2015—2020年贵州省流行性感冒流行特征分析

Analysis of epidemiological characteristics of influenza in Guizhou Province in 2015—2020

目的 分析2015—2020年贵州省流行性感冒(流感)监测结果和发病空间分布情况。方法 运用描述性流行病学分析方法,对2015—2020年贵州省流感监测结果进行分析,采用GeoDa 1.16软件进行空间自相关分析。结果 2015—2020年贵州省流感年发病率在9.49~34.74/10万,年平均发病率15.54/10万,发病高峰主要集中在冬春季,贵阳市年平均发病率最高(26.45/10万),发病人群以15岁以下散居儿童居多。暴发疫情的流感病毒类型主要为B型流感病毒。共报告流感样病例734 449例,流感样病例年平均就诊比例7.28%,流感样病例核酸检测样本阳性率12.97%,检出的流感病毒型别有季节性H3N2、甲型H1N1、BV型、BY型和其他型,不同型别的流感病毒检出率差异有统计学意义(P<0.05)。不同型别流感毒株交替流行,其中2015—2017年以季节性H3N2为主,2018年以甲型H1N1为主,2019年B型、季节性H3N2和甲型H1N1共同流行,2020年以BV型为主。2015—2020年贵州省各市/州流感的发病呈随机分布,2015年黔东南州流感发病为低-低聚集。结论 2015—2020年贵州省流感发病总体呈上升趋势,在流感季节来临之前,应及时为散居儿童、学生等重点人群接种流感疫苗,并持续加强各型别流感病毒的流行情况监测。

Objective To analyze the surveillance results and spatial distribution of influenza in Guizhou Province from 2015 to 2020.Method The results of influenza surveillance in Guizhou from 2015 to 2020 were analyzed using descriptive epidemiological method.Spatial autocorrelation analysis was performed using the GeoDa 1.16 software.Results The annual incidence of influenza ranged from 9.49 to 34.74/100000 in Guizhou in 2015—2020,with the mean annual incidence being 15.54/100000,and the peak seasons of influenza being winter and spring.The mean an⁃nual incidence was the highest in Guiyang City(26.45/100000).The disease predominantly affected children under 15 years old and living at home.Influenza B virus was the main type of influenza virus causing the outbreaks.A total of 734449 influenza-like illness(ILI)cases were reported in the period from 2015 to 2020,and the mean annual pro⁃portion of ILI cases visiting a doctor was 7.28%.The respiratory samples of 12.97%of the ILI cases were tested positive in nucleic acid test.The detected subtypes of influenza virus included seasonal A/H3N2,pandemic A/H1N1,influenza B virus of Victoria(BV),and Yamagata(BY)etc.,with statistically significant difference in their de⁃tection rate(P<0.05).The subtypes that caused outbreaks varied across the time.The influenza A/H3N2 subtype was dominant during 2015—2017,the influenza A/H1N1 subtype was dominant in 2018,the influenza B virus,influ⁃enza A/H3N2,and A/H1N1 were co-dominant in 2019,while the BV subtype dominated in 2020.The incident cases of influenza in Guizhou Province during 2015-2020 distributed randomly across the cities/prefectures.There was a low-low clustering of the incidence of influenza in Qiandongnan Miao and Dong Autonomous Prefecture in 2015.Conclusions The incidence of influenza was generally on the rise in Guizhou Province during 2015—2020.Thus,key populations including children living at home and students should be vaccinated timely before the influenza seasons,and surveillance of the prevalence of different subtypes of influenza virus has to be continuously strengthened.