Evaluate swine influenza virus (SIV) isolates through in vivo challenge and transmission studies, antigenic characterization with in-house reference sera, and molecular analysis.
APPROACH: The ARS' National Animal Disease Center (NADC) will support the proposed USDA-APHIS swine influenza surveillance program by providing additional characterization of emerging swine influenza virus (SIV) isolates identified through the surveillance program. The SIV isolates will be evaluated through in vivo challenge and transmission studies, antigenic characterization with in-house reference sera, and molecular analysis. Molecular analysis may include follow-up sequencing, nucleic acid and amino acid sequence comparisons, as well as computation of evolutionary relationships with reference sequences to construct phylogenetic trees. The in vivo studies will aid in identifying viruses with increased virulence, increased transmissibility, or other phenotypic properties. The molecular analyses will aid in identifying viruses with novel genetic make-up and allow a better understanding of the evolution and epidemiology of whole virus genomes. In addition to the NALN submission criteria, the NADC criteria shall be 1) Novel subtype; 2) Novel gene introduction; 3) Novel antigenic properties; or 4) Unusual clinical presentation.