Characteristics of influenza virus epidemic in Yiwu City， Zhejiang Province from 2017 to 2022
10.19428/j.cnki.sjpm.2024.23759
- VernacularTitle:2017—2022年浙江省义乌市流感病毒流行特征分析
- Author:
Buqing CHEN
1
;
Bo CHEN
1
;
Junfang LOU
1
;
Jinhua CHEN
1
Author Information
1. Yiwu Center for Disease Control and Prevention， Yiwu， Zhejiang 322000， China
- Publication Type:Journal Article
- Keywords:
influenza;
influenza-like illness;
virology;
H3N2
- From:
Shanghai Journal of Preventive Medicine
2024;36(7):712-715
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo investigate the epidemiological trends of influenza in Yiwu City， Zhejiang Province from 2017 to 2022， and to provide references for local adjustments to influenza prevention and control strategies. MethodsReal-time fluorescence quantitative PCR was used to detect and type influenza viruses in nasal and pharyngeal swab specimens of the patients with influenza-like illness （ILI）. The results were statistically analyzed. ResultsFrom 2017 to 2022， a total of 106 661 ILI cases were reported in Yiwu City， with annual reported cases of 31 273， 33 522， 20 090， 9 965， 3 202， and 8 609， respectively. The majority of ILI cases were in the age group of ≤14 years， accounting for 89.16%. A total of 6 893 specimens were collected and tested， of which 945 were tested positive for influenza virus nucleic acid， with an overall positivity rate of 13.71%. The dominant subtypes were H3N2 and B⁃Victoria， accounting for 40.63% （384/945） and 35.03% （331/945） respectively. The highest positivity rate was in 2019， at 25.19% （265/1 052）. The positivity rates significantly decreased in 2020 and 2021， to 5.74% （66/1 149） and 5.77% （75/1 300）， respectively. The rate increased in 2022 to 13.85% （180/1 300）. The highest proportion of A/H3N2 positivity was in 2017， at 69.14% （168/243）. The highest proportion of A/H1N1 positivity was in 2018，at 50.86%（59/116）. The highest proportion of B/Victoria positivity was in 2021， at 100.00% （75/75）. The highest proportion of B/Yamagata positivity was in 2018， at 5.17% （6/116）. ConclusionInfluenza in Yiwu City exhibits obvious seasonal patterns， with two peaks in winter-spring and summer. Dominant strains such as A/H3N2， B/Victoria， and A/H1N1 alternate or co-circulate. During the COVID-19 pandemic， seasonal influenza significantly decreased， and a series of prevention and control measures had a positive effect on influenza prevention and control.
