Genetic evolution of influenza B virus hemagglutinin (HA) and neuraminidase (NA) genes in Hangzhou between 2014 and 2019
10.3760/cma.j.cn112309-20200312-00114
- VernacularTitle:杭州地区2014—2019年乙型流感病毒HA和NA基因遗传进化分析
- Author:
Xin QIAN
1
;
Xinfen YU
;
Jun LI
;
Yinyan ZHOU
;
Yanping WEN
Author Information
1. 杭州市疾病预防控制中心卫生检验中心 310021
- From:
Chinese Journal of Microbiology and Immunology
2020;40(7):523-529
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the prevalence of influenza B virus in Hangzhou between 2014 and 2019, and the variation in hemagglutinin (HA) and neuraminidase (NA) genes.Methods:Viruses were isolated from throat swabs collected from 10 481 patients with influenza-like illness in Hangzhou from October 2014 to September 2019. The subtypes of influenza viruses were identified by real-time RT-PCR. HA and NA genes of some influenza B virus strains were amplified with specific primers and then analyzed with gene sequencing and phylogenetic analysis.Results:Influenza B virus had circulated in Hangzhou every year since 2014 and caused a much higher morbidity in people aged 5-14 years. The Victoria lineage of influenza B virus circulating in Hangzhou between 2014 and 2019 belonged to the V1A clade, while the Yamagata lineage belonged to the Y3 clade. Homology analysis showed that 124 strains shared 94.67%-100.00% homology in HA gene sequences and 128 strains shared 97.13%-100.00% homology in NA gene sequences. Influenza B virus possessed several mutations in the antigenic sites of HA and NA.Conclusions:Influenza B virus played a critical role in the influenza epidemics in Hangzhou. During 2014 to 2019, genetic mutations in the antigenic sites of HA and NA and reassortant strains were detected, and there was a mismatch between epidemic and vaccine strains. However, no drug-resistant virus was found.
