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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #183599
Title: NOVEL SWINE INFLUENZA VIRUS SUBTYPE H3N1, UNITED STATES

Author
item LEKCHAROENSUK, PORNTIPPA - KASETSART UNIV, BANGKOK
item Lager, Kelly
item VEMULAPALLI, RAMESH - PURDUE UNIVERSITY
item WOODRUFF, MARY - PURDUE UNIVERSITY
item Baker, Amy
item Richt, Juergen

Submitted to: Emerging Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/9/2006
Publication Date: 5/1/2006
Citation: Lekcharoensuk, P., Lager, K.M., Vemulapalli, R., Woodruff, M., Vincent, A.L., Richt, J.A. 2006. Novel swine influenza virus subtype H3N1, United States. Emerging Infectious Diseases. 12(5):787-794.

Interpretive Summary: Influenza A virus infects various animal species and transmits among different hosts, especially between humans and swine. Pigs may serve as a mixing vessel to create new reassortants that could infect humans. Here we report the emergence and characterization of a novel swine influenza virus (SIV) subtype in the Midwestern United States. This new H3N1 subtype acquired the hemagglutinin gene from an H3N2 turkey virus, the neuraminidase gene from a human H1N1 virus, and the remaining genes from currently circulating SIVs. Pigs inoculated with the H3N1 SIVs produced lung lesions and shed the viruses in nasal secretions. This is the first description of this new subtype of swine influenza viruses in U.S. swine. If these novel viruses continue to circulate in the U.S. swine population, the reported molecular characterization of these novel swine viruses will allow us to design better diagnostic tools and vaccination strategies.

Technical Abstract: Influenza A virus infects various animal species and transmits among different hosts, especially between humans and swine. Pigs may serve as a mixing vessel to create new reassortants that could infect humans. Thus, monitoring and characterization of influenza viruses in swine is important for the prevention of interspecies transmission. Here we report the emergence and characterization of a novel H3N1 subtype of swine influenza virus (SIV) in the United States. Phylogenetic analysis revealed that the H3N1 SIVs may have acquired the hemagglutinin gene from an H3N2 turkey virus, the neuraminase gene from a human H1N1 virus, and the remaining genes from currently circulating SIVs. The H3N1 SIVs were antigenically related to the turkey virus. Pigs inoculated with the H3N1 SIVs produced lung lesions and nasal shedding, suggesting the potential to transmit among swine and to humans. Whether this novel subtype will continue to circulate in swine population needs further surveillance.