Molecular and antigenic characterization of triple-reassortant H3N2 swine influenza viruses isolated from pigs, turkey and quail in Canada.

In 2005, triple-reassortant H3N2 (trH3N2) influenza A viruses were isolated from swine and turkeys in Canada. Subsequently, these viruses were isolated from humans and mink in 2006 and 2007, respectively. Following full genome sequencing, H3N2 viruses isolated from turkeys (2005), quail (2008) and swine (2009) in Canada, were characterized as trH3N2. The 2005 turkey isolate was found to be almost identical to other viruses isolated in that year, with quail and pig isolates related very closely to the 2005 trH3N2. Minimal antigenic evolution of the swine isolates relative to the reference 2005 virus was observed. These results suggest the establishment of a stable lineage of trH3N2 in Canadian pigs, with evidence for interspecies transmission to turkeys and quails.