Prevalence and clinical and molecular characterization of human metapneumovirus in children with acute respiratory infection in China.
BACKGROUND
Human metapneumovirus (HMPV), a newly discovered paramyxovirus, has been associated with acute respiratory tract infections (ARTIs). However, the prevalence and molecular characteristics of HMPV in China are still unclear.


METHODS
A total of 661 nasopharyngeal aspirates (NPA) specimens were collected from 661 children with ARTIs between December 2006 and November 2008. Specimens were screened for HMPV by reverse transcription-polymerase reaction. All positive amplification products were confirmed by sequencing.


RESULTS
HMPV was detected in 45 patients (6.80%) of the 661 children. The HMPV-infected patients were from 29 days to 9 years of age. A high incidence of HMPV infection (84.4%) was observed during the winter-spring season. Of the 45 HMPV-positive patients, 25 (55.6%) were co-infected with other respiratory viruses, and respiratory syncytial virus (RSV) was the most common additional respiratory virus. The most common clinical diagnosis was bronchopneumonia (57.8%) and cough (88.9%) was the most common clinical symptom. Phylogenetic analysis of the F gene revealed that 80% of the HMPV detected were A2, 2.2% were A1, and 17.8% were B1. Statistical analyses showed that sex, ages, seasons, and severity of the disease did not correlate with HMPV genotype (P = 0.986, 0.347, 0.660, 0.252), but viral coinfection with HMPV increased hospitalization rates (P = 0.005).


CONCLUSIONS
HMPV was frequently detected in the pediatric patients with ARTI in China. RSV was the most common coinfection virus and coinfection increased hospitalization rates. All HMPV subgroups except B2 cocirculated and there was no association found between HMPV genotypes and severity of disease.
Xiao
Ni-guang
NG
Department of Pediatrics, The People's Hospital, Hunan Province, China.
Xie
Zhi-ping
ZP
Zhang
Bing
B
Yuan
Xin-hui
XH
Song
Jing-rong
JR
Gao
Han-chun
HC
Zhang
Rong-fang
RF
Hou
Yun-de
YD
Duan
Zhao-jun
ZJ
D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D015897:Comorbidity; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D029121:Metapneumovirus / Q000145:classification* / Q000302:isolation & purification; D017720:Molecular Epidemiology; D009305:Nasopharynx / Q000821:virology; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000473:pathology* / Q000821:virology; D010802:Phylogeny; D015995:Prevalence; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000473:pathology* / Q000821:virology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012621:Seasons; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins