甲型H7N9禽流感病毒的病毒学特征

Virological characteristics of avian influenza A H7N9 virus

摘要:

自2013年2月开始，中国东部省市陆续新发现了由甲型H7N9禽流感病毒引起人感染的病例。研究表明甲型H7N9病毒是一个单纯禽类来源的三元重配体，它的HA和PB2蛋白存在多个特征性突变（包括G186V、Q226L和E627K氨基酸替换），这些突变可能促进了该病毒与人细胞受体的结合以及病毒的复制。目前尚未发现H7N9禽流感病毒发生稳定的人与人间的传播，但不能排除有限人传人的可能。应加强对H7N9病毒的监测，进一步了解该病毒的来源、传播以及可能造成的威胁。

Abstract:

From February 2013, a novel avian influenza A H7N9 virus causing human infection with fatal outcomes has been identified in eastern China. This avian influenza A H7N9 virus is a triple reassortant of viruses that are avian-origin only and it is low pathogenic in poultry. Several characteristic amino acid mutations in HA and PB2 polymerase subunit (including G186V, Q226L and E627K substitution) have been found through sequence analysis, and these mutations probably facilitate binding to human-type receptors and efficient replication in mammals. Other mutations in NA, M2 and NS genes were also found. Although sustained human-to-human transmission has not been conclusively established, limited human-to-human transmission of the H7N9 virus remains possible. Intensified surveillance for the H7N9 virus in humans and animals is needed to answer questions about the viral origin, spread and potential threat.