【摘要】 目的 了解2016—2025年四川省南充市流行性感冒(流感)流行特征，为制定流感防控措施提供参考。方法通过中国疾病预防控制信息系统收集报告日期为2016年1月1日—2025年12月31日、现住址为南充市的流感确诊病例和临床诊断病例资料；通过中国流感监测信息系统收集同期南充市流感监测哨点医院流感样病例(ILI)就诊例数和病原学监测结果。描述性分析2016—2025年南充市流感病例的人群分布、时间分布和地区分布特征，以及ILI病原学监测结果。采用平均年度变化百分比(AAPC)分析2016—2025年流感报告发病率变化趋势；采用季节指数(SI)分析流感发病季节特征；采用空间自相关分析流感发病的时空分布特征。结果 2016—2025年南充市报告流感病例133 861例，年均报告发病率为240.30/10万，报告发病率总体呈上升趋势(AAPC=82.765%,P<0.05)。1—3月、11—12月SI均>100%，为流感高发期。男性流感年均报告发病率高于女性(P<0.05)。0～<15岁、≥60岁组流感年均报告发病率较高，分别为974.89/10万、132.33/10万。以学生为主，46 600例占34.81%。阆中市报告病例数、年均报告发病率均居首位，分别为23 659例、378.85/10万。2016—2025年南充市流感病例分布总体呈随机分布；2017年高坪区为低-高聚集区，2018年西充县为低-高聚集区，2020年、2021年营山县为低-低聚集区，2025年顺庆区为高-低聚集区。2016—2025年南充市ILI流感病毒阳性检出率为15.03%，型别为乙型Victoria系、甲型H1N1亚型、甲型H3N2亚型和乙型Yamagata系。结论 2016—2025年南充市流感报告发病率呈上升趋势；冬春季高发，男性、儿童青少年、老年人和学生是高发群体，阆中市、顺庆区是发病高风险地区；流感病毒各亚型呈交替或共同流行。更多还原

【Abstract】 Objective To investigate the epidemiological characteristics of influenza in Nanchong City, Sichuan Province from 2016 to 2025, so as to provide references for formulating targeted influenza prevention and control strategies.Methods Data on confirmed and clinically diagnosed influenza cases with current residence in Nanchong City reported from January 1, 2016 to December 31, 2025 were extracted from the Chinese Disease Prevention and Control Information System. The number of influenza-like illness(ILI) visits and etiological monitoring data from sentinel hospitals in Nanchong City during the same period were collected through the Chinese National Influenza Surveillance Information System. Descriptive analysis was conducted to clarify the population, temporal and regional distribution of influenza cases as well as etiological results of ILI. The average annual percent change(AAPC) was used to analyze the trend of reported influenza incidence. Seasonal index(SI) was used to identify seasonal epidemic characteristics, and spatial autocorrelation analysis was used to explore the spatiotemporal distribution of influenza incidence. Results A total of133 861 influenza cases were reported in Nanchong City from 2016 to 2025, with an average annual reported incidence of 240.30/10~5, showing a rising trend(AAPC=82.765%, P<0.05). The periods from January to March and November to December were the peak epidemic seasons with SI values over 100%. The average annual reported incidence was higher in males than in females(P<0.05). The age groups of 0-<15 years and ≥60 years had relatively higher incidence of 974.89/10~5 and 132.33/10~5 respectively. Students constituted the predominant population, accounting for 34.81%(46 600 cases). Langzhong City ranked first in both total reported cases(23 659 cases) and average annual reported incidence(378.85/10~5). The overall spatial distribution of influenza cases was random. Low-high clusters were found in Gaoping District in 2017 and Xichong County in 2018; low-low clusters were observed in Yingshan County in 2020 and 2021; high-low clusters existed in Shunqing District in 2025. From 2016 to 2025, the overall positive detection rate of influenza virus among ILI was 15.03%, including influenza B Victoria lineage, influenza A H1N1 subtype, influenza A H3N2 subtype and influenza B Yamagata lineage. Conclusions The reported incidence of influenza in Nanchong City presented an upward trend from 2016 to 2025, with epidemics predominantly occurring in winter and spring.Males, children and adolescents, the elderly and students are high-risk population, while Langzhong City and Shunqing District are high-incidence areas. Different influenza subtypes circulate alternately or concurrently in this region.更多还原