Human metapneumovirus infection in children with influenza-like illness in Hangzhou

Abstract

Objective To investigate the epidemiological characters of human metapneumovirus (hMPV) infection in children with influenza-like illness (ILI). Methods A total of 1 164 throat swabs were collected from children with ILI symptoms in Children's Hospital, Zhejiang University School of Medicine from January 2011 to December 2012. hMPV was detected by using nucleic acid assay, the fusion (F) protein gene of hMPV was amplified by RT-PCR, gene sequencing was performed and the sequences were compared with those in GenBank. Positive rates of hMPV in different age groups were compared with Chi-square test. Results Among 1 164 samples, hMPV was positive in 73 (6.27%) samples. hMPV infection was the most popular in>2-4 y age group (33/220, 15.0%), and the positive rates of hMPV in different age groups were of statistical significance (χ2=40.69, P<0.05). hMPV infection occurred throughout the year, but it was most common in winter and spring. The highest incidence of hMPV infection was observed in December 2012 (12/51, 25.53%). Among 24 samples of hMPV, 14 were with genotype B1, 2 were with genotype B2, and 8 were with genotype A2. The most common genotype was B1 in 2011 (10/12), and A2 in 2012 (8/12). Homology between nucleotide sequences of the 24 samples of hMPV were 81.6% to 100.0%. Conclusions hMPV infection exists in children with ILI in Hangzhou, and the epidemic seasons are winter and spring. hMPV infection is more likely to be found in children aged 2 to 4 years old, and different genotypes may predominated alternately. Key words: Human metapneumovirus; Influenza-like illness; Epidemiologic studies