2015—2022年北京市东城区乙型流感流行特征分析

Analysis of Epidemic Characteristics of Influenza B in Dongcheng District,Beijing from 2015 to 2022

目的通过对2015—2022年北京市东城区乙型流感病毒进行流行病学特征分析,为乙型流感的防控提供基础数据。方法收集北京市东城区2015—2022年流感样病例咽拭子样本,进行实时荧光定量聚合酶链反应(polymerase chain reaction,PCR)检测分型,并将阳性样本进行细胞和鸡胚培养分离病毒,对检测出的乙型流感病毒结果进行描述性流行病学分析。结果2015—2022年北京市东城区共采集流感样病例咽拭子样本14393份,其中甲型流感核酸阳性981份,阳性检出率为6.82%;乙型流感病毒核酸阳性748份,阳性检出率为5.20%,乙型流感病毒Victoria(简称BV)系核酸阳性451份,阳性检出率为3.13%,乙型流感病毒Yamagata(简称BY)系核酸阳性297份,阳性检出率为2.06%。乙型流感病毒主要在每年冬春季流行,并且BV和BY交替流行。不同年龄组间乙型流感病毒阳性检出率比较,差异有统计学意义(P<0.05)。不同性别、不同医院间乙型流感病毒阳性检出率比较,差异无统计学意义(P均>0.05)。乙型流感引起的聚集性发热共20起,其中2017年最多有11起。结论北京市东城区2015—2022年乙型流感传播季节性明显,主要在冬春季,并且BV系和BY系交替流行;5~14岁青少年是东城区乙型流感的重点防控人群,应对家庭、学校加强流感防治宣传工作,普及流感疫苗预防接种,同时加大流感监测工作,及时发现流感病毒流行变化以降低疫情的发生,为流感防控提供科学依据。

Objective To provide basic data for the prevention and control of influenza B by analyzing the epidemio-logical characteristics of influenza B viruses in Dongcheng District of Beijing from 2015 to 2022.Methods Throat swab samples from influenza-like illness cases in Dongcheng District,Beijing from 2015 to 2022 were collected and subjected to real-time fluorescence quantitative polymerase chain reaction(PCR)detection and typing.The positive samples were cultured in cells and chicken embryos to isolate the virus,and a descriptive epidemiological analysis of the detected influenza B virus results was conducted.Results From 2015 to 2022,a total of 14393 throat swab samples were collected from influenza-like cases in Dongcheng District of Beijing,of which 981 were positive for in-fluenza A nucleic acid,with a positive detection rate of 6.82%;748 were positive for influenza B virus nucleic acid,with a positive detection rate of 5.20%.There were 451 nucleic acid-positive copies of the influenza B virus Victoria(BV)line,with a positive detection rate of 3.13%.There were 297 nucleic acid-positive copies of the influenza B vi-rus Yamagata(BY)line,with a positive detection rate of 2.06%.Influenza B virus mainly circulates in winter and spring every year,and BV and BY circulate alternately.There was a statistically significant difference in the positive detection rate of influenza B virus between different age groups(P<0.05).There was no significant difference in the positive detection rate of influenza B virus between different genders and different hospitals(both P>0.05).There were 20 cases of cluster fever caused by influenza B,with a maximum of 11 cases in 2017.Conclusion The seasonality of influenza B transmission in Dongcheng District of Beijing from 2015 to 2022 is obvious,mainly in winter and spring,and the BV line and BY line are alternately prevalent.Adolescents aged 5 to 14 years old are the key group for pre-vention and control of type B influenza in Dongcheng District.Families and schools should strengthen influenza pre-vention and control publicity and popularize influenza vaccination.At the same time,we will increase influenza sur-veillance and promptly discover changes in the prevalence of influenza viruses to reduce the occurrence of epidemics and provide scientific basis for influenza prevention and control.