Low pathogenic avian influenza (LPAI) H9N2 viruses have established endemic status in Egyptian poultry populations since 2012. Recently, four cases of human H9N2 virus infections in Egypt demonstrated the zoonotic potential of these viruses. Egyptian H9N2 viruses obtained from 2011 to 2014 phylogenetically grouped into three clusters (1−3) within subclade B of the G1 lineage. Antigenically, a close clustering of the Egyptian H9N2 viruses with other recent G1-B like H9N2 strains and a significant antigenic distance from viruses outside the G1-B lineage was evident. Recent Egyptian LPAIV H9N2 showed a tendency to increased binding with erythrocytes expressing α 2,6-linked sialic acid which correlated with the Q226L amino acid substitution at the receptor binding unit of the hemagglutinin (Q234L, H9 numbering). Sequence analyses of the N2 neuraminidase (NA) revealed substitutions in the NA hemadsorption site similar to the N2 of prepandemic H3N2/1968, but no distinct antigenic or functional characteristics of the H9N2 NA associated with increased zoonotic potential could be identified.

自2012年以来，低致病性禽流感（LPAI）H9N2病毒已在埃及家禽种群中确立了流行状态。最近，埃及有4例人类H9N2病毒感染病例证明了这些病毒的人畜共患病潜力。从2011年至2014年获得的埃及H9N2病毒在系统发育上分为G1世系B子群内的三个簇（1-3）。抗原学上，埃及H9N2病毒与其他最近的G1-B像H9N2毒株紧密聚集，并且与G1-B世系之外的病毒之间存在明显的抗原距离。最近的埃及LPAIV H9N2显示出与表达α2，6-连接的唾液酸的红细胞增加结合的趋势，这与血凝素受体结合单元处的Q226L氨基酸取代有关（Q234L，H9编号）。