2009至2017年西安市流感病毒分型和流行特征

Types and epidemiological characteristics of influenza virus in Xi＇ an during 2009 to 2017

目的了解西安市流感病毒的分型和流行特征。方法收集2009年8月至2017年12月西安市5家流感监测哨点医院的流感样病例咽拭子标本21856份，采用实时荧光定量PCR法进行流感病毒核酸检测和分型，采用鸡胚细胞（或）犬肾传代细胞系（MDCK）分离病毒，同时将流感样病例分为7个年龄组。采用SPSS18．0软件分析流感病毒监测结果和数据。结果21856份流感样病例中，流感病毒阳性标本数为3539份，阳性率为16．19％，其中A型流感病毒（包括季H1型、季H3型、新甲H1型、H7型）占62．39％（2208／3539），B型流感病毒（Victoria、Yamagata和B型未分型）占37．50％（1327／3539），混合型为0．11％（4／3539）。不同年份流感病毒阳性检出率差异具有统计学意义（x2=357．65，P〈0．01）。1至3月A型主要流感病毒占49．07％（947／1930）、B型占50．93％（983／1930），10至12月A型流感病毒占78．07％（1061／1359），B型占21．93％（298／1359）。1至3月和10至12月A型主要流感病毒和B型流感病毒构成比差异具有统计学意义（x2=550．06，P〈0．05）。0～3岁，〉3～7岁，〉7～13岁，〉13～18岁，〉18～24岁，〉24—60岁和〉60岁年龄组流感病毒检出阳性率分别为12．61％、19．41％、19．66％、22．98％、14．91％、13．50％和12．84％，差异具有统计学意义（x2=202．52，P〈0．05）。结论西安市流感病毒以A型为主，冬春季为流感病毒高发季节。人群普遍易感，推荐接种流感疫苗。

Objective To analyze the types and epidemiological characteristics of influenza virus in Xi＇ an during 2009 to 2017. Methods A total of 21 856 samples of throat swabs from patients with influenza like illness （ILl） were collected from 5 national influenza sentinel surveillance hospitals from August 2009 to December 2017. Influenza virus nucleic acid was detected by real-time fluorescence quantitative PCR and virus types were confirmed, chick-embryo cells or Madin-Darby canine kidney （MDCK） cells were used to isolate influenza virus. SPSS 18.0 software was used for data analysis. Results The positive detection rate of influenza virus was 16. 19% （3 539/21 856）, the seasonal influenza A virus subtypes including H1, H3, the new type Hland H7 accounted for 62.39% （2 208/3 539）, influenza B virus subtypes including Victoria, Yamagata and unclassified type B accounted for 37.50% （ 1 327/ 3 539）, and the mixed influenza virus infection accounted for 0. 11% （4/3 539）. The positive rate of influenza virus detected in different years was significantly different （X2 = 357. 651, P 〈 0.01 ）. During January to March the major influenza A viruses accounted for 49.07% （947/1 930）, influenza B viruses accounted for 50.93% （983/1 930 ） ; during October to December, the influenza A viruses accounted for 78.07% （1 061/1 359）, and influenza B viruses significant difference in composition of type A virus accounted for 21. 93% （298/1 359） ; there was and type B virus between different seasons （x2 =550. 06, P 〈 0.05 ）. The positive detection rate of influenza virus in patients with ILI of age groups 0-3 years, 〉3-7 years, 〉 7-13 years, 〉 13-18 years, 〉 18-24 years, 〉 24-60 years and 〉 60 years were 12. 61%, 19. 41%, 19.66%, 22.98%, 14.91%, 13.50% and 12.84%, respeetively （X2 =202.52, P 〈 0.05 ）. Conclusion Influenza A virus is common in Xi＇ an,winter and spring are the peak seasons for influenza epidemics. It is reeommended for suseeptible people to take influenza vaeeination.