An analysis of the seasonal epidemic characteristics of influenza in Kunming City of Yunnan Province from 2010 to 2024
10.19428/j.cnki.sjpm.2025.250217
- VernacularTitle:2010—2024年云南省昆明市流行性感冒季节性流行特征分析
- Author:
Zexin HU
1
;
Min DAI
2
;
Wenlong LI
2
;
Minghan WANG
1
;
Xiaowei DENG
3
;
Yue DING
1
;
Hongjie YU
1
;
Juan YANG
1
;
Hong LIU
2
Author Information
1. Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
2. Kunming Center for Disease Control and Prevention, Kunming, Yunnan 650228, China
3. School of Public Health, Nanjing Medical University, National Vaccine Innovation Platform, Nanjing, Jiangsu 210008, China
- Publication Type:Journal Article
- Keywords:
influenza;
seasonality;
Kunming City;
prevention and control strategy
- From:
Shanghai Journal of Preventive Medicine
2025;37(8):643-648
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo characterize the seasonal patterns of influenza in Kunming City, Yunnan Province before, during, and after the COVID-19 pandemic, and provide scientific evidence for optimizing influenza prevention and control strategies. MethodsInfluenza-like illness (ILI) and etiological surveillance data for influenza from the 14th week of 2010 to the 13th week of 2024 in Kunming City of Yunnan Province were collected. Harmonic regression models were constructed to analyze the epidemic characteristics and seasonal patterns of influenza before (2010/2011‒2019/2020 influenza seasons), during (2020/2021‒2022/2023 influenza seasons), and after (2023/2024 influenza season) the COVID-19 pandemic. ResultsBefore the COVID-19 pandemic, influenza in Kunming City mainly exhibited an annual cyclic pattern without a significant semi-annual periodicity, peaking from December to February of the next year, with an epidemic duration of 20‒30 weeks. During the pandemic, influenza seasonality shifted, with an increase in semi-annual periodicity and an approximate one month delay in annual peaks. However, after the pandemic, the annual amplitude of influenza increased compared with that before the pandemic, and the epidemic duration extended by about one month. Although the annual peak largely reverted to the pre-pandemic levels, the annual peaks for different influenza subtypes/lineages had not fully recovered. ConclusionInfluenza seasonality in Kunming City underwent substantial alterations following the COVID-19 pandemic and has not yet fully reverted to pre-pandemic levels. Continuous surveillance on different subtypes/lineages of influenza viruses remains essential, and prevention and control strategies should be adjusted and optimized in a timely manner based on current epidemic trends.
