2009～2010年北京地区甲型流感监测分析

Surveillance of influenza A virus in Beijing from 2009-2010

目的了解北京地区2009～2010年甲型流感的流行情况,为预防和控制北京地区甲型流感的流行提供依据。方法以解放军总医院作为哨点医院,用Real-ti me RT-PCR从流感样病例咽拭子中检测甲型流感病毒,监测甲型流感病毒在该地区的流行情况。结果 2 134份标本中甲型流感病毒阳性575份,阳性率为26.94%,其中甲型H1N1占46.26%,季节性H3N2型占40.70%,H1N1型占3.30%,未分型占9.74%。甲型流感病毒感染者年龄分布峰值在20～30岁之间,感染时间分布的2个峰值在第37周和47周,分别以H3N2型和甲型H1N1流感病毒为主。结论 2009～2010年北京地区流行的甲型流感病毒以甲型H1N1为主,其次是H3N2,甲型H1N1取代了季节性H3N2流感病毒在冬季的流行。应加强对甲型流感病毒的监测,密切关注甲型H1N1流感病毒的抗原变化有重要意义。

Objective To study the prevalence of influenza A virus in Beijing and to provide basic information to prevent and control influenza epidemics.Methods Nasopharyngeal swabs from patients with symptom of influenza-like illness（ILI） were collected in a sentinel hospital from August 2009 to March 2010.Influenza A virus was detected and further subtyped using real-time RT-PCR.Results In total,2 134 swabs were collected and 575 were positive for the influenza A virus.Pandemic A（H1N1） was the predominant strain,accounting for 46.26%（266/575） of the swabs with influenza virus.This was followed by A（H3N2）（40.70%,234/575）,an unknown subtype（9.74%,56/575）,and seasonal A（H1N1）（3.30%,19/575）.Compared to seasonal A（H3N2）,pandemic A（H1N1） was most prevalent in younger individuals.Patients with A（H3N2） infection had a median age of 28 years,and patients with pandemic A（H1N1） had a median age of 24 years.From 2009-2010,there were two peaks in influenza A virus infection in weeks 37 and 47.The predominant strains were A（H3N2） and pandemic A（H1N1）,respectively.Conclusion Pandemic A（H1N1） was more prevalent than seasonal A（H3N2） in the winter of 2009.Surveillance of human influenza should be enhanced by monitoring antigenic changes in the influenza virus.