OUTBREAK OF HUMAN METAPNEUMOVIRUS INFECTION IN CHILDREN IN CHONGQING, CHINA

Abstract

INTRODUCTION: Human metapneumovirus (hMPV) is a newly discovered respiratory pathogen. Understanding of the epidemiology of hMPV infection is limited in China. OBJECTIVE: The objective of this study was to describe an outbreak of hMPV infection in Chongqing, China, and study the high coinfection rates of hMPV and respiratory syncytial virus (RSV). METHODS: A total of 93 nasopharyngeal aspirates (NPAs) were collected from hospitalized children with acute respiratory diseases during December 2006 to January 2007. Total RNA was extracted from NPAs by using QIAmp viral RNA minikit and amplified for hMPV F gene and RSV G gene by real-time reverse-transcription polymerase chain reaction (RT-PCR) and traditional PCR, respectively. Most of the hMPV-positive samples were confirmed by traditional RT-PCR and subsequent nucleotide sequence analysis. RESULTS: Of 93 NPAs, 38 (40.9%) were positive for hMPV and 52 (55.9%) were positive for RSV. Twenty-three (24.7%) revealed coinfection with both viruses. Ages of patients with hMPV infection ranged from 1 month to 31 months; 78.9% were younger than 2 years, and 47.4% were younger than 6 months. Cough was the most common symptom, 78.9% (30 of 38) had wheezing, and 42.1% had fever. CONCLUSIONS: HMPV seems to be an important respiratory pathogen in young children in Chongqing, China. Coinfection of hMPV and RSV may frequently occur during the winter season. Whether coinfection leads to more severe disease remains unknown.