22.06.2015

Yu et al (2015) J Virol

Chinese researchers say they have discovered a novel H5N9 virus that represents a hybrid of the highly pathogenic H5N1 avian flu virus and a human H7N9 virus, along with other elements. The Novel H7N9 avian influenza virus (AIV), was demonstrated to cause severe human respiratory infections in China.
Evolutionary analysis showed that the hemagglutination and neuraminidase genes of the novel H5N9 virus originated from A/Muscovy duck/Vietnam/LBM227/2012 (H5N1) belonging to Clade 2.3.2.1 and human-infective A/Hangzhou/1/2013 (H7N9), six internal genes were similar to those of the H5N1, H7N9 and H9N2 viruses. The virus harbored the PQRERRRKR/GL motif characteristic of highly pathogenic AIVs at the HA cleavage site. Receptor-binding experiments demonstrated that the virus binds α-2,3 sialic acid, but not α-2,6 sialic acid. Identically, pathogenicity experiment also showed that the virus caused low mortality rates in mice. This newly isolated H5N9 virus is a highly pathogenic reassortant virus originating from H5N1, H7N9 and H9N2 subtypes. Live bird markets represent a potential transmission risk to public health and the poultry industry.