2018—2022年重庆市万州区流感暴发疫情特征分析

Epidemiological Characteristics on Outbreaks of Influenza in Wanzhou of Chongqing from 2018 to 2022

目的:分析重庆市万州区流感暴发疫情流行特征,为制定流感防控策略提供参考。方法:收集2018—2022年中国流感监测信息系统中万州区报告的流感暴发疫情相关资料,描述分析发病人群病原学及三间分布特征。结果:2018—2022年万州区共报告疑似流感样病例聚集疫情55起,实验室确证51起,累计发病4 760例,罹患率为4.19%。其中,A (H1N1)型20起,B (Victoria)型15起,A (H3N2)型10起,A (H1N1、H3N2)型混合感染6起。疫情发生高峰期为每年的3月和12月,报告疫情数量占全部疫情数量的比例分别为54.90%(28/51)和23.53%(12/51);疫情暴发场所主要集中在小学和中学,报告疫情数量占全部疫情数量的比例分别为72.55%(37/51)和17.65%(9/51)。logistic回归分析结果显示,毒株型别和介入时间是流感暴发疫情持续时间的显著影响因素,OR大小分别为87.897 (95%CI为7.478~1033.815)、0.085 (95%CI为0.014~0.505)。结论:2018—2022年万州区流感暴发疫情由A (H1N1)型、A (H3N2)型、B (Victoria)型交替流行引起,主要发生在冬春季,高危人群为中小学人群。A型流感病毒引起的暴发疫情规模相对较大、持续时间相对较长,早介入对疫情控制具有较大影响。

OBJECTIVE To analyze the epidemiological characteristics of infectious diseases influenza outbreaks in Wanzhou of Chongqing,and provide a scientific basis for prevention and control strategies.METHODS The data on influenza outbreaks in schools in Wanzhou of Chongqing from 2018 to 2022 from the National Emergency Public Health Events Information Management System and on-site epidemiological surveys were collected and analyzed using descriptive epidemiology method.RESULTS From 2018 to 2022,55 outbreaks of influenza cases were reported and 51 were confirmed in the laboratory,with a cumulative incidence of 4760 cases and an incidence rate of 4.19%(4760/113665).Among them,there were 20 outbreaks of type A pdm09(H1N1),15 outbreaks of type B(Victoria),10 outbreaks of type A(H3N2)and 6 outbreaks of mixed infection of type A(H1N1)pdm09/A(H3N2).The epidemic mainly occurred in March and December,accounting for 54.90%(28/51)and 23.53%(10/51)respectively.The incidence of the epidemic is mainly concentrated in primary and secondary schools,accounting for 72.55%(37/51)and 17.65%(9/51)respectively.Logistic regression analysis showed that virus type and intervention time were significant factors affecting the duration of influenza outbreaks,and the OR accounted for 87.897(95%CI:7.478~1033.815)and 0.085(95%CI:0.014~0.505)of the total number of outbreaks,respectively.CONCLUSION The influenza outbreak in Wanzhou District mainly occurs in winter and spring,and the high-risk population is the primary and secondary school population.Type A and type B influenza virus showed alternating change with seasons.Among them,the outbreak caused by H1N1 virus has a relatively large scale and relatively long duration,and early intervention has a great impact on epidemic control.