北京地区2005—2006年流感病原监测结果与乙型流感病毒HA1序列分析

Influenza surveillance and molecular characterization of influenza B viruses during 2005 -2006 in Beijing

目的：分析2005～2006年冬春季北京地区流感病原监测及乙型流感病毒种系分布情况。方法：采用狗肾传代细胞（MDCK）和鸡胚培养分离流感病毒，经血清学试验鉴定分型。选取部分乙型流感提取病毒RNA，经RT—PCR扩增得到HA1基因片段并进行核苷酸序列测定，用信息软件进行种系发生树分析。结果：共采集流感样病例标本1874份，经MDCK细胞分离到510株流感病毒。其中H1N1亚型244株（47．84％）；H3N2亚型57株（11．18％）；B型209株（40．98％），208株为Victoria系，1株为Yamagata系。对210份细胞分离阳性标本进行鸡胚培养，共分离到流感病毒9株，全部为H1N1亚型。28株B型优势流行株与当年疫苗株不属于同一谱系，相差较远；与新预测（2006～2007年）的疫苗株亲缘关系最近。结论：北京地区2005～2006年冬春季节存在H1N1、H3N2、B型3种流感病毒流行，以H1N1、B型为优势毒株。B型Victoria系优势株正在通过变异逐步在流行中占据主导地位。新预测流感疫苗可对人群产生良好的保护效果。

Objective ：To analyze the data of influenza surveillance and understand B viruses distributing in spring- winter of 2005 -2006 in Beijing. Methods： Viruses were isolated with MDCK cells and Chicken embryo and identified with serological test. The influenza B viruses RNA was extrated by reverse transcriptase and amplified by PCR. The PCR product was purified and nucleotide sequence of HA1 gene analyzed by software. Results：A total of 510 influenza strains were obtained from 1874 clinical samples,including 244 H1N1 （47.84%） ;57 H3N2 （ 11.18% ） ;209 B （40.98%）. Of 209 B viruses, 208 were of Victoria and 1 Yamagata. Preponderant B viruses（Victoria） were different with currently vaccine and they belonged to different evolutionary lineages. But they were similar to 2006 -2007 vaccine. Conclusion：The main type was influenza type A （H1 N1 ） and type B （Victoria） in 2005 -2006 in Beijing. B viruses of Victoria have become preponderant viruses in cycle. The 2006 - 2007 vaccine can provide enough protection.