Human metapneumovirus as a cause of community-acquired respiratory illness

Abstract

Human metapneumovirus (HMPV) is a recently identified Paramyxovirus first isolated from hospitalized children with acute respiratory tract infections (ARTI). We sought evidence of HMPV infection in patients who had visited general practitioners, had influenzalike illnesses (ILI), and had negative tests for influenza and Human respiratory syncytial virus (HRSV). As part of national virologic surveillance, sentinel general practices in England and Wales collected samples from patients of all ages with ILI during winter 2000-01. Reverse transcriptase-polymerase chain reaction (PCR) for HMPV, influenza A (H1 and H3), influenza B, and HRSV (A and B) was used to screen combined nose and throat swabs. PCR products from the HMPV-positive samples were sequenced to confirm identity and construct phylogenetic trees. Of 711 swabs submitted, 408 (57.3%) were negative for influenza and HRSV; HMPV was identified in 9 (2.2%) patients. HMPV appears to be associated with community-acquired ARTI. The extent of illness and possible complications related to this new human virus need to be clarified.

Figure 1

Incidence of influenzalike illness consultations in England during winter 2000–01 and timing of collection of positive samples for human Metapneumovirus (HMPV). HRSV, Human respiratory syncytial virus; PCR, polymerase chain reaction; RCGP, Royal College of General Practitioners.

Figure 2

Phylogenetic tree showing sequence analysis of human Metapneumovirus (HMPV). Isolates prefixed with L were obtained from GenBank and represent isolates from the Netherlands. Isolates prefixed with 00hL are from this study; the following number indicates strain designations throughout the season: a, sample from an adult; c, sample from a child (<15 years). Scale shown is proportional to number of nucleotide substitutions per site.