Stable non-synonymous substitutions on NS gene (NS1 and NS2 proteins) of Qinghai Lake H5N1 influenza virus (Clade 2.2) after successive passages in Muscovy ducks

Although worldwide concern has been raised since the large-scale outbreak of highly pathogenic avian influenza in wild birds at Qinghai Lake,China in 2005,the factors responsible for the ability to kill waterfowl remain unclear. The why and how questions of the H5N1 virus species-jump into its reservoir host need to be answered. In this report we test the pathogenicity and adaptation of Qinghai Lake (Clade 2.2) isolate to Muscovy ducks for further understanding of this virus. The isolate was highly pathogen...