Submitted to: Options for the Control of Influenza Conference
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2007
Publication Date: 6/18/2007
Citation: Spackman, E., Swayne, D.E., Suarez, D.L., Senne, D., Pasick, J., Handel, K., Ip, H., Slemons, R., Stallknecht, D. 2007. Genetic analysis of the H5 HA from North American wild bird origin avian influenza viruses [abstract]. Options for the Control of Influenza VI Conference, June 17-23, 2007, Toronto, Canada. p. 171.
Technical Abstract: Some strains of the current H5N1 HPAI viruses circulating in Asia have acquired the unusual ability to cause morbidity and mortality in some species of ducks. Currently little is understood about the molecular basis of this pathogenic feature, however because of the role of the HA protein in the pathogenesis of the virus in other species, evaluating the differences in HA sequence between pathogenic and non-pathogenic viruses of the same subtype may provide insight. Evaluation of LPAI viruses isolated from wild birds in North America provides one such data set for initial evaluation and may serve as an example of natural-host adapted virus. Here we present the initial genetic analysis, including the proteolytic cleavage site sequence analysis, and phylogenetic analysis of the H5 HA genes of 70 H5 viruses isolated from wild birds in North America between 1975 and 2006. Sequences from the duck-origin viruses from North America were also compared to the H5 HA from chicken adapted avian influenza viruses from Mexico and the Asian H5 HPAI HA. Numerous sublineages of H5 viruses in wild bird-origin isolates were observed. All have low pathogenic type cleavage sites and were more closely related to other North American origin viruses that to the Eurasian H5 viruses as expected.