甲流病毒的出现导致季节性H1N1流感病毒所受的纯化选择增强

Emerged Pdm09 Influenza Virus Increased Purifying Selection of Seasonal H1N1 Influenza Virus

为了探明2009年5月甲流在中国暴发几个月后,既往在人群中流行多年的季节性H1N1流感病毒流行强度突然下降,并且最后在人群中消失的原因,本文对2006～2011年中国季节性H1N1流感病毒的HA1进行测序,然后计算HA1所受选择压力,得到季节性H1N1流感病毒在不同时段的ω值。结果表明季节性流感H1N1流感病毒在甲流暴发前ω=0.36,暴发后ω=0.28。统计学分析表明暴发前和暴发后两组的ω值有显著性差异(t检验,P<0.05)。因此,中国季节性H1N1流感病毒在甲流大流行后受到更强的纯化选择,可能是导致其从人群中消失的主要原因之一。

Pdm09 virus outbreak occurred in China's Mainland in May 2009, a few months later, the prevalence of seasonal HINI（sH1N1） influenza virus that already circulated in human for tens of years began to decline and disappeared afterwards. To identify the reason for the rapid decline of sH1N1 in China's Mainland, we sequenced the HA1 of sH1N1 during 2006-2011, and then analyzed the selective pressure in different phases. Our results showed before Pdm09 outbreak, the ω value was 0.36 while after Pdm09 out-break the ω value was 0. 28 and significant difference （t test, P;O. 05） was identified. We concluded that sH1N1 obtained stronger purifying selection after Pdm09 outbreak in China. This might one of the major reasons causing the disappearance of sHiN1 in human.