Molecular Epidemiology of Human Metapneumovirus Infection among Children with Severe Acute Respiratory Infection in Huzhou from 2016 to 2020

Abstract

\n Background: Human metapneumovirus (hMPV) is one of the important pathogens of infant respiratory tract infection. However, the molecular epidemiological information relating to hMPV among children hospitalized patients with severe acute respiratory infection (SARI) have not been thoroughly studied as yet. To investigate the infection status and genotypes of hMPV among children hospitalized patients with SARI from January 2016 to December 2020 in Huzhou, China. Methods: A nasopharyngeal flocked swab, nasal wash or combination of nasopharyngeal swab and oropharyngeal swab samples were collected from children with SARI in Huzhou from January 2016 to December 2020. RT-PCR was used to detect the nucleic acid of hMPV. F gene was amplified and sequenced for the positive nucleic acid samples of hMPV. The obtained gene sequences were analyzed by MEGA software (version 7.0). Epidemiological data were analyzed using Microsoft Excel 2010 and service solutions (SPSS) 21.0 software.Results: A total of 1133 children with SARI were collected from 2016 to 2020. Among them, 56 cases were positive for hMPV nucleic acid, with a positive rate of 4.94%. Children under 5 years old accounted for 85.71% of the total positive cases. Higher activity of hMPV infection could be seen in the period in Spring and Winter. and the main epidemic months were December and January-March. The F gene sequences of 28 strains of hMPV were obtained by co-sequencing. Phylogenetic analysis showed that there were A1, B1 and B2 genotypes of hMPV prevalent in Huzhou, and the dominant genotype of hMPV during our study period varied according to surveillance year.Conclusions: HMPV is one of the important pathogens causing acute respiratory virus infection in children in Huzhou, with high incidence in winter and spring seasons and children under the age of 5，A1, B1 and B2 are three prevalent genotypes.