Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/14/2002
Publication Date: 9/1/2003
Citation: Tumpey, T., Suarez, D.L., Perkins, L.E., Senne, D.A., Lee, J., Lee, Y., Mo, I., Sung, H., Swayne, D.E., Evaluation Of A Highly Pathogenic H5N1 Avian Influenza A Virus Isolated From Duck Meat. Avian Diseases, 47:951-955, 2003. Interpretive Summary: The influenza (H5N1) outbreak in 1997 in Hong Kong created a new awareness that avian influenza viruses could spread directly from poultry to humans and cause severe disease in humans. Although no influenza H5N1 viruses have been isolated from humans since December 1997, recent virological surveillance has indicated that similar viruses can be still be isolated from poultry in Southeastern China. In April 2001, an avian H5N1 influenza A virus was isolated from duck meat that had been imported from China to Korea. We investigated the molecular characterization and pathogenesis of this recent H5N1 virus isolated from duck meat. Like the Hong Kong H5N1 viruses, this virus was lethal for chickens and induced some mortality in mice. No mortality was observed in experimental ducks, but relatively high levels of infectious virus was detected in duck skeletal muscle and brain tissue isolated shortly after infection. To our knowledge, this is the first demonstration of a H5N1 influenza virus isolated from duck meat and raises important health implications.
Technical Abstract: The introduction of an influenza A virus possessing a novel hemagglutinin (HA) into an immunologically naive human population has the potential to cause severe disease and death. Such was the case in 1997 in Hong Kong, where H5N1 influenza was transmitted to humans from infected poultry. Because H5N1 viruses are still isolated from domestic poultry in southern China, there needs to be continued surveillance of poultry and characterization of virus subtypes and variants. This study provides a molecular characterization and evaluation of pathogenesis of a recent H5N1 virus isolated from duck meat that had been imported to South Korea from China. The HA gene of A/Duck/Anyang/AVL-1/01 isolate was found to be closely related to the Hong Kong/97 H5N1 viruses. This virus also contained multiple basic amino acids adjacent to the cleavage site between HA1 and HA2, characteristic of highly pathogenic avian influenza viruses (HPAI). The pathogenesis of this virus was characterized in chickens, ducks, and mice. The DK/Anyang/AVL-1/01 isolate replicated well in all species and resulted in 100% and 22% lethality for chickens and mice, respectively. No clinical signs of disease were observed in DK/Anyang/AVL-1/01-inoculated ducks, but high titers of infectious virus could be detected in multiple tissues and oropharyngeal swabs. The presence of an H5N1 influenza virus in ducks bearing a HA gene that is highly similar to those of the pathogenic 1997 human/poultry H5N1 viruses, raises the possibility of reintroduction of HPAI to chickens and humans.