2018-2020年上海市宝山区流行性感冒流行病学及病原学特征分析

Epidemiologic and etiological characteristics of influenza in Baoshan district of Shanghai,2018-2020

目的描述上海市宝山区2018—2020年流行性感冒(流感)的流行病学特征,为当地流感防控工作提供有力的科学依据。方法对上海市宝山区2018—2020年流感样病例(ILI)报告数据和病原学监测数据进行系统分析。结果上海市宝山区2018和2019年均在冬、春季出现较小的ILI流行峰,在夏、秋季较为平稳;相较于2018年和2019年,2020年流感样病例占比(ILI%)呈明显上升趋势(χ^(2)=1340,P<0.01),并在2020年1月23日达到最高峰,在春、夏、秋季均明显升高;ILI%最高的人群为25~59岁青、中年人群,其次为0~15岁的儿童;2018—2020年共检测ILI病例标本3141份,流感病毒阳性497份,总阳性率为15.82%,2019年阳性率最高(29.51%),2020年最低(5.00%,χ^(2)=241.18,P<0.01);2018年流行的流感病毒毒株以甲型H1N1型为主(7.92%),2019年为季节性H3型(11.77%),2020年为B型(3.39%)。结论上海市宝山区2018—2019监测年度流感流行强度较平稳,而在2020年新型冠状病毒肺炎暴发初期ILI%增加趋势明显,但是2020年全年ILI标本毒株检测阳性率则非常低。

Objective To describe the epidemiological characteristics of influenza in Baoshan district of Shanghai from 2018 to 2020,and provide a strong scientific basis for the local prevention and control of influenza.Methods The incidence data and the etiological surveillance data of influenza-like illness(ILI)in Baoshan from 2018 to 2020 were systematically analyzed.Results In 2018 and 2019,the incidence of ILI was higher in winter and spring,and was stable in summer and autumn in Baoshan.Compared with 2018 and 2019,The proportion of ILI in 2020 increased significantly(χ^(2)=1340,P<0.01),and reached the peak on January 23,2020.The ILI proportion increased significantly in spring,summer and autumn.The highest ILI proportion was found in young and middle-aged people aged 25−59 years,followed by children aged 0−15 years.A total of 3141 samples of ILI cases were detected from 2018 to 2020,and 497 were positive for influenza virus with the positive rate of 15.82%.The positive rate was highest in 2019(29.51%)and lowest in 2020(5.00%)(χ^(2)=241.18,P<0.01).Influenza A(H1N1)virus was predominant in 2018(7.92%),influenza A(H3N2)virus was predominant in 2019(11.77%),and influenza B virus was predominant in 2020(3.39%).Conclusion The influenza activity in Baoshan was stable during 2018−2019,and the ILI proportion increased significantly in the early stage of COVID-19 outbreak in 2020,but the positive rate in the detection of ILI cases’samples in the whole year of 2020 was very low.