2010—2019年上海市徐汇区流感样病例流行特征及趋势分析

Epidemiological characteristics and trend analysis of influenza-like cases in Xuhui District of Shanghai from 2010 to 2019

【目的】分析徐汇区2010—2019年流感样病例(ILI)的流行病学特征和发病趋势,了解该区的流感流行特点和规律,为今后的流感防控工作提供科学依据。【方法】对"中国流感监测信息系统"收集的2010—2019年徐汇区ILI监测数据进行统计学描述和趋势分析。【结果】2010—2019年总流感样病例百分比(ILI%)为0.54%,各年ILI%在0.35%~1.14%之间波动,报告ILI以25~59岁组为主,占总数的54.50%。2010—2019年共检测9 053份标本,其中阳性2 137份,阳性率为23.61%,以甲型流感病毒为主(67.62%)。ILI%和流感病毒核酸检测阳性率呈现夏季和冬季流行高峰特征,两者呈正相关(r=0.666,P<0.01)。2010—2019年ILI%和流感病毒核酸阳性率均呈现逐年下降趋势。【结论】徐汇区流感发病呈现下降趋势,有夏季和冬季2个流行高峰,25~59岁组是发病重点人群。流感病毒优势毒株呈交替规律性变化,夏季流行高峰以甲型H3N2流感病毒为主,冬季流行高峰以甲型H1N1型和乙型流感病毒为主。

[Objective]To analyze the epidemiological characteristics and incidence trend of influenza-like illness in Xuhui District from 2010 to 2019,in order to understand the patterns of influenza epidemic of Xuhui District,and to provide evidence for the prevention and control of influenza in the future.[Methods]Surveillance data of influenza-like illness(ILI)in Xuhui District from 2010 to 2019 were collected from the National Influenza Surveillance System for statistical description and trend analysis.[Results]From 2010 to 2019,the overall proportion of influenza-like illness was 0.54%.The annual proportions of ILI were between 0.35%~1.14%.The majority of cases were reported in age group of 25~59,accounted for 54.50% of the total ILI.A total of 9 053 throat swab specimens from ILI patients were collected and tested,from which 2 137 specimens were positive,with a positive rate of 23.61%.The most frequent subtype of influenza virus detected was influenza A virus(accounting for 67.62%).The proportion of ILI and the positive rate of influenza virus nucleic acid detection reached the peak in summer and winter over time.There was a positive correlation between the proportion of ILI and the positive rate of influenza(r=0.666,P<0.01).From 2010 to 2019,both ILI% and nucleic acid positive rate of influenza virus showed a downward trend.[Conclusion]The incidence of influenza shows a downward trend in Xuhui District,with two peaks in summer and winter.The most susceptible individuals are in 25~59 age group.The dominant strains of influenza virus alternate regularly,influenza A(H3N2)dominate the summer epidemic peak while the epidemic peak in winter is dominated by influenza A(H1N1)and influenza B.