Submitted to: Southeastern Regional Virology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 4/12/2002
Publication Date: 4/12/2002
Citation: Spackman, E., Suarez, D.L. 2002. Phylogenetic Analysis Of The Influenza H7 Hemagglutinin Gene And HA1 Protein From Viruses Isolated From U.S. Live Bird Markets In The Northeast. Southeastern Regional Virology Conference.
Technical Abstract: Avian influenza viruses (AIV) with the H7 hemagglutinin (HA) subtype have been circulating in the urban live-bird market (LBM) system in the Northeastern U.S. since approximately 1994 and are a concern for the poultry industry. In order to evaluate the potential for the virus to become highly pathogenic and to better understand the evolution and epidemiology of the virus within the LBM's, we have performed sequence and phylogenetic analysis of the HA gene and HA protein from AIV's isolated from the LBM's between 1994 and 2001. Phylogenetic analysis of the HA gene shows a strong chronological association among the isolates and is consistent with a single primary introduction of an H7 subtype virus into the LBM's. Sequence analysis of the HA protein cleavage site, which is strongly correlated with pathogenicity in poultry, revealed three progressive amino acid changes since 1999, two of which were substitutions for basic amino acids in sites which previously contained non-basic amino acids. These changes increase the concern that highly pathogenic AIV could emerge from this lineage.