2010-2015年湖北省H3N2亚型流感病毒抗原漂移分析

目的 了解2010-2015年湖北省H3N2亚型流感病毒流行特征、基因进化和抗原漂移情况。方法 通过2010-2015年湖北省H3N2亚型流感病毒核酸检测阳性率划分流行高峰，分析各流行高峰病毒的阳性数、分离数和进化簇分布，结合抗原决定簇氨基酸突变位点和三维建模数据，分析3C.2a簇病毒抗原决定簇氨基酸突变位点变化情况。结果 2010-2015年湖北省H3N2亚型流感病毒存在8个流行高峰，流行高峰会受到其他型别流感流行的影响，3C.2a簇病毒主要在第Ⅶ流行高峰后流行，与3C.3a簇病毒在HA蛋白3处抗原决定簇上存在7处不同氨基酸突变位点，3C.2a簇病毒159Y-160T位点和3C.3a簇病毒159S-160K位点在三维模拟结构图中差异明显。结论 2010-2015年湖北省H3N2亚型流感病毒进化簇不断进化，加强对近期3C.2a簇病毒的进化学监测和抗原漂移分析，有助于提高湖北省流感病原学和流行病学监测水平和能力。

Analysis of antigen drift of influenza A (H3N2) virus in Hubei, 2010-2015

Objective To understand the epidemiological characteristics,evolution and antigenic drift of influenza A (H3N2) virus in Hubei province during 2010-2015.Methods The epidemic peaks were divided by using the positive rate of influenza A (H3N2) virus in Hubei during this period.Positive number,isolation number and phylogenetic trees of the virus were analyzed in every epidemic peaks,then amino acid substitution of antigen was analyzed by using substitution data and homology modeling structures of the HA protein of influenza A (H3N2) clade 3C.2a viruses.Results There were eight epidemic peaks during the variation of influenza A (H3N2) virus in Hubei during 2010-2015.The epidemic peak of influenza A (H3N2) virus would be influenced by epidemics of other influenza viruses.After the seventh epidemic peak,clade 3C.2a virus was most prevalent.Seven amino acid substitutions and their different structures were detected on three major epitopes of HA protein between clade 3C.2a and 3C.3a viruses.There were distinct structure difference in amino acid sites between 159Y-160T (3C.2a virus) and 159S-160K (3C.3a virus).Conclusion Evolution of influenza A (H3N2) virus occurred in Hubei during 2010-2015.It is necessary to strengthen the surveillance for the evolution and analysis of clade 3C.2a virus to facilitate the pathogenic and epidemiological study of influenza in Hubei.