scholarly journals Feral Swine in the United States Have Been Exposed to both Avian and Swine Influenza A Viruses

2017 ◽  
Vol 83 (19) ◽  
Author(s):  
Brigitte E. Martin ◽  
Hailiang Sun ◽  
Margaret Carrel ◽  
Fred L. Cunningham ◽  
John A. Baroch ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
Swine Influenza ◽  
The United States ◽  
Wild Birds ◽  
Influenza A Viruses ◽  
Serum Samples ◽  
Feral Swine ◽  
Free Ranging ◽  
Domestic Swine

ABSTRACT Influenza A viruses (IAVs) in swine can cause sporadic infections and pandemic outbreaks among humans, but how avian IAV emerges in swine is still unclear. Unlike domestic swine, feral swine are free ranging and have many opportunities for IAV exposure through contacts with various habitats and animals, including migratory waterfowl, a natural reservoir for IAVs. During the period from 2010 to 2013, 8,239 serum samples were collected from feral swine across 35 U.S. states and tested against 45 contemporary antigenic variants of avian, swine, and human IAVs; of these, 406 (4.9%) samples were IAV antibody positive. Among 294 serum samples selected for antigenic characterization, 271 cross-reacted with ≥1 tested virus, whereas the other 23 did not cross-react with any tested virus. Of the 271 IAV-positive samples, 236 cross-reacted with swine IAVs, 1 with avian IAVs, and 16 with avian and swine IAVs, indicating that feral swine had been exposed to both swine and avian IAVs but predominantly to swine IAVs. Our findings suggest that feral swine could potentially be infected with both avian and swine IAVs, generating novel IAVs by hosting and reassorting IAVs from wild birds and domestic swine and facilitating adaptation of avian IAVs to other hosts, including humans, before their spillover. Continued surveillance to monitor the distribution and antigenic diversities of IAVs in feral swine is necessary to increase our understanding of the natural history of IAVs. IMPORTANCE There are more than 5 million feral swine distributed across at least 35 states in the United States. In contrast to domestic swine, feral swine are free ranging and have unique opportunities for contact with wildlife, livestock, and their habitats. Our serological results indicate that feral swine in the United States have been exposed to influenza A viruses (IAVs) consistent with those found in both domestic swine and wild birds, with the predominant infections consisting of swine-adapted IAVs. Our findings suggest that feral swine have been infected with IAVs at low levels and could serve as hosts for the generation of novel IAVs at the interface of feral swine, wild birds, domestic swine, and humans.

scholarly journals Gaps in Serologic Immunity against Contemporary Swine-Origin Influenza A Viruses among Healthy Individuals in the United States

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 127
Author(s):  
Joshua N. Lorbach ◽  
Theresa Fitzgerald ◽  
Carolyn Nolan ◽  
Jacqueline M. Nolting ◽  
John J. Treanor ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
Disease Outbreaks ◽  
The United States ◽  
Influenza A Viruses ◽  
Serum Samples ◽  
Healthy Human ◽  
Human Immunity ◽  
H3 Subtype ◽  
Domestic Swine

Influenza A Viruses (IAV) in domestic swine (IAV-S) are associated with sporadic zoonotic transmission at the human–animal interface. Previous pandemic IAVs originated from animals, which emphasizes the importance of characterizing human immunity against the increasingly diverse IAV-S. We analyzed serum samples from healthy human donors (n = 153) using hemagglutination-inhibition (HAI) assay to assess existing serologic protection against a panel of contemporary IAV-S isolated from swine in the United States (n = 11). Age-specific seroprotection rates (SPR), which are the proportion of individuals with HAI ≥ 1:40, corresponded with lower or moderate pandemic risk classifications for the multiple IAV-S examined (one H1-δ1, one H1-δ2, three H3-IVA, one H3-IVB, one H3-IVF). Individuals born between 2004 and 2013 had SPRs of 0% for the five classified H3 subtype IAV-S, indicating youth may be particularly predisposed to infection with these viruses. Expansion of existing immunologic gaps over time could increase likelihood of future IAV-S spillover to humans and facilitate subsequent sustained human-to-human transmission resulting in disease outbreaks with pandemic potential.

scholarly journals Population dynamics of cocirculating swine influenza A viruses in the United States from 2009 to 2012

2013 ◽  
Vol 7 ◽  
pp. 42-51 ◽  
Author(s):  
Tavis K. Anderson ◽  
Martha I. Nelson ◽  
Pravina Kitikoon ◽  
Sabrina L. Swenson ◽  
John A. Korslund ◽  
...  
Keyword(s):  
United States ◽  
Population Dynamics ◽  
Influenza A ◽  
Swine Influenza ◽  
The United States ◽  
Influenza A Viruses

scholarly journals Genetic Evidence Supports Sporadic and Independent Introductions of Subtype H5 Low-Pathogenic Avian Influenza A Viruses from Wild Birds to Domestic Poultry in North America

2018 ◽  
Vol 92 (19) ◽  
Author(s):  
Lei Li ◽  
Andrew S. Bowman ◽  
Thomas J. DeLiberto ◽  
Mary L. Killian ◽  
Scott Krauss ◽  
...  
Keyword(s):  
United States ◽  
Avian Influenza ◽  
Influenza A ◽  
The United States ◽  
Wild Birds ◽  
Influenza A Viruses ◽  
Pathogenic Avian Influenza ◽  
Live Bird Markets ◽  
Domestic Poultry ◽  
Live Bird

ABSTRACTWild-bird origin influenza A viruses (IAVs or avian influenza) have led to sporadic outbreaks among domestic poultry in the United States and Canada, resulting in economic losses through the implementation of costly containment practices and destruction of birds. We used evolutionary analyses of virus sequence data to determine that 78 H5 low-pathogenic avian influenza viruses (LPAIVs) isolated from domestic poultry in the United States and Canada during 2001 to 2017 resulted from 18 independent virus introductions from wild birds. Within the wild-bird reservoir, the hemagglutinin gene segments of H5 LPAIVs exist primarily as two cocirculating genetic sublineages, and our findings suggest that the H5 gene segments flow within each migratory bird flyway and among adjacent flyways, with limited exchange between the nonadjacent Atlantic and Pacific Flyways. Phylogeographic analyses provided evidence that IAVs from dabbling ducks and swans/geese contributed to the emergence of viruses among domestic poultry. H5 LPAIVs isolated from commercial farm poultry (i.e., turkey) that were descended from a single introduction typically remained a single genotype, whereas those from live-bird markets sometimes led to multiple genotypes, reflecting the potential for reassortment with other IAVs circulating within live-bird markets. H5 LPAIVs introduced from wild birds to domestic poultry represent economic threats to the U.S. poultry industry, and our data suggest that such introductions have been sporadic, controlled effectively through production monitoring and a stamping-out policy, and are, therefore, unlikely to result in sustained detections in commercial poultry operations.IMPORTANCEIntegration of viral genome sequencing into influenza surveillance for wild birds and domestic poultry can elucidate evolutionary pathways of economically costly poultry pathogens. Evolutionary analyses of H5 LPAIVs detected in domestic poultry in the United States and Canada during 2001 to 2017 suggest that these viruses originated from repeated introductions of IAVs from wild birds, followed by various degrees of reassortment. Reassortment was observed where biosecurity was low and where opportunities for more than one virus to circulate existed (e.g., congregations of birds from different premises, such as live-bird markets). None of the H5 lineages identified were maintained for the long term in domestic poultry, suggesting that management strategies have been effective in minimizing the impacts of virus introductions on U.S. poultry production.

Evolution and antigenic advancement of N2 neuraminidase of swine influenza A viruses circulating in the United States following two separate introductions from human seasonal viruses

2021 ◽  
Author(s):  
Bryan S. Kaplan ◽  
Tavis K. Anderson ◽  
Jennifer Chang ◽  
Jefferson Santos ◽  
Daniel Perez ◽  
...  
Keyword(s):  
United States ◽  
Influenza A Virus ◽  
Influenza A ◽  
Vaccine Development ◽  
Swine Influenza ◽  
The United States ◽  
Antigenic Drift ◽  
Effective Control ◽  
Influenza A Viruses ◽  
Antigenic Diversity

Two separate introductions of human seasonal N2 neuraminidase genes were sustained in United States swine since 1998 (N2-98) and 2002 (N2-02). Herein, we characterized the antigenic evolution of the N2 of swine influenza A virus (IAV) across two decades following each introduction. The N2-98 and N2-02 expanded in genetic diversity, with two statistically supported monophyletic clades within each lineage. To assess antigenic drift in swine N2 following the human-to-swine spillover events, we generated a panel of swine N2 antisera against representative N2 and quantified the antigenic distance between wild-type viruses using enzyme-linked lectin assay and antigenic cartography. The antigenic distance between swine and human N2 was smallest between human N2 circulating at the time of each introduction and the archetypal swine N2. However, sustained circulation and evolution in swine of the two N2 lineages resulted in significant antigenic drift, and the N2-98 and N2-02 swine N2 lineages were antigenically distinct. Although intra-lineage antigenic diversity was observed, the magnitude of antigenic drift did not consistently correlate with the observed genetic differences. These data represent the first quantification of the antigenic diversity of neuraminidase of IAV in swine and demonstrated significant antigenic drift from contemporary human seasonal strains as well as antigenic variation among N2 detected in swine. These data suggest that antigenic mismatch may occur between circulating swine IAV and vaccine strains. Consequently, consideration of the diversity of N2 in swine IAV for vaccine selection may likely result in more effective control, and aid public health initiatives for pandemic preparedness. Importance Antibodies inhibiting the neuraminidase (NA) of influenza A virus (IAV) reduce clinical disease, virus shedding, and transmission, particularly in the absence of neutralizing immunity against the hemagglutinin. To understand antibody recognition of the genetically diverse NA in U.S. swine IAV, we characterized the antigenic diversity of N2 from swine and humans. N2 detected in swine IAV were derived from two distinct human-to-swine spillovers that persisted, are antigenically distinct, and underwent antigenic drift. These findings highlight the need for continued surveillance and vaccine development in swine with increased focus on the NA. Additionally, human seasonal N2 isolated after 2005 were poorly inhibited by representative swine N2 antisera, suggesting a lack of cross-reactive NA antibody mediated immunity between contemporary swine and human N2. Bidirectional transmission between humans and swine represents a One Health challenge, and determining the correlates of immunity to emerging IAV strains is critical to mitigate zoonotic and reverse-zoonotic transmission.

scholarly journals Antigenic evolution of H3N2 influenza A viruses in swine in the United States from 2012 to 2016

2018 ◽  
Vol 13 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Marcus J. Bolton ◽  
Eugenio J. Abente ◽  
Divya Venkatesh ◽  
Jered A. Stratton ◽  
Michael Zeller ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
The United States ◽  
Influenza A Viruses ◽  
Antigenic Evolution ◽  
H3n2 Influenza

scholarly journals Introduction, Evolution, and Dissemination of Influenza A Viruses in Exhibition Swine in the United States during 2009 to 2013

2016 ◽  
Vol 90 (23) ◽  
pp. 10963-10971 ◽  
Author(s):  
Martha I. Nelson ◽  
Karla M. Stucker ◽  
Seth A. Schobel ◽  
Nídia S. Trovão ◽  
Suman R. Das ◽  
...  
Keyword(s):  
United States ◽  
Population Dynamics ◽  
Influenza A Virus ◽  
Influenza A ◽  
The United States ◽  
Viral Population ◽  
Influenza A Viruses ◽  
Swine Industry ◽  
Virus Diversity ◽  
Agricultural Fairs

ABSTRACT 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 to 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 10 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 from fair to fair to fair is possible in some locations, the concurrent detection of nearly identical strains at several fairs indicates that a common viral source was more likely. Importantly, we detected an association between the high number of human variant H3N2 (H3N2v) virus 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 indicate that novel strains of influenza A virus will continue to emerge and spread within exhibition swine populations, presenting an ongoing threat to humans. IMPORTANCE 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 to 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. The results of our spatial analysis underscore the key role of rapid viral dispersal in spreading multiple genetic lineages throughout a multistate network of agricultural fairs, providing opportunities for divergent lineages to coinfect, reassort, and generate new viral genotypes. The higher genetic diversity of genotypes cocirculating in exhibition swine since 2013 could facilitate the evolution of new reassortants, potentially with even greater ability to cause severe infections in humans or cause human-to-human transmission, highlighting the need for continued vigilance.

Interspecies Transmission and Reassortment of Influenza A Viruses in Pigs and Turkeys in the United States

1992 ◽  
Vol 136 (4) ◽  
pp. 488-497 ◽  
Author(s):  
Stephen M. Wright ◽  
Yoshihiro Kawaoka ◽  
Gerold B. Sharp ◽  
Dennis A. Senne ◽  
Robert G. Webster
Keyword(s):  
United States ◽  
Influenza A ◽  
The United States ◽  
Interspecies Transmission ◽  
Influenza A Viruses

scholarly journals Genetic Characterization of H1N2 Influenza A Viruses Isolated from Pigs throughout the United States

2002 ◽  
Vol 40 (3) ◽  
pp. 1073-1079 ◽  
Author(s):  
A. I. Karasin ◽  
J. Landgraf ◽  
S. Swenson ◽  
G. Erickson ◽  
S. Goyal ◽  
...  
Keyword(s):  
United States ◽  
Influenza A ◽  
Genetic Characterization ◽  
The United States ◽  
Influenza A Viruses

scholarly journals The enigma of the apparent disappearance of Eurasian highly pathogenic H5 clade 2.3.4.4 influenza A viruses in North American waterfowl

2016 ◽  
Vol 113 (32) ◽  
pp. 9033-9038 ◽  
Author(s):  
Scott Krauss ◽  
David E. Stallknecht ◽  
Richard D. Slemons ◽  
Andrew S. Bowman ◽  
Rebecca L. Poulson ◽  
...  
Keyword(s):  
United States ◽  
North America ◽  
North American ◽  
Influenza A ◽  
Wild Bird ◽  
Animal Health ◽  
The United States ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Highly Pathogenic

One of the major unresolved questions in influenza A virus (IAV) ecology is exemplified by the apparent disappearance of highly pathogenic (HP) H5N1, H5N2, and H5N8 (H5Nx) viruses containing the Eurasian hemagglutinin 2.3.4.4 clade from wild bird populations in North America. The introduction of Eurasian lineage HP H5 clade 2.3.4.4 H5N8 IAV and subsequent reassortment with low-pathogenic H?N2 and H?N1 North American wild bird-origin IAVs in late 2014 resulted in widespread HP H5Nx IAV infections and outbreaks in poultry and wild birds across two-thirds of North America starting in November 2014 and continuing through June 2015. Although the stamping out strategies adopted by the poultry industry and animal health authorities in Canada and the United States—which included culling, quarantining, increased biosecurity, and abstention from vaccine use—were successful in eradicating the HP H5Nx viruses from poultry, these activities do not explain the apparent disappearance of these viruses from migratory waterfowl. Here we examine current and historical aquatic bird IAV surveillance and outbreaks of HP H5Nx in poultry in the United States and Canada, providing additional evidence of unresolved mechanisms that restrict the emergence and perpetuation of HP avian influenza viruses in these natural reservoirs.

Sign in / Sign up

Export Citation Format

Share Document