human metapneumovirus (HMPV) was the unique viral pathogen detected by a real-time reverse transcriptase PCR (RT-PCR) assay in 6 (6.4%) of 94 consecutive French children hospitalized for acute bronchiolitis from September 2001 to June 2002. This virus was identified as the third etiological cause of bronchiolitis, after respiratory syncytial virus and rhinovirus (35 [37%] and 21 [22%] of 94 cases, respectively). Phylogenetic analysis of F-gene sequences demonstrated the cocirculation of distinct HMPV genotypes during this study. These findings highlight the need to implement a rapid HMPV RT-PCR detection assay for the clinical diagnosis of respiratory infections in pediatric patients with bronchiolitis.

FIG. 1.

Monthly distribution of bronchiolitis cases with an acute viral respiratory infection during a 10-month period (from September 2001 to June 2002). RSV, respiratory syncytial virus; IVA, influenza virus A; PIV3, parainfluenza virus 3; HMPV, human metapneumovirus; RV, rhinovirus; EV, enterovirus.

FIG. 2.

Phylogenetic relationships observed in maximum likelihood analysis of the human metapneumovirus fusion nucleotide sequences. Bootstrap proportions were plotted at the main internal branches of the phylogram to show the support values. The scale refers to the distance between sequences. CAN, Canada; NLD, The Netherlands; FR, France. Canadian strains are under GenBank accession numbers AY145242 to AY145301; the Dutch HPMV strain is under GenBank accession number AF371367; the French strains are under GenBank accession numbers AY626963 to AY626969.