2023~2025年重庆市沙坪坝区流感样病例季节性流行特征及病原学监测分析

Analysis on Seasonal Epidemic Characteristics and Etiological Surveillance of Influenza-Like Illness Cases in Shapingba District, Chongqing, 2023~2025

摘要: 目的：分析2023~2025年重庆市沙坪坝区流感哨点监测数据的特征，探讨不同季节、年龄人群流感与新冠病毒的流行差异，为优化哨点监测、疫苗接种及呼吸道传染病分层防控提供依据。方法：收集辖区3家区域综合哨点医院9295份流感样病例(influenza-like illness, ILI)鼻咽拭子开展流感、新冠核酸检测，采用描述流行病学分析人群与时间分布，运用χ²检验、多因素Logistic回归解析感染影响因素。结果：流感总阳性率19.41% (甲流16.79%，乙流2.61%)，新冠阳性率9.36%，未检出二者共感染。流感冬春季高发，新冠春夏季高发。多因素回归显示，以≥60岁人群、夏季为参照，5~14岁、冬季是甲流感染独立危险因素；25~59岁、冬季(Firth回归校正)为乙流独立危险因素；15~24岁青年为新冠感染独立危险因素。结论：沙坪坝区流感、新冠交替流行；流感防控重点为冬春季5~14岁儿童青少年及25~59岁成人，新冠防控重点为春夏季15~24岁青年；应依据病毒型别、季节、年龄开展分层靶向防控，提升呼吸道传染病预警干预精准度。

Abstract: Objective: To analyze the characteristics of influenza sentinel surveillance data in Shapingba District, Chongqing from 2023 to 2025, explore the epidemiological differences of influenza and SARS-CoV-2 across seasons and age groups, and provide evidence for optimizing sentinel surveillance, vaccination, and stratified prevention-and-control of respiratory infectious diseases. Methods: Nasopharyngeal swabs were collected from 9295 influenza-like illness (ILI) patients at three regional comprehensive sentinel hospitals within the jurisdiction for nucleic acid detection of influenza and SARS-CoV-2. Descriptive epidemiology was applied to analyze demographic and temporal distributions. The χ² test and multivariate Logistic regression were used to identify influencing factors for infections. Results: The overall positive rate of influenza was 19.41% (16.79% for influenza A, 2.61% for influenza B), and the positive rate of SARS-CoV-2 was 9.36%. No co-infections of the two viruses were detected. Influenza peaked in winter and spring, whereas SARS-CoV-2 prevailed in spring and summer. Multivariate regression showed that taking people aged ≥ 60 years and summer as references, age 5~14 years and winter were independent risk factors for influenza A infection; age 25~59 years and winter (adjusted by Firth regression) were independent risk factors for influenza B infection; young adults aged 15~24 years represented an independent risk factor for SARS-CoV-2 infection. Conclusion: Influenza and SARS-CoV-2 circulated alternately in Shapingba District. Priority populations for influenza prevention were children and adolescents aged 5~14 years as well as adults aged 25~59 years in winter and spring, while young adults aged 15~24 years in spring and summer should be highlighted for SARS-CoV-2 prevention. Stratified and targeted prevention—and-control measures should be implemented according to virus subtype, season and age to improve the precision of early warning and intervention for respiratory infectious diseases.