In late summer through early winter of 1998, there were several outbreaks of respiratory disease in the swine herds of North Carolina, Texas, Minnesota and Iowa. Four viral isolates from outbreaks in different states were analyzed, both antigenically and genetically. All of the isolates were identified as H3N2 influenza viruses with antigenic profiles similar to those of recent human H3 strains. Genotyping and phylogenetic analysis demonstrated that the four swine viruses had emerged through two different pathways. The North Carolina isolate is the product of genetic reassortment between human and swine influenza viruses, while the others arose from reassortment of human, swine and avian viral genes. The hemagglutinin genes of the four isolates were all derived from the human H3N2 virus circulating in 1995. It remains to be determined if either of these recently emerged viruses will become established in the pigs in North America and whether they will become an economic burden. Copyright (C) 2000 Elsevier Science B.V.
|Original language||English (US)|
|Number of pages||12|
|State||Published - May 22 2000|
Bibliographical noteFunding Information:
We thank Gary Walch of USDA, TX, for field investigation and providing the virus from Texas, Melissa Norwood, David Walker and Lijuan Zhang for excellent technical assistance. These studies were supported by Public Health Service Grants AI29680, AI95357 and Cancer Center Support (CORE) Grant CA-21765 from the National Institute of Health, and by the American Lebanese Syrian Associated Charities. We thank Alice Herren for manuscript preparation.
Copyright 2007 Elsevier B.V., All rights reserved.
- Influenza viruses