2005～2006年宁波市甲1亚型流感病毒的病原学及基因特性分析

Etiology and genetic characteristic of influenza(H1N1)virus circulated in Ningbo in 2005～2006

目的了解2005～2006年宁波市流行的甲型流行性感冒病毒A(H1N1)亚型的病原学分子生物学特性。方法将2005～2006年分离的流感病毒进行血清学分型,挑选H1N1亚型流感病毒的代表株进行血凝素基因(HA1)片断的核苷酸序列测定,分析抗原变异情况。结果H1N1亚型在2005年3月起在宁波市开始活动加强,同年9月起逐渐形成优势成为主要的流行株。病毒核苷酸序列测定结果,2005年3～4月流行的H1N1与9月以后流行的H1N1氨基酸序列有较大的差异,两者为不同性状的毒株。而且后者的氨基酸序列在2006年又进一步发生了变异,与当前疫苗株A/Newcaledonia/20/1999的抗原性差异进一步加大。同源性降至96.3%。结论H1N1亚型流感病毒重新引起流行并成为优势株与其抗原性的变异及人群中针对这一病毒的免疫力下降有关。

Objective To understand etiology characteristic and Antigenic variant of influenza H1N1 isolated in Ningbo since 2005 to 2006. Methods Serology method was used to identify influenza virus＇s type, representative influenza H1N1 virus was determined nucleotide sequence of hemagglutinin （HA1） gene to analyses difference of the gene. Results The influenza H1N1 virus was begin to recur in March, 2005 in Ningbo, and gradually forms the preponderance in the same year in September. Viral nucleotide sequence determination showed, the amino acid sequence of influenza H1N1 virus circulated In March, 2005 and in September later occur obvious difference, both are two different character viruses. Moreover, the latter＇s amino acid sequence further drift in 2006. Much more enlarges with the vaccine A/New caledonia/20/1999 antigenic difference. The homology falls to 96.3%. Conclusion Influenza H1N1 virus renewably circulated and becomes preponderance may be at the causation of the antigenicity variation and the crowd immunity dropping related in view of this viruses immunity .