CONCISE COMMUNICATION Characterization of Human Metapneumoviruses Isolated from Patients in North America

metapneumovirus (HMPV) was recently identified in The Netherlands and was linked to acute respiratory tract illness. In this study, 11 isolates from 10 patients with respiratory dis-ease from Quebec, Canada, were tested by a reverse-transcriptase polymerase chain reaction based on the fusion protein gene. Identified sequences were consistent with HMPV. The patients were 2 months to 87 years of age (median age, 58 years) and presented with acute respiratory tract illness during the winter season. Sequence studies of the nucleocapsid, fusion, and polymer-ase genes identified 2 main lineages of HMPV and cocirculation of both lineages during the same year. These findings support a previous finding that HMPV is a human respiratory pathogen that merits further study. A new paramyxovirus associated with respiratory illness, human metapneumovirus (HMPV), was described recently [1]. Data from that report suggest that HMPV is similar to respiratory syncytial virus (RSV), in that infection usually occurs during winter months and is common during childhood (most children have serologic evidence of infection by age 5 years). The genomic organization of HMPV resembles that of the avian pneumovirus [2] and has been tentatively assigned to the subfamily Pneumovirinae, genus Metapneumovirus. In the present article, we describe polymerase chain reaction (PCR) and sequencing studies done on 11 isolates from respiratory specimens from 10 Canadian patients with acute respiratory tract illness