Objective: Analysis of the characteristics of influenza epidemic in Anhui Province and quantification of the impact of different factors on influenza occurrence, providing scientific basis for better influenza prevention and control. Methods: Descriptive analysis and factor analysis were conducted on influenza-like illness (ILI) cases and RT-PCR results in Anhui Province from 2013 to 2021 using data from China's Influenza Monitoring Information System. Results: The percentage of influenza-like illness (ILI%) of sentinel hospitals in Anhui Province from April 1, 2013 to March 31, 2021 was 3.80% (1 209 142/31 779 987), showing an overall increasing trend, with a relatively high proportion in 2017-2018 at 4.30% (191 148/4 448 211). The proportion of ILI cases in infants and young children aged 0-4 years was a relatively high at 54.14% (654 676/1 209 142), and the highest ILI% was observed in Fuyang City, Anhui Province (6.25%, 236 863/3 788 863). Laboratory monitoring results showed that the positive rate of ILI cases in sentinel hospitals in 8 influenza monitoring years was 16.38% (34 868/212 912), showing an increasing trend year by year, with a relatively proportion in 2017-2018 at 26.19% (6 936/26 488). The detection rate of school-age children aged 5-14 years was a relativelyhigh at 28.81% (13 869/48 144), and the positive rate was a relatively high in Wuhu City among the 16 cities, reaching 22.01% (2 693/122 237). Influenza activity showed a single peak in winter-spring and alternating double peaks in winter-spring and summer, with different subtypes alternating, and A (H3N2) was the dominant subtype in summer. The results of a multiple logistic regression model showed that the positive rate was higher in 2017-2018, among children aged 5-14 years, in winter, and in southern Anhui. Conclusions: Influenza epidemic in Anhui Province has a clear seasonal pattern, and the ILI% and detection rate have shown an upward trend from 2013 to 2021. Therefore, it is suggested to ensure vaccine supply before the winter-spring influenza season arrives, and to strengthen vaccine uptake and health education to avoid the risk of infection during the peak period of influenza.
目的： 分析安徽省流感流行特征与量化不同因素对流感发生的影响，为更好地开展流感防控工作提供科学依据。 方法： 资料来源于中国流感监测信息系统2013年4月1日至2021年3月31日安徽省网络报告数据，对2013-2021监测年度安徽省的流感样病例（ILI）和RT-PCR结果进行描述性分析和影响因素分析。 结果： 安徽省2013年4月1日至2021年3月31日哨点医院ILI就诊百分比（ILI%）为3.80%（1 209 142/31 779 987），总体呈上升趋势，其中2017-2018监测年度较高，为4.30%（191 148/4 448 211）。0~4岁婴幼儿的ILI构成比较高（54.14%，654 676/1 209 142）；安徽省阜阳市ILI%较高（6.25%，236 863/3 788 863）。实验室监测结果显示，8家流感监测年度哨点医院ILI中流感阳性率为16.38%（34 868/212 912），总体呈逐年上升趋势，其中2017-2018监测年度较高，为26.19%（6 936/26 488）。5~14岁学龄儿童阳性率较高（28.81%，13 869/48 144），16个城市中芜湖市阳性率较高（22.01%，2 693/122 237）。流感活动呈现冬春季单峰与冬春季、夏季双峰的交替，且各亚型交替流行，夏季流感优势亚型为A（H3N2）亚型。多因素logistic回归模型结果显示，2017-2018监测年度、5~14岁儿童、冬季、皖南地区的阳性率更高。 结论： 2013-2021监测年度安徽省流感流行具有明显的季节性，且在2013-2021监测年度ILI%和流感阳性率呈现上升趋势。因此，提示应在冬春流感季到来之前保障疫苗供应，同时加强疫苗接种健康教育，以避免流感高发期的感染风险。.