Submitted to: American Veterinary Medical Association Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 22, 2010
Publication Date: July 31, 2010
Citation: Vincent, A.L. 2010. Zoonoses: USDA ARS Lessons Learned During Novel Influenza H1N1 Investigations [abstract]. American Veterinary Medical Association 147th Annual Convention. Paper No. 8515. Technical Abstract: Influenza illness was first recognized in pigs during the 1918 human Spanish flu pandemic, and influenza A virus has since remained of importance to the swine industry as a primary respiratory pathogen. Influenza virus H1N1 remained relatively stable in U.S. swine for nearly 80 years following 1918, whereas multiple subtypes and genotypes have emerged since 1998. Contemporary North American “triple reassortant” lineage viruses have a conserved constellation of 6 genes from avian, human, and swine virus lineages, excluding the surface glycoproteins (HA and NA). Since 1998, HA and NA from human seasonal H3N2 and H1N1 have been introduced to the U.S. swine population, representing “reverse zoonotic” events. Likewise, sporadic cases of human infection with contemporary triple reassortant swine viruses were documented between 2005 and 2009. The gene constellation of the 2009 pandemic H1N1 virus is a combination of genes from swine viruses of North American and Eurasian lineages, but prior to April 2009 had never been identified in swine or other species. Numerous cases of swine infections with 2009 H1N1 have since been documented around the world, including the U.S., and were thought to be primarily associated with ill farm workers. With the number of subtypes and genetic variants of influenza virus circulating in swine and other host species, a better understanding of all animal influenza viruses has become increasingly important. The influenza research program at USDA-ARS NADC in collaboration with USDA-APHIS and CDC partners leading up to and following the 2009 pandemic will be discussed.