12.04.2013

Gao et al (2013) NEJM

Phylogenetic analysis of all genes of the isolates showed that each gene was of avian origin.  The gene encoding hemagglutinin (HA) shared the highest identity with A/duck/Zhejiang/12/2011(H7N3). The gene encoding neuraminidase (NA) protein was most closely related to A/wild bird/Korea/A14/2011 (H7N9). All six internal genes shared the highest similarity with A/brambling/ Beijing/16/2012-like viruses (H9N2). Phylogenetic results indicated that it was a triple reassortant H7N9 virus. In all three viruses, the HA cleavage site possesses only a single amino acid R (arginine), indicating low pathogenic effects in poultry.