【摘要】 目的 分析北京市海淀区流感发病强度变化及不同型别流感病毒的流行特征，为流感防控提供依据。方法 收集2017—2024年北京市海淀区哨点医院流感样病例（influenza-like illness,ILI）病原学监测数据，分析病毒分布特征、时间序列季节性以及不同型别流感病毒变迁情况。结果 2017年第27周至2024年第26周，北京市海淀区哨点医院ILI病毒阳性率为17.94%(1 650/9 196)。甲型流感病毒阳性率（11.83%）高于乙型（6.11%）。2018—2019监测年度病毒阳性率最高（32.21%,267/829）,2020—2021监测年度最低（0.12%,1/861）。25～<60岁人群阳性率最高（19.81%,1 150/5 804）。流感活动呈现冬季单峰，流行高峰多出现在第47周至次年第16周，流感病毒亚型交替流行。不同年份、年龄和季节流感阳性率差异有统计学意义（χ~2=366.627、45.829、945.196,P<0.001）;2018—2019监测年度后，未再检测到乙型Yamagata系。甲型H3N2亚型和乙型Victoria系成为优势毒株。结论 2017—2024年北京市海淀区流感主要发生在冬春季节，25～<60岁人群是重点防控对象。应持续加强流感病原学监测，并加强流感防控知识及疫苗接种的健康教育，以减少流感感染风险。更多还原

【Abstract】 Objective To analyze the changes in influenza incidence and the epidemiological characteristics of different influenza virus types in Haidian District, Beijing, and provide evidence for influenza prevention and control. Methods Pathogen surveillance data for influenza-like illness(ILI) cases collected from sentinel hospitals in the Haidian District between 2017 and 2024 were analyzed to determine virus distribution characteristics, seasonal trends, and the evolution of different influenza virus types. Results From week 27 of 2017 to week 26 of 2024, the positive rate for ILI cases in sentinel hospitals in Haidian District was 17. 94%(1 650/9 196), with a higher positivity rate for influenza A viruses(11. 83%) compared to influenza B virus(6. 11%). The highest positive rate was recorded in the 2018—2019 monitoring year(32. 21%, 267/829), while the lowest was observed in the 2020—2021 monitoring year(0. 12%, 1/861). The positivity rate was highest among individuals aged 25-<60 years(19. 81%, 1 150/5 804). Influenza activity exhibited a single peak during winter, with epidemics commonly occurring from week 47 to week 16 of the following year and alternating circulation of influenza virus subtypes. The differences in influenza positivity rates across different years, ages and seasons were statistically significant(χ~2=366. 627, 45. 829, 945. 196,P<0. 001). After the 2018—2019 monitoring year, no Yamagata lineage was detected, with H3N2 subtype and B/Victoria lineage becoming the dominant strains. Conclusions Influenza in Haidian District, Beijing, primarily occurs during the winter and spring months, with individuals aged 25-<60 years identified as a key target group for prevention efforts. Continuous enhancement of influenza pathogen surveillance, as well as increased public education on influenza prevention and vaccination, are essential to reduce the risk of influenza infection.更多还原