Children with respiratory disease associated with metapneumovirus in Hong Kong

Abstract

Human metapneumovirus (HMPV) is a newly discovered pathogen thought to be associated with respiratory disease. We report the results of a study of 587 children hospitalized with respiratory infection over a 13-month period. HMPV was detected in the nasopharyngeal aspirates from 32 (5.5%) children by reverse transcription-polymerase chain reaction. HMPV infection was associated with clinical diagnoses of pneumonia (36%), asthma exacerbation (23%), or acute bronchiolitis (10%). When compared to those with respiratory syncytial virus infection, children with HMPV infection were older, and wheezing was more likely to represent asthma exacerbation rather than acute bronchiolitis. HMPV viral activity peaked during the spring-summer period in Hong Kong. Phylogenetically, all HMPV virus strains from Hong Kong belonged to one of the two genetic lineages previously described. HMPV contributed to 441.6 hospital admissions per 100,000 population <6 years of age.

Figure 1

Number of patients tested and percentage positive for human metapneumovirus and the seasonality of other common respiratory viruses during the study period. Data for human metapneumovirus are based on a subset of patients admitted to Queen Mary Hospital (see Methods); data for the other respiratory viruses are based on all children admitted.

Figure 2

Phylogenetic tree of the human metapneumovirus a) L gene and b) F gene. Viruses detected in Hong Kong are prefixed HK, and the sequences have been deposited in GenBank under accession numbers AY294849 through to AY294870. Other viral sequences were obtained from GenBank. Abbreviations used: APV, avian pneumovirus; NL, the Netherlands.