黑龙江省老年人群流行性感冒流行特征

Epidemiological characteristics of influenza among the elderly in Heilongjiang Province

目的了解2017—2021年度(2017年4月—2022年3月)黑龙江省老年人群流行性感冒(流感)流行特征,为老年人群流感防控提供参考。方法通过中国流感监测信息管理系统收集2017—2021年度黑龙江省≥60岁流感样病例(ILI)监测资料,描述性分析ILI病例的时间分布和流感病毒检测结果。结果2017—2021年度黑龙江省报告≥60岁ILI病例26908例,ILI%为0.17%。2017—2021年度ILI%呈上升趋势(χ^(2)_(趋势)=268.554,P<0.001),2019年度和2020年度的第3—7周为流行高峰。流感病毒阳性率为6.80%,2017—2021年度流感病毒阳性率呈下降趋势(χ^(2)_(趋势)=425.268,P<0.001),主要型别为A(H1N1)pdm09、A(H3N2)、B/Victoria和B/Yamagata,分别占46.82%、22.79%、12.11%和18.28%,各监测年度交替流行。阳性标本检出高峰为12月至次年3月。鹤岗市、黑河市和大庆市流感病毒阳性率较高,分别为12.35%、11.47%和11.07%。2017—2021年度ILI%与流感病毒阳性率间无显著相关关系(rs=-0.800,P=0.104)。结论2017—2021年度黑龙江省≥60岁人群ILI%呈上升趋势,流行高峰在冬春季,A(H1N1)pdm09、A(H3N2)、B/Victoria和B/Yamagata交替流行,ILI%与流感病毒阳性率无明显相关性。

Objective To investigate the epidemiological characteristics of influenza among the elderly in Heilongjiang Province from 2017 to 2021(April 2017 to March 2022),so as to provide insights into influenza control among the el-derly.MethodsThe data pertaining to surveillance of patients with influenza-like illness(ILI)at ages of 60 years and older in Heilongjiang Province from 2017 to 2021 were retrieved from Chinese Influenza Surveillance Information Man-agement,and the temporal distribution of ILI cases and the results of influenza virus tests were descriptively analyzed.ResultsTotally 26908 ILI cases at ages of 60 years and older were reported in Heilongjiang Province from 2017 to2021,with an ILI prevalence rate of 0.17%.The prevalence of ILI appeared a tendency towards a rise in Heilongjiang Province from 2017 to 2021(χ^(2)_(trend)=268.554,P<0.001),and the epidemic peaked in the 3rd to 7th weeks of 2019 and2020.The overall positive rate of influenza virus was 6.80%,and the positive rate of influenza virus showed a tenden-cy towards a decline from 2017 to 2021(χ^(2)_(trend)=425.268,P<0.001).Influenza A(H1N1)pdm09(46.82%)and A(H3N2)(22.79%),as well as influenza B virus lineages B/Victoria(12.11%)and B/Yamagata(18.28%)were predominant types,which changes among the study period.The detection of influenza virus-positive samples peaked from December to March of the next year,and a high positive rate of influenza virus was detected in Hegang(12.35%),Heihe(11.47%)and Daqing cities(11.07%).There was no significant correlation between the prevalence of ILI and the positive rate of influenza virus in Heilongjiang Province from 2017 to 2021(rs=-0.800,P=0.104).ConclusionsThe prevalence of ILI appeared a tendency towards a rise among the elderly at ages of 60 years and older in Heilongjiang Province from2017 to 2021,and the epidemic peaked in winter and spring.Influenza A(H1N1)pdm09,A(H3N2),B/Victoria,B/Yamagata were alternately prevalent and there was no obvious correlation between ILI prevalence and the positive rate of influenza virus.