Rapid Evolution of H5N1 Influenza Viruses in Chickens in Hong Kong

摘要: The H5N1 avian influenza virus that killed 6 of 18 persons infected in Hong Kong 1997 was transmitted directly from poultry to humans. Viral isolates this outbreak may provide molecular clues zoonotic transfer. Here we demonstrate the viruses circulating comprised two distinguishable phylogenetic lineages all genes were very rapid evolution. When introduced into new hosts, usually undergo alteration their surface glycoproteins, especially hemagglutinin (HA). Surprisingly, these had a large proportion amino acid changes gene products except HA. These maybe reassortants each whose HA is well adapted domestic while rest genome arises different source. consensus sequences “internal” virion proteins reveal acids previously found human strains. human-specific be important factors transmission.