重庆市2016—2020年流感监测分析

Influenza surveillance in Chongqing,2016-2020

目的分析2016—2020年重庆市流感流行病学特征,为流感防控策略的制定提供科学依据。方法通过“中国流感监测信息系统”收集2016年1月至2020年12月重庆市流感样病例报告及病原学监测数据,采用荧光定量RT-PCR方法对流感样病例咽拭子样本进行病原学检测,对流感流行发生时间、地区、人群进行描述性流行病学及统计学分析。结果2016—2020年重庆市报告流感样病例就诊百分比(ILI%)为1.72%,五个年度依次为0.83%,0.83%,3.53%,2.23%,1.20%;流感病毒核酸阳性检出率为14.96%,五个年度分别为13.38%,20.34%,13.97%,23.81%和2.65%,流感流行主要集中在每年的1—3月和10—12月。不同年度ILI%和核酸阳性检出率差异均有统计学意义(P<0.05)。发病高峰为每年冬春季,发病人群以0~<15岁年龄组为主(85.15%),流感病毒阳性检出率最高的是5~<15岁组(19.79%)。不同年度流感流行的优势毒株型别不同,呈现交替循环的规律。结论2016—2020年重庆市流感处于季节性流行水平,流行高峰出现在每年的冬春季,不同亚型流感病毒交替流行,无重大流感疫情发生。流感核酸阳性检出人群以小学生为主,流感的防控应重点关注学校等人群聚集场所,大力推广流感疫苗接种与预防流感的知识宣传,降低流感等呼吸道传染病的发病率。

Objective To analyze the epidemiological characteristics of influenza in Chongqing from 2016 to 2020,so as to provide scientific evidence for control and prevention of influenza.Methods The influenza surveillance data of influenzalike illness(ILI),during Jan.2016 to Dec.2020,were collected through the"China Influenza Surveillance Information System".The throat swab specimens of influenza-like illness(ILI)were detected by using the method of real-time fluorescence quantitative RT-PCR.Descriptive epidemiological analysis was conducted to study the influenza epidemic time,area,and population.Results The proportion of ILI cases was 1.72%in Chongqing between 2016 and 2020.The annual proportions of ILI cases were 0.83%,0.83%,3.53%,2.23% and 1.2%,separately.Totally,the positive rate of influenza virus was 14.96%,and in each year,those were 13.38%,20.34%,13.97%,23.81% and 2.65%.Influenza epidemic was mainly concentrated in January to March and October to December every year.There were significant differences in ILI% and nucleic acid positive rate in different years(P<0.05).The peak of onset was in winter and spring of each year,mainly in 0-<15 years age group(85.15%),but the highest positive rate of influenza virus was in 5-<15 years age group(19.79%).The dominant influenza strains were different in different years,showing the law of alternating circulation.Conclusions The influenza activity in Chongqing was at a seasonal epidemic level from 2016 to 2020.The epidemic peak occurs in winter and spring every year.Different subtypes of influenza viruses were epidemic alternately,and no major influenza epidemic occurred.Primary school students are the main people with influenza nucleic acid positive detection,and influenza prevention and control should focus on schools and other places where people gather.We should vigorously promote the knowledge of influenza vaccination and influenza prevention,and reduce the incidence rate of respiratory infectious diseases such as influenza.