tetano
Editor, Senior Moderator
J Virol. 2016 Sep 28. pii: JVI.01457-16. [Epub ahead of print]
[h=1]Introduction, evolution, and dissemination of influenza A viruses in exhibition swine, USA, 2009-2013.[/h] Nelson MI[SUP]1[/SUP], Stucker KM[SUP]2[/SUP], Schobel SA[SUP]2[/SUP], Trov?o NS[SUP]3[/SUP], Das SR[SUP]2[/SUP], Dugan VG[SUP]2[/SUP], Nelson SW[SUP]4[/SUP], Sreevatsan S[SUP]5[/SUP], Killian ML[SUP]6[/SUP], Nolting JM[SUP]4[/SUP], Wentworth DE[SUP]2[/SUP], Bowman AS[SUP]7[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The swine-human interface created at agricultural fairs, along with the generation of and maintenance of influenza A virus diversity in exhibition swine, presents an ongoing threat to public health. Nucleotide sequences of influenza A virus isolates collected from exhibition swine in Ohio (n=262) and Indiana (n=103) during 2009-2013 were used to investigate viral evolution and movement within this niche sector of the swine industry. Phylogenetic and Bayesian analyses were employed to identify introductions of influenza A virus to exhibition swine and study viral population dynamics. In 2013 alone, we identified ten independent introductions of influenza A virus into Ohio and/or Indiana exhibition swine. Frequently, viruses from the same introduction were identified at multiple fairs within the region, providing evidence of rapid and widespread viral movement within the exhibition swine populations of the two states. While pigs moving fair-to-fair-to-fair is possible in some locations, the concurrent detection of nearly identical strains at several fairs indicates a viral common source was more likely. Importantly, we detected an association between the high number of human H3N2v infections in 2012 and the widespread circulation of influenza A viruses of the same genotype in exhibition swine in Ohio fairs sampled that year. The extent of viral diversity observed in exhibition swine, and the rapidity with which it disseminated across long distances, indicates that novel strains of influenza A virus will continue to emerge and spread within exhibition swine populations, presenting an ongoing threat to humans.
[h=4]IMPORTANCE:[/h] Understanding the underlying population dynamics of influenza A viruses in commercial and exhibition swine is central to assessing the risk for human infections with variant viruses, including H3N2v. We used viral genomic sequences from isolates collected from exhibition swine during 2009-2013 to understand how the peak of H3N2v cases in 2012 relates to long-term trends in the population dynamics of pandemic viruses recently introduced into commercial and exhibition swine in the United States. Our spatial analysis underscores the key role of rapid viral dispersal in spreading multiple genetic lineages throughout a multi-state network of agricultural fairs, providing opportunities for divergent lineages to co-infect, reassort, and generate new viral genotypes. The higher genetic diversity of genotypes co-circulating in exhibition swine since 2013 could facilitate the evolution of new reassortants, potentially with even greater ability to cause severe infections in humans or transmit human-to-human, highlighting the need for continued vigilance.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27681134 DOI: 10.1128/JVI.01457-16
[PubMed - as supplied by publisher]
[h=1]Introduction, evolution, and dissemination of influenza A viruses in exhibition swine, USA, 2009-2013.[/h] Nelson MI[SUP]1[/SUP], Stucker KM[SUP]2[/SUP], Schobel SA[SUP]2[/SUP], Trov?o NS[SUP]3[/SUP], Das SR[SUP]2[/SUP], Dugan VG[SUP]2[/SUP], Nelson SW[SUP]4[/SUP], Sreevatsan S[SUP]5[/SUP], Killian ML[SUP]6[/SUP], Nolting JM[SUP]4[/SUP], Wentworth DE[SUP]2[/SUP], Bowman AS[SUP]7[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] The swine-human interface created at agricultural fairs, along with the generation of and maintenance of influenza A virus diversity in exhibition swine, presents an ongoing threat to public health. Nucleotide sequences of influenza A virus isolates collected from exhibition swine in Ohio (n=262) and Indiana (n=103) during 2009-2013 were used to investigate viral evolution and movement within this niche sector of the swine industry. Phylogenetic and Bayesian analyses were employed to identify introductions of influenza A virus to exhibition swine and study viral population dynamics. In 2013 alone, we identified ten independent introductions of influenza A virus into Ohio and/or Indiana exhibition swine. Frequently, viruses from the same introduction were identified at multiple fairs within the region, providing evidence of rapid and widespread viral movement within the exhibition swine populations of the two states. While pigs moving fair-to-fair-to-fair is possible in some locations, the concurrent detection of nearly identical strains at several fairs indicates a viral common source was more likely. Importantly, we detected an association between the high number of human H3N2v infections in 2012 and the widespread circulation of influenza A viruses of the same genotype in exhibition swine in Ohio fairs sampled that year. The extent of viral diversity observed in exhibition swine, and the rapidity with which it disseminated across long distances, indicates that novel strains of influenza A virus will continue to emerge and spread within exhibition swine populations, presenting an ongoing threat to humans.
[h=4]IMPORTANCE:[/h] Understanding the underlying population dynamics of influenza A viruses in commercial and exhibition swine is central to assessing the risk for human infections with variant viruses, including H3N2v. We used viral genomic sequences from isolates collected from exhibition swine during 2009-2013 to understand how the peak of H3N2v cases in 2012 relates to long-term trends in the population dynamics of pandemic viruses recently introduced into commercial and exhibition swine in the United States. Our spatial analysis underscores the key role of rapid viral dispersal in spreading multiple genetic lineages throughout a multi-state network of agricultural fairs, providing opportunities for divergent lineages to co-infect, reassort, and generate new viral genotypes. The higher genetic diversity of genotypes co-circulating in exhibition swine since 2013 could facilitate the evolution of new reassortants, potentially with even greater ability to cause severe infections in humans or transmit human-to-human, highlighting the need for continued vigilance.
Copyright ? 2016, American Society for Microbiology. All Rights Reserved.
PMID: 27681134 DOI: 10.1128/JVI.01457-16
[PubMed - as supplied by publisher]