Epidemiological analysis of influenza A (H1N1)pdm09 in Hebei province from 2017 to 2020
10.3760/cma.j.cn112866-20210330-00055
- VernacularTitle:2017—2020年河北省甲型H1N1流感流行特征分析
- Author:
Guangyue HAN
1
;
Yan LI
;
Caixiao JIANG
;
Yuyan YANG
;
Yanfang LIU
;
Lanfen LIU
;
Shunxiang QI
Author Information
1. 河北省疾病预防控制中心，石家庄 050021
- Keywords:
Influenza A(H1N1)pdm09;
Epidemiological characteristics;
Hemagglutinin gene;
Evolutionary analysis
- From:
Chinese Journal of Experimental and Clinical Virology
2021;35(3):272-275
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To understand the epidemic characteristics of influenza A (H1N1)pdm09 and hemagglutinin (HA) gene mutations in Hebei province from 2017 to 2020, in order to provide scientific basis for the prevention and control of influenza.Methods:The analysis was conducted on the data of Hebei province, which was down loaded from the Chinese National Influenza Surveillance Network from April 2017 to March 2020, and 37 influenza A (H1N1)pdm09 strains were selected for sequencing and evolutionary analysis of HA gene.Results:A total of 57 670 throat swabs from influenza like illness (ILI) patients in Hebei province were detected, and 8 569 samples were positive for the viral nucleic acid, with the positive rate of 14.86%, influenza A (H1N1)pdm09 accounted for 40.52% (3 472/8 569). The cases were detected throughout the whole 11 regions of Hebei province. All age groups were infected by influenza A (H1N1) virus, and the highest detection rate was in the 25- year age group, the peak detection rate was in winter and spring seasons. The HA genes of 37 strains of influenza A (H1N1) virus belong to 6B.1 branch, and the amino acid homology is from 97.31% to 100.00%. S74R, S164T, S183P and I295V were the major amino acid variation sites in 2017-2018 influenza season. S183P, H126Y, N129D, T185I, L233I and N260D were the major amino acid variation sites of epidemic strains in 2018-2019 influenza season. The variation sites of D187A and Q189E of epidemic strains were found in 2019-2020 influenza season.Conclusions:The prevalence of influenza A(H1N1) pdm09 in Hebei province has an obvious seasonality. The HA gene and its encoded amino acid have been mutating gradually. The strains which were isolated recently were clustered with the 2020-2021 season northern hemisphere vaccine strain A/Guangdong-Maonan/SWL1536/2019.
