ARS | Publication request: CHARACTERIZATION OF HIGHLY PATHOGENIC H5N1 AVIAN INFLUENZA A VIRUSES ISOLATED FROM KOREAN POULTRY

Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 13, 2004
Publication Date: March 23, 2005
Citation: Lee, C.W., Suarez, D.L., Tumpey, T.M., Sung, H., Kwon, Y., Lee, Y., Choi, J., Joh, S., Kim, M., Lee, E., Park, J., Lu, X., Katz, J.M., Spackman, E., Swayne, D.E., Kim, J. 2005. Characterization of highly pathogenic h5n1 avian influenza a viruses isolated from korean poultry. Journal of Virology. 79:3692-3702.

Interpretive Summary: An unprecedented outbreak of H5N1 highly pathogenic avian influenza (HPAI) was reported in poultry from 8 different Asian countries beginning in South Korea during December 2003. No human infections were reported with the Korean virus. Inoculation of mice with the Korean virus did not produce disease, suggesting the ability of this virus to cross from birds to humans was unlikely. However, the virus was highly lethal in chickens and quail, and caused low mortality in ducks and grew in the brains of all three bird species. The Korean virus had the hemagglutinin and neuraminidase genes from the H5N1 Guangdong/96 virus isolated from geese in China, but the internal genes had changed through reassortment with other avian influenza viruses. Our study emphasizes the need for comparative analysis of the H5N1 isolates from different countries to help elucidate the risk of a human pandemic from the strains of H5N1 HPAI currently circulating in Asia.

Technical Abstract: An unprecedented outbreak of H5N1 highly pathogenic avian influenza (HPAI) was reported in poultry from 8 different Asian countries since December 2003. This AI virus also had a zoonotic component with at least 23 fatal cases in Vietnam and Thailand. The first official report of H5N1 AI in Asia was made from South Korea and it was the first HPAI outbreak in Korea's history. Phylogenetic analysis of the 8 viral genes showed that the H5N1 viruses isolated from Korean poultry were of avian origin and contained the HA and NA genes of A/goose/Guangdong/1/96 (Gs/Gd) lineage. The current H5N1 strains in Asia, including the Korean isolates, shared a gene constellation that was similar to the Penfold Park, Hong Kong isolates from late 2002 and contained some molecular markers that seemed to be fixed in the Gs/Gd lineage virus since 2001. However, despite genetic similarities among recent H5N1 isolates, the topology of the phylogenetic tree clearly differentiated the Korean isolates from the Vietnamese and Thai isolates where human infections were reported. One of the Korean isolates was inoculated into mice and found to be non-pathogenic. The isolate, however, was highly lethal in chickens and quail, and caused some mortality in ducks and replicated in the brains of all three avian species. Our study characterizes the molecular and biological properties of the Korean H5N1 HPAI viruses and emphasizes the need for comparative analysis of the H5N1 isolates from different countries to help elucidate the risk of a human pandemic from the strains of H5N1 HPAI currently circulating in Asia.