Influenza virus infection of influenza-like illness at a sentinel hospital in Baoshan District of Shanghai from the monitoring year of 2015 to 2023
10.19428/j.cnki.sjpm.2025.24748
- VernacularTitle:2015—2023监测年上海市宝山区某哨点医院流感样病例流感病毒感染情况
- Author:
Yongdi HU
1
;
Wenxia DOU
1
;
Lunhui XIANG
1
;
Ya GAO
1
;
Xiaofeng LIU
1
;
Fan HE
1
Author Information
1. Shanghai Baoshan District Center for Disease Control and Prevention (Shanghai Baoshan District Health Supervision Institute), Shanghai 201901, China
- Publication Type:Journal Article
- Keywords:
influenza;
influenza-like illness;
influenza A;
influenza B;
sentinel surveillance
- From:
Shanghai Journal of Preventive Medicine
2025;37(7):606-610
- CountryChina
- Language:Chinese
-
Abstract:
ObjectiveTo investigate the influenza virus infection status of influenza-like illness (ILI) at a sentinel hospital in Baoshan District of Shanghai, to explore the seasonal patterns of influenza, so as to provide a scientific basis for influenza prevention and control in Baoshan District of Shanghai. MethodsSurveillance data and pathogenic testing results of ILI from the monitoring year of 2015 to 2023 were collected from the sentinel hospital to describe the seasonal epidemic characteristics of influenza in this district. ResultsThe proportion of ILI visits to sentinel hospital in Baoshan District of Shanghai showed an upward trend from 2015 to 2023 (Z=2.598, P=0.09). The positive rate of influenza virus in ILI was 20.43% (1 761/8 621), of which 14.17% were positive for influenza A virus, including 8.43% for influenza A/H3N2 and 5.74% for influenza A/H1N1. The positive rate of influenza B virus was 6.25%, of which the positive detection rate of influenza B/Victoria virus was 5.35%, while that of influenza B/Yamagata virus was 0.90%. Influenza B/Yamagata virus was not detected in 2019‒2023. The highest positivity rate was observed in the 5‒<15 years age group (25.57%). The positive rate of ILI was lower in males (19.90%) than that in females (20.90%). There were three patterns of influenza epidemic in the district: with year-round circulation in 2016‒2017 and 2021‒2022; with bimodal peaks in 2015‒2016, 2017‒2018 and 2022‒2023; and with one peak in 2018‒2019 and 2019‒2020. The positive rate of influenza virus exhibited seasonal variations, with influenza A virus predominated in summer and autumn. However, influenza B virus showed an increase in spring and winter. ConclusionThe influenza epidemic in Baoshan District, Shanghai exhibits diverse patterns with heterogeneous epidemiological characteristics across different age groups and seasons. Notably, children and adolescents aged 5‒<15 years constitute the key target population for influenza prevention and control. Enhanced surveillance and targeted control measures against influenza A/H3N2 lineage viruses are particularly warranted during summer and autumn seasons.
