Progress on Origin and Evolvement Of Avian influenza virus H5N1 Subtype

In this article the author reviewed the origin and evolvement of the avian influenza virus(H5N1).The evidence indicated that A / Hongkong / 97(H5N1)of avian influenza virus and the current epidemic trains which could infect humans originated possibly the avian influenza virus(A/Goose/Guangdong/1/96).From 1996 onwards,fifteen H5N1 genotypes(Gs/Gd,A,B,C,D,E,V,W,X_0-X_3,Y,Z,Z~+) were detected.The genotype Z replaced others to become dominant at present.Highly pathogenic avian influenza virus(HPAIV) involving at least three subtypes,H5,H7 and H9,can obtain the abilities of bi-directional transmission between terrestrial and aquatic poultry by gene reassortants,which could be widely spread by the migration birds in the world and are not easily eradicable.These developments pose a threat to public and poultry health in the region and potentially the world,and suggest that long-term control measures are required.