2005～2006年宁波市流行性感冒病毒的流行与优势株转换分析

目的：分析2005—2006年宁波市流行性感冒病毒的流行与流感病毒优势株的转换情况。方法：常年监测宁波市流感病毒的流行情况，选取不同时间的各种型别流感毒株进行血凝素基因HA1区核苷酸序列测定，并推导出其氨基酸序列进行基因进化特性分析。结果：2005年1—9月份宁波市的甲型流感以H3N2亚型为流行优势株，而乙型流感在2005年初以Yamagata系占优势。到2005年9月份以后至2006年底甲型流感的H1N1亚型替代了H3N2亚型占据优势株地位，乙型流感也以Victoria系成了优势株。结论：在2005年流感病毒甲、乙型的流行株均发生了亚型或种系的优势转换。流行株的基因特征及抗原性发生了明显的变异，并造成了一定规模的暴发流行。

Analysis on influenza viruses circulating and dominant strain switchover in Ningbo during 2005 ～ 2006

Objective:To analyze Epidemiology characteristic and dominant strain switchover of Influenza viruses in Ningbo during 2005~2006.Methods:Perennial surveillance the circulation of Influenza virus in Ningbo city,representative strains was sequenced based on the difference of the time and type,performed antigenic specificity and phylogenetic analyses of the HA gene.Results:Influenza A virus was H3N2 subtypes and in the influenza B virus the Yamagata-like virus was dominant strain before September 2005.But the dominant position of H3N2 subtypes was substituted by H1N1 subtypes in the Influenza A,and the Yamagata-like virus was substituted by Victoria-like virus in influenza B virus after September of the 2005.Conclusion:The influenza A and B viruses had all occurred switchover of dominant strain in lineage or subtypes.Recent viruses are changing in antigenic and genetic characteristics.