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VanInsberghe D, McBride DS, DaSilva J, Stark TJ, Lau MSY, Shepard SS, Barnes JR, Bowman AS, Lowen AC, Koelle K. Genetic drift and purifying selection shape within-host influenza A virus populations during natural swine infections. PLoS Pathog 2024; 20:e1012131. [PMID: 38626244 PMCID: PMC11051653 DOI: 10.1371/journal.ppat.1012131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 04/26/2024] [Accepted: 03/16/2024] [Indexed: 04/18/2024] Open
Abstract
Patterns of within-host influenza A virus (IAV) diversity and evolution have been described in natural human infections, but these patterns remain poorly characterized in non-human hosts. Elucidating these dynamics is important to better understand IAV biology and the evolutionary processes that govern spillover into humans. Here, we sampled an IAV outbreak in pigs during a week-long county fair to characterize viral diversity and evolution in this important reservoir host. Nasal wipes were collected on a daily basis from all pigs present at the fair, yielding up to 421 samples per day. Subtyping of PCR-positive samples revealed the co-circulation of H1N1 and H3N2 subtype swine IAVs. PCR-positive samples with robust Ct values were deep-sequenced, yielding 506 sequenced samples from a total of 253 pigs. Based on higher-depth re-sequenced data from a subset of these initially sequenced samples (260 samples from 168 pigs), we characterized patterns of within-host IAV genetic diversity and evolution. We find that IAV genetic diversity in single-subtype infected pigs is low, with the majority of intrahost Single Nucleotide Variants (iSNVs) present at frequencies of <10%. The ratio of the number of nonsynonymous to the number of synonymous iSNVs is significantly lower than under the neutral expectation, indicating that purifying selection shapes patterns of within-host viral diversity in swine. The dynamic turnover of iSNVs and their pronounced frequency changes further indicate that genetic drift also plays an important role in shaping IAV populations within pigs. Taken together, our results highlight similarities in patterns of IAV genetic diversity and evolution between humans and swine, including the role of stochastic processes in shaping within-host IAV dynamics.
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Affiliation(s)
- David VanInsberghe
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, United States of America
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
| | - Dillon S. McBride
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Juliana DaSilva
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Thomas J. Stark
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Max S. Y. Lau
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Samuel S. Shepard
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - John R. Barnes
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Andrew S. Bowman
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Anice C. Lowen
- Department of Microbiology and Immunology, Emory University, Atlanta, Georgia, United States of America
- Emory Center of Excellence for Influenza Research and Response (Emory-CEIRR), Atlanta, Georgia, United States of America
| | - Katia Koelle
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
- Emory Center of Excellence for Influenza Research and Response (Emory-CEIRR), Atlanta, Georgia, United States of America
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Kok CR, Mulakken N, Thissen JB, Grey SF, Avila-Herrera A, Upadhyay MM, Lisboa FA, Mabery S, Elster EA, Schobel SA, Be NA. Targeted metagenomic assessment reflects critical colonization in battlefield injuries. Microbiol Spectr 2023; 11:e0252023. [PMID: 37874143 PMCID: PMC10714869 DOI: 10.1128/spectrum.02520-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 09/18/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Microbial contamination in combat wounds can lead to opportunistic infections and adverse outcomes. However, current microbiological detection has a limited ability to capture microbial functional genes. This work describes the application of targeted metagenomic sequencing to profile wound bioburden and capture relevant wound-associated signatures for clinical utility. Ultimately, the ability to detect such signatures will help guide clinical decisions regarding wound care and management and aid in the prediction of wound outcomes.
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Affiliation(s)
- Car Reen Kok
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Nisha Mulakken
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - James B. Thissen
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Scott F. Grey
- Surgical Critical Care Initiative (SC2i), Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
| | - Aram Avila-Herrera
- Computing Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Meenu M. Upadhyay
- Surgical Critical Care Initiative (SC2i), Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
| | - Felipe A. Lisboa
- Surgical Critical Care Initiative (SC2i), Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
- Walter Reed National Military Medical Center, Bethesda, Maryland, USA
| | - Shalini Mabery
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
| | - Eric A. Elster
- Surgical Critical Care Initiative (SC2i), Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Walter Reed National Military Medical Center, Bethesda, Maryland, USA
| | - Seth A. Schobel
- Surgical Critical Care Initiative (SC2i), Uniformed Services University of the Health Sciences (USUHS), Bethesda, Maryland, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., Bethesda, Maryland, USA
| | - Nicholas A. Be
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, USA
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3
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VanInsberghe D, McBride DS, DaSilva J, Stark TJ, Lau MS, Shepard SS, Barnes JR, Bowman AS, Lowen AC, Koelle K. Genetic drift and purifying selection shape within-host influenza A virus populations during natural swine infections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.23.563581. [PMID: 37961583 PMCID: PMC10634741 DOI: 10.1101/2023.10.23.563581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Patterns of within-host influenza A virus (IAV) diversity and evolution have been described in natural human infections, but these patterns remain poorly characterized in non-human hosts. Elucidating these dynamics is important to better understand IAV biology and the evolutionary processes that govern spillover into humans. Here, we sampled an IAV outbreak in pigs during a week-long county fair to characterize viral diversity and evolution in this important reservoir host. Nasal wipes were collected on a daily basis from all pigs present at the fair, yielding up to 421 samples per day. Subtyping of PCR-positive samples revealed the co-circulation of H1N1 and H3N2 subtype IAVs. PCR-positive samples with robust Ct values were deep-sequenced, yielding 506 sequenced samples from a total of 253 pigs. Based on higher-depth re-sequenced data from a subset of these initially sequenced samples (260 samples from 168 pigs), we characterized patterns of within-host IAV genetic diversity and evolution. We find that IAV genetic diversity in single-subtype infected pigs is low, with the majority of intra-host single nucleotide variants (iSNVs) present at frequencies of <10%. The ratio of the number of nonsynonymous to the number of synonymous iSNVs is significantly lower than under the neutral expectation, indicating that purifying selection shapes patterns of within-host viral diversity in swine. The dynamic turnover of iSNVs and their pronounced frequency changes further indicate that genetic drift also plays an important role in shaping IAV populations within pigs. Taken together, our results highlight similarities in patterns of IAV genetic diversity and evolution between humans and swine, including the role of stochastic processes in shaping within-host IAV dynamics.
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Affiliation(s)
- David VanInsberghe
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, 30322
- Department of Biology, Emory University, Atlanta, GA, 30322
| | - Dillon S. McBride
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH 43210
| | - Juliana DaSilva
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA
| | - Thomas J. Stark
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA
| | - Max S.Y. Lau
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA, 30322
| | - Samuel S. Shepard
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA
| | - John R. Barnes
- Influenza Division, Centers for Disease Control and Prevention, Atlanta, GA
| | - Andrew S. Bowman
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, OH 43210
| | - Anice C. Lowen
- Department of Microbiology and Immunology, Emory University, Atlanta, GA, 30322
- Emory Center of Excellence for Influenza Research and Response (Emory-CEIRR)
| | - Katia Koelle
- Department of Biology, Emory University, Atlanta, GA, 30322
- Emory Center of Excellence for Influenza Research and Response (Emory-CEIRR)
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Ma W, Loving CL, Driver JP. From Snoot to Tail: A Brief Review of Influenza Virus Infection and Immunity in Pigs. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2023; 211:1187-1194. [PMID: 37782856 PMCID: PMC10824604 DOI: 10.4049/jimmunol.2300385] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/07/2023] [Indexed: 10/04/2023]
Abstract
Pigs play an important role in influenza A virus (IAV) epidemiology because they support replication of human, avian, and swine origin viruses and act as an IAV reservoir for pigs and other species, including humans. Moreover, novel IAVs with human pandemic potential may be generated in pigs. To minimize the threat of IAVs to human and swine health, it is crucial to understand host defense mechanisms that restrict viral replication and pathology in pigs. In this article, we review IAV strains circulating in the North American swine population, as well as porcine innate and acquired immune responses to IAV, including recent advances achieved through immunological tools developed specifically for swine. Furthermore, we highlight unique aspects of the porcine pulmonary immune system, which warrant consideration when developing vaccines and therapeutics to limit IAV in swine or when using pigs to model human IAV infections.
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Affiliation(s)
- Wenjun Ma
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
- Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO
| | - Crystal L. Loving
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, IA
| | - John P. Driver
- Division of Animal Sciences, University of Missouri, Columbia, MO
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5
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Griffin EF, Tompkins SM. Fitness Determinants of Influenza A Viruses. Viruses 2023; 15:1959. [PMID: 37766365 PMCID: PMC10535923 DOI: 10.3390/v15091959] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
Influenza A (IAV) is a major human respiratory pathogen that causes illness, hospitalizations, and mortality annually worldwide. IAV is also a zoonotic pathogen with a multitude of hosts, allowing for interspecies transmission, reassortment events, and the emergence of novel pandemics, as was seen in 2009 with the emergence of a swine-origin H1N1 (pdmH1N1) virus into humans, causing the first influenza pandemic of the 21st century. While the 2009 pandemic was considered to have high morbidity and low mortality, studies have linked the pdmH1N1 virus and its gene segments to increased disease in humans and animal models. Genetic components of the pdmH1N1 virus currently circulate in the swine population, reassorting with endemic swine viruses that co-circulate and occasionally spillover into humans. This is evidenced by the regular detection of variant swine IAVs in humans associated with state fairs and other intersections of humans and swine. Defining genetic changes that support species adaptation, virulence, and cross-species transmission, as well as mutations that enhance or attenuate these features, will improve our understanding of influenza biology. It aids in surveillance and virus risk assessment and guides the establishment of counter measures for emerging viruses. Here, we review the current understanding of the determinants of specific IAV phenotypes, focusing on the fitness, transmission, and virulence determinants that have been identified in swine IAVs and/or in relation to the 2009 pdmH1N1 virus.
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Affiliation(s)
- Emily Fate Griffin
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Emory-UGA Centers of Excellence for Influenza Research and Surveillance (CEIRS), Athens, GA 30602, USA
| | - Stephen Mark Tompkins
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Emory-UGA Centers of Excellence for Influenza Research and Surveillance (CEIRS), Athens, GA 30602, USA
- Center for Influenza Disease and Emergence Response (CIDER), Athens, GA 30602, USA
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Chen X, Wang W, Qin Y, Zou J, Yu H. Global epidemiology of human infections with variant influenza viruses, 1959-2021: A descriptive study. Clin Infect Dis 2022; 75:1315-1323. [PMID: 35231106 DOI: 10.1093/cid/ciac168] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Although human case numbers of variant influenza viruses have increased worldwide, the epidemiology of human cases and human-to-human transmissibility of different variant viruses remain uncertain. METHODS We used descriptive statistics to summarize the epidemiologic characteristics of variant virus infections. The hospitalization rate, case-fatality and hospitalization-fatality risks were used to assess disease severity. Transmissibility of variant viruses between humans was determined by the effective reproductive number (Re) and probability of infection following exposure to human cases. RESULTS We identified 707 cases of variant viruses from 1959-2021, and their spatiotemporal/demographic characteristics changed across subtypes. The clinical severity of cases of variant viruses was generally mild; cases older than 18 years with underlying conditions were associated with hospitalization. Of 69 clusters of human infections with variant viruses (median cluster size: 2), the upper limit of Re was 0.09 (H1N1v, H1N2v and H3N2v: 0.20 vs. 0.18 vs. 0.05), while it was not significantly different from the pooled estimates for avian influenza A(H7N9) and A(H5N1) viruses (0.10). Moreover, contacts of H5N1 cases (15.7%) had a significantly higher probability of infection than contacts of individuals with H7N9 (4.2%) and variant virus infections (4.2-7.2%). CONCLUSIONS The epidemiology of cases of variant viruses varied across time periods, geographical regions and subtypes during 1959-2021. The transmissibility of different variant viruses between humans remains limited. However, given the continuous evolution of viruses and the rapidly evolving epidemiology of cases of variant viruses, improving the surveillance systems for human variant virus infections is needed worldwide.
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Affiliation(s)
- Xinghui Chen
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Wei Wang
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Ying Qin
- Division of Infectious Disease, Key Laboratory of Surveillance and Early-warning on Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Junyi Zou
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
| | - Hongjie Yu
- School of Public Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China
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7
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Antigenic distance between North American swine and human seasonal H3N2 influenza A viruses as an indication of zoonotic risk to humans. J Virol 2021; 96:e0137421. [PMID: 34757846 DOI: 10.1128/jvi.01374-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Human-to-swine transmission of influenza A virus (IAV) repeatedly occurs, leading to sustained transmission and increased diversity in swine; human seasonal H3N2 introductions occurred in the 1990s and 2010s and were maintained in North American swine. Swine H3N2 were subsequently associated with zoonotic infections, highlighting the need to understand the risk of endemic swine IAV to humans. We quantified antigenic distances between swine H3N2 and human seasonal vaccine strains from 1973 to 2014 using a panel of monovalent antisera raised in pigs in hemagglutination inhibition (HI) assays. Swine H3N2 lineages retained closest antigenic similarity to human vaccine strains from the decade of incursion. Swine lineages from the 1990s were antigenically more similar to human vaccine strains of the mid-1990s but had substantial distance from recent human vaccine strains. In contrast, lineages from the 2010s were closer to human vaccine strains from 2011 and 2014 and most antigenically distant from human vaccine strains prior to 2007. HI assays using ferret antisera demonstrated that swine lineages from the 1990s and 2010s had significant fold-reduction compared with the homologous HI titer of the nearest pandemic preparedness candidate vaccine virus (CVV) or seasonal vaccine strain. The assessment of post-infection and post-vaccination human sera cohorts demonstrated limited cross-reactivity to swine H3N2 from the 1990s, especially in older adults born before 1970s. We identified swine strains to which humans are likely to lack population immunity or are not protected against by a current human seasonal vaccine or CVV to use in prioritizing future human CVV strain selection. IMPORTANCE Human H3N2 influenza A viruses spread to pigs in North America in the 1990s and more recently in the 2010s. These cross-species events led to sustained circulation and increased H3N2 diversity in pig populations. Evolution of H3N2 in swine led to a reduced similarity with human seasonal H3N2 and the vaccine strains used to protect human populations. We quantified the antigenic phenotypes and found that North American swine H3N2 lineages retained more antigenic similarity to historical human vaccine strains from the decade of incursion but had substantial difference compared with recent human vaccine strains. Additionally, pandemic preparedness vaccine strains demonstrated a loss in similarity with contemporary swine strains. Lastly, human sera revealed that although these adults had antibodies against human H3N2 strains, many had limited immunity to swine H3N2, especially older adults born before 1970. Antigenic assessment of swine H3N2 provides critical information for pandemic preparedness and candidate vaccine development.
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8
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Equine Influenza Virus and Vaccines. Viruses 2021; 13:v13081657. [PMID: 34452521 PMCID: PMC8402878 DOI: 10.3390/v13081657] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/01/2023] Open
Abstract
Equine influenza virus (EIV) is a constantly evolving viral pathogen that is responsible for yearly outbreaks of respiratory disease in horses termed equine influenza (EI). There is currently no evidence of circulation of the original H7N7 strain of EIV worldwide; however, the EIV H3N8 strain, which was first isolated in the early 1960s, remains a major threat to most of the world's horse populations. It can also infect dogs. The ability of EIV to constantly accumulate mutations in its antibody-binding sites enables it to evade host protective immunity, making it a successful viral pathogen. Clinical and virological protection against EIV is achieved by stimulation of strong cellular and humoral immunity in vaccinated horses. However, despite EI vaccine updates over the years, EIV remains relevant, because the protective effects of vaccines decay and permit subclinical infections that facilitate transmission into susceptible populations. In this review, we describe how the evolution of EIV drives repeated EI outbreaks even in horse populations with supposedly high vaccination coverage. Next, we discuss the approaches employed to develop efficacious EI vaccines for commercial use and the existing system for recommendations on updating vaccines based on available clinical and virological data to improve protective immunity in vaccinated horse populations. Understanding how EIV biology can be better harnessed to improve EI vaccines is central to controlling EI.
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McBride DS, Perofsky AC, Nolting JM, Nelson MI, Bowman AS. Tracing the Source of Influenza A Virus Zoonoses in Interconnected Circuits of Swine Exhibitions. J Infect Dis 2021; 224:458-468. [PMID: 33686399 PMCID: PMC7989509 DOI: 10.1093/infdis/jiab122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/01/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Since 2011, influenza A viruses circulating in US swine exhibited at county fairs are associated with >460 zoonotic infections, presenting an ongoing pandemic risk. Swine "jackpot shows" that occur before county fairs each summer intermix large numbers of exhibition swine from diverse geographic locations. We investigated the role of jackpot shows in influenza zoonoses. METHODS We collected snout wipe or nasal swab samples from 17 009 pigs attending 350 national, state, and local swine exhibitions across 8 states during 2016-2018. RESULTS Influenza was detected in 13.9% of swine sampled at jackpot shows, and 76.3% of jackpot shows had at least 1 pig test positive. Jackpot shows had 4.3-fold higher odds of detecting at least 1 influenza-positive pig compared to county fairs. When influenza was detected at a county fair, almost half of pigs tested positive, clarifying why zoonotic infections occur primarily at county fairs. CONCLUSIONS The earlier timing of jackpot shows and long-distance travel for repeated showing of individual pigs provide a pathway for the introduction of influenza into county fairs. Mitigation strategies aimed at curtailing influenza at jackpot shows are likely to have downstream effects on disease transmission at county fairs and zoonoses.
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Affiliation(s)
- Dillon S McBride
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Amanda C Perofsky
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Jacqueline M Nolting
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Martha I Nelson
- Fogarty International Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Andrew S Bowman
- Department of Veterinary Preventive Medicine, The Ohio State University, Columbus, Ohio, USA
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10
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Gomez GB, Mahé C, Chaves SS. Uncertain effects of the pandemic on respiratory viruses. Science 2021; 372:1043-1044. [PMID: 34083477 DOI: 10.1126/science.abh3986] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Gabriela B Gomez
- Department of Modelling, Epidemiology and Data Science, Sanofi Pasteur, Lyon, France. .,Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK
| | - Cedric Mahé
- Department of Modelling, Epidemiology and Data Science, Sanofi Pasteur, Lyon, France.,Foundation for Influenza Epidemiology, Fondation de France, Paris, France
| | - Sandra S Chaves
- Department of Modelling, Epidemiology and Data Science, Sanofi Pasteur, Lyon, France.,Foundation for Influenza Epidemiology, Fondation de France, Paris, France
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11
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Lorbach JN, Fitzgerald T, Nolan C, Nolting JM, Treanor JJ, Topham DJ, Bowman AS. Gaps in Serologic Immunity against Contemporary Swine-Origin Influenza A Viruses among Healthy Individuals in the United States. Viruses 2021; 13:v13010127. [PMID: 33477472 PMCID: PMC7830885 DOI: 10.3390/v13010127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 11/16/2022] Open
Abstract
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.
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Affiliation(s)
- Joshua N. Lorbach
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA; (J.N.L.); (J.M.N.)
| | - Theresa Fitzgerald
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14627, USA; (T.F.); (C.N.); (D.J.T.)
| | - Carolyn Nolan
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14627, USA; (T.F.); (C.N.); (D.J.T.)
| | - Jacqueline M. Nolting
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA; (J.N.L.); (J.M.N.)
| | - John J. Treanor
- Department of Medicine, University of Rochester Medical Center, Rochester, NY 14627, USA;
| | - David J. Topham
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14627, USA; (T.F.); (C.N.); (D.J.T.)
| | - Andrew S. Bowman
- Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA; (J.N.L.); (J.M.N.)
- Correspondence:
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12
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Ma W. Swine influenza virus: Current status and challenge. Virus Res 2020; 288:198118. [PMID: 32798539 PMCID: PMC7587018 DOI: 10.1016/j.virusres.2020.198118] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 08/05/2020] [Accepted: 08/06/2020] [Indexed: 12/19/2022]
Abstract
Since swine influenza virus was first isolated in 1930, it has become endemic in pigs worldwide. Although large amount of swine influenza vaccines has been used in swine industry, swine influenza still cannot be efficiently controlled and has been an important economic disease for swine industry. The high diversity and varied distribution of different subtypes and genotypes of swine influenza viruses circulating in pigs globally is a major challenge to produce broadly effective vaccines and control disease. Importantly, swine influenza virus is able to cross species barrier to infect humans and even caused influenza pandemic in 2009. Herein, current status and challenge of swine influenza viruses is reviewed and discussed.
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Affiliation(s)
- Wenjun Ma
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO 65211, United States.
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13
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Aerosol Transmission from Infected Swine to Ferrets of an H3N2 Virus Collected from an Agricultural Fair and Associated with Human Variant Infections. J Virol 2020; 94:JVI.01009-20. [PMID: 32522849 DOI: 10.1128/jvi.01009-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 05/28/2020] [Indexed: 12/14/2022] Open
Abstract
Influenza A viruses (IAV) sporadically transmit from swine to humans, typically associated with agricultural fairs in the United States. A human seasonal H3 virus from the 2010-2011 IAV season was introduced into the U.S. swine population and termed H3.2010.1 to differentiate it from the previous swine H3 virus. This H3N2 lineage became widespread in the U.S. commercial swine population, subsequently spilling over into exhibition swine, and caused a majority of H3N2 variant (H3N2v) cases in humans in 2016 and 2017. A cluster of human H3N2v cases were reported at an agricultural fair in 2017 in Ohio, where 2010.1 H3N2 IAV was concurrently detected in exhibition swine. Genomic analysis showed that the swine and human isolates were nearly identical. In this study, we evaluated the propensity of a 2010.1 H3N2 IAV (A/swine/Ohio/A01354299/2017 [sw/OH/2017]) isolated from a pig in the agricultural fair outbreak to replicate in ferrets and transmit from swine to ferret. sw/OH/2017 displayed robust replication in the ferret respiratory tract, causing slight fever and moderate weight loss. Further, sw/OH/2017 was capable of efficient respiratory droplet transmission from infected pigs to contact ferrets. These findings establish a model for evaluating the propensity of swine IAV to transmit from pig to ferret as a measure of risk to the human population. The identification of higher-risk swine strains can then be targeted for control measures to limit the dissemination at human-swine interfaces to reduce the risk of zoonotic infections and to inform pandemic planning.IMPORTANCE A recently emerged lineage of human-like H3N2 (H3.2010.1) influenza A virus (IAV) from swine has been frequently detected in commercial and exhibition swine in recent years and has been associated with H3N2 variant cases in humans from 2016 and 2017. To demonstrate a model for characterizing the potential for zoonotic transmission associated with swine IAV, we performed an in vivo study of transmission between pigs infected with an H3.2010.1 H3N2 IAV and aerosol contact ferrets. The efficient interspecies transmission demonstrated for the H3.2010.1 IAV in swine emphasizes the need for further characterization of viruses circulating at the swine-human interface for transmission potential prior to human spillover and the development and implementation of more robust vaccines and control strategies to mitigate human exposure to higher-risk swine strains.
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14
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Pepin KM, Pedersen K, Wan XF, Cunningham FL, Webb CT, Wilber MQ. Individual-Level Antibody Dynamics Reveal Potential Drivers of Influenza A Seasonality in Wild Pig Populations. Integr Comp Biol 2020; 59:1231-1242. [PMID: 31251341 DOI: 10.1093/icb/icz118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Swine are important in the ecology of influenza A virus (IAV) globally. Understanding the ecological role of wild pigs in IAV ecology has been limited because surveillance in wild pigs is often for antibodies (serosurveillance) rather than IAVs, as in humans and domestic swine. As IAV antibodies can persist long after an infection, serosurveillance data are not necessarily indicative of current infection risk. However, antibody responses to IAV infections cause a predictable antibody response, thus time of infection can be inferred from antibody levels in serological samples, enabling identification of risk factors of infection at estimated times of infection. Recent work demonstrates that these quantitative antibody methods (QAMs) can accurately recover infection dates, even when individual-level variation in antibody curves is moderately high. Also, the methodology can be implemented in a survival analysis (SA) framework to reduce bias from opportunistic sampling. Here we integrated QAMs and SA and applied this novel QAM-SA framework to understand the dynamics of IAV infection risk in wild pigs seasonally and spatially, and identify risk factors. We used national-scale IAV serosurveillance data from 15 US states. We found that infection risk was highest during January-March (54% of 61 estimated peaks), with 24% of estimated peaks occurring from May to July, and some low-level of infection risk occurring year-round. Time-varying IAV infection risk in wild pigs was positively correlated with humidity and IAV infection trends in domestic swine and humans, and did not show wave-like spatial spread of infection among states, nor more similar levels of infection risk among states with more similar meteorological conditions. Effects of host sex on IAV infection risk in wild pigs were generally not significant. Because most of the variation in infection risk was explained by state-level factors or infection risk at long-distances, our results suggested that predicting IAV infection risk in wild pigs is complicated by local ecological factors and potentially long-distance translocation of infection. In addition to revealing factors of IAV infection risk in wild pigs, our framework is broadly applicable for quantifying risk factors of disease transmission using opportunistic serosurveillance sampling, a common methodology in wildlife disease surveillance. Future research on the factors that determine individual-level antibody kinetics will facilitate the design of serosurveillance systems that can extract more accurate estimates of time-varying disease risk from quantitative antibody data.
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Affiliation(s)
- Kim M Pepin
- National Wildlife Research Center, USDA-APHIS, Wildlife Services, Fort Collins, CO 80521-2154, USA
| | - Kerri Pedersen
- USDA-APHIS, Wildlife Services, 920 Main Campus Drive, Suite 200, Raleigh, NC 27606, USA
| | - Xiu-Feng Wan
- Missouri University Center for Research on Influenza Systems Biology (CRISB), University of Missouri, Columbia, MO 65211, USA.,Department of Molecular Microbiology and Immunology, School of Medicine, University of Missouri, Columbia, MO, USA.,Department of Electrical Engineering & Computer Science, College of Engineering, University of Missouri, Columbia, MO, USA.,Bond Life Sciences Center, University of Missouri, Columbia, MO, USA.,MU Informatics Institute, University of Missouri, Columbia, MO, USA.,Department of Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | - Fred L Cunningham
- National Wildlife Research Center, USDA-APHIS, Wildlife Services, Mississippi Field Station, MS 39762, USA
| | - Colleen T Webb
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Mark Q Wilber
- National Wildlife Research Center, USDA-APHIS, Wildlife Services, Fort Collins, CO 80521-2154, USA.,Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
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15
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Nirmala J, Bender JB, Lynfield R, Yang M, Rene Culhane M, Nelson MI, Sreevatsan S, Torremorell M. Genetic diversity of influenza A viruses circulating in pigs between winter and summer in a Minnesota live animal market. Zoonoses Public Health 2019; 67:243-250. [PMID: 31868300 DOI: 10.1111/zph.12679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 10/07/2019] [Accepted: 11/19/2019] [Indexed: 11/26/2022]
Abstract
There has been little surveillance of influenza A viruses (IAVs) circulating in swine at live animal markets, particularly in the United States. To address this gap, we conducted active surveillance of IAVs in pigs, the air, and the environment during a summer and winter season in a live animal market in St. Paul, Minnesota, that had been epidemiologically associated with swine-origin influenza cases in humans previously. High rates of IAV were detected by PCR in swine lungs and oral fluids during both summer and winter seasons. Rates of IAV detection by PCR in the air were similar during summer and winter, although rates of successful virus isolation in the air were lower during summer than in winter (26% and 67%, respectively). H3N2 was the most prevalent subtype in both seasons, followed by H1N2. Genetically diverse viruses with multiple gene constellations were isolated from both winter and summer, with a total of 19 distinct genotypes identified. Comparative phylogenetic analysis of all eight segments of 40 virus isolates from summer and 122 isolates from winter revealed that the summer and winter isolates were genetically distinct, indicating IAVs are not maintained in the market, but rather are re-introduced, likely from commercial swine. These findings highlight the extent of IAV genetic diversity circulating in swine in live animal markets, even during summer months, and the ongoing risk to humans.
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Affiliation(s)
- Jayaveeramuthu Nirmala
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA
| | - Jeff B Bender
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA.,School of Public Health, Environmental Health Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Ruth Lynfield
- Minnesota State Health Department, St. Paul, MN, USA
| | - My Yang
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA
| | - Marie Rene Culhane
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA
| | - Martha Irene Nelson
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - Srinand Sreevatsan
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, MI, USA
| | - Montserrat Torremorell
- Veterinary Population Medicine Department, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, USA
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16
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Lauterbach SE, Nelson SW, Robinson ME, Lorbach JN, Nolting JM, Bowman AS. Assessing exhibition swine as potential disseminators of infectious disease through the detection of five respiratory pathogens at agricultural exhibitions. Vet Res 2019; 50:63. [PMID: 31533860 PMCID: PMC6749708 DOI: 10.1186/s13567-019-0684-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 08/27/2019] [Indexed: 11/17/2022] Open
Abstract
Widespread geographic movement and extensive comingling of exhibition swine facilitates the spread and transmission of infectious pathogens. Nasal samples were collected from 2862 pigs at 102 exhibitions and tested for five pathogens. At least one pathogen was molecularly detected in pigs at 63 (61.8%) exhibitions. Influenza A virus was most prevalent and was detected in 498 (17.4%) samples. Influenza D virus was detected in two (0.07%) samples. More than one pathogen was detected in 165 (5.8%) samples. Influenza A virus remains a top threat to animal and human health, but other pathogens may be disseminated through the exhibition swine population.
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Affiliation(s)
- Sarah E Lauterbach
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH, 43210, USA
| | - Sarah W Nelson
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH, 43210, USA
| | - Meghann E Robinson
- Health Science District, University of California Davis, 1 Garrod Drive, Davis, CA, 95616, USA
| | - Josh N Lorbach
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH, 43210, USA
| | - Jacqueline M Nolting
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH, 43210, USA
| | - Andrew S Bowman
- Department of Veterinary Preventive Medicine, The Ohio State University, 1920 Coffey Road, Columbus, OH, 43210, USA.
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17
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Virus survival and fitness when multiple genotypes and subtypes of influenza A viruses exist and circulate in swine. Virology 2019; 532:30-38. [PMID: 31003122 DOI: 10.1016/j.virol.2019.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/21/2019] [Accepted: 03/26/2019] [Indexed: 01/07/2023]
Abstract
We performed swine influenza virus (SIV) surveillance in Midwest USA and isolated 100 SIVs including endemic and reassortant H1 and H3 viruses with 2009 pandemic H1N1 genes. To determine virus evolution when different genotypes and subtypes of influenza A viruses circulating in the same swine herd, a virus survival experiment was conducted in pigs mimicking field situations. Five different SIVs were used to infect five pigs individually, then two groups of sentinel pigs were introduced to investigate virus transmission. Results showed that each virus replicated efficiently in lungs of each infected pig, but only reassortant H3N2 and H1N2v viruses transmitted to the primary contact pigs. Interestingly, the parental H1N2v was the majority of virus detected in the second group of sentinel pigs. These data indicate that the H1N2v seems to be more viable in swine herds than other SIV genotypes, and reassortment can enhance viral fitness and transmission.
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18
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Bolton MJ, Abente EJ, Venkatesh D, Stratton JA, Zeller M, Anderson TK, Lewis NS, Vincent AL. Antigenic evolution of H3N2 influenza A viruses in swine in the United States from 2012 to 2016. Influenza Other Respir Viruses 2018; 13:83-90. [PMID: 30216671 PMCID: PMC6304321 DOI: 10.1111/irv.12610] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 08/31/2018] [Accepted: 09/05/2018] [Indexed: 12/27/2022] Open
Abstract
Background Six amino acid positions (145, 155, 156, 158, 159, and 189, referred to as the antigenic motif; H3 numbering) in the globular head region of hemagglutinin (HA1 domain) play an important role in defining the antigenic phenotype of swine Clade IV (C‐IV) H3N2 IAV, containing an H3 from a late 1990s human‐to‐swine introduction. We hypothesized that antigenicity of a swine C‐IV H3 virus could be inferred based upon the antigenic motif if it matched a previously characterized antigen with the same motif. An increasing number of C‐IV H3 genes encoding antigenic motifs that had not been previously characterized were observed in the U.S. pig population between 2012 and 2016. Objectives A broad panel of contemporary H3 viruses with uncharacterized antigenic motifs was selected across multiple clades within C‐IV to assess the impact of HA1 genetic diversity on the antigenic phenotype. Methods Hemagglutination inhibition (HI) assays were performed with isolates selected based on antigenic motif, tested against a panel of swine antisera, and visualized by antigenic cartography. Results A previously uncharacterized motif with low but sustained circulation in the swine population demonstrated a distinct phenotype from those previously characterized. Antigenic variation increased for viruses with similar antigenic motifs, likely due to amino acid substitutions outside the motif. Conclusions Although antigenic motifs were largely associated with antigenic distances, substantial diversity among co‐circulating viruses poses a significant challenge for effective vaccine development. Continued surveillance and antigenic characterization of circulating strains is critical for improving vaccine efforts to control C‐IV H3 IAV in U.S. swine.
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Affiliation(s)
- Marcus J Bolton
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa
| | - Eugenio J Abente
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa
| | - Divya Venkatesh
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Jered A Stratton
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa
| | - Michael Zeller
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa.,Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa
| | - Tavis K Anderson
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa
| | - Nicola S Lewis
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Amy L Vincent
- Virus and Prion Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa
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19
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Bowman AS, Walia RR, Nolting JM, Vincent AL, Killian ML, Zentkovich MM, Lorbach JN, Lauterbach SE, Anderson TK, Davis CT, Zanders N, Jones J, Jang Y, Lynch B, Rodriguez MR, Blanton L, Lindstrom SE, Wentworth DE, Schiltz J, Averill JJ, Forshey T. Influenza A(H3N2) Virus in Swine at Agricultural Fairs and Transmission to Humans, Michigan and Ohio, USA, 2016. Emerg Infect Dis 2018; 23:1551-1555. [PMID: 28820376 PMCID: PMC5572863 DOI: 10.3201/eid2309.170847] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
In 2016, a total of 18 human infections with influenza A(H3N2) virus occurred after exposure to influenza-infected swine at 7 agricultural fairs. Sixteen of these cases were the result of infection by a reassorted virus with increasing prevalence among US swine containing a hemagglutinin gene from 2010–11 human seasonal H3N2 strains.
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20
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Stewart RJ, Rossow J, Conover JT, Lobelo EE, Eckel S, Signs K, Stobierski MG, Trock SC, Fry AM, Olsen SJ, Biggerstaff M. Do animal exhibitors support and follow recommendations to prevent transmission of variant influenza at agricultural fairs? A survey of animal exhibitor households after a variant influenza virus outbreak in Michigan. Zoonoses Public Health 2017; 65:195-201. [PMID: 29143461 PMCID: PMC6631301 DOI: 10.1111/zph.12425] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Indexed: 11/30/2022]
Abstract
Influenza A viruses circulate in swine and can spread rapidly among swine when housed in close proximity, such as at agricultural fairs. Youth who have close and prolonged contact with influenza-infected swine at agricultural fairs may be at increased risk of acquiring influenza virus infection from swine. Animal and human health officials have issued written measures to minimize influenza transmission at agricultural exhibitions; however, there is little information on the knowledge, attitudes, and practice (KAP) of these measures among animal exhibitors. After an August 2016 outbreak of influenza A(H3N2) variant (“H3N2v”) virus infections (i.e., humans infected with swine influenza viruses) in Michigan, we surveyed households of animal exhibitors at eight fairs (including one with known H3N2v infections) to assess their KAP related to variant virus infections and their support for prevention measures. Among 170 households interviewed, most (90%, 151/167) perceived their risk of acquiring influenza from swine to be low or very low. Animal exhibitor households reported high levels of behaviours that put them at increased risk of variant influenza virus infections, including eating or drinking in swine barns (43%, 66/154) and hugging, kissing or snuggling with swine at agricultural fairs (31%, 48/157). Among several recommendations, including limiting the duration of swine exhibits and restricting eating and drinking in the animal barns, the only recommendation supported by a majority of households was the presence of prominent hand-washing stations with a person to monitor hand-washing behaviour (76%, 129/170). This is a unique study of KAP among animal exhibitors and highlights that animal exhibitor households engage in behaviours that could increase their risk of variant virus infections and have low support for currently recommended measures to minimize infection transmission. Further efforts are needed to understand the lack of support for recommended measures and to encourage healthy behaviours at fairs.
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Affiliation(s)
- R J Stewart
- Epidemic Intelligence Service, CDC, Atlanta, GA, USA.,Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - J Rossow
- Epidemiology Elective Program, Division of Scientific Education and Professional Development, Center for Surveillance, Epidemiology, and Laboratory Services, Atlanta, GA, USA.,University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - J T Conover
- Michigan State University Extension, East Lansing, MI, USA
| | - E E Lobelo
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - S Eckel
- Michigan Department of Health and Human Services, Lansing, MI, USA
| | - K Signs
- Michigan Department of Health and Human Services, Lansing, MI, USA
| | - M G Stobierski
- Michigan Department of Health and Human Services, Lansing, MI, USA
| | - S C Trock
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - A M Fry
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - S J Olsen
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M Biggerstaff
- Influenza Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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21
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Nelson MI, Culhane MR, Trovão NS, Patnayak DP, Halpin RA, Lin X, Shilts MH, Das SR, Detmer SE. The emergence and evolution of influenza A (H1α) viruses in swine in Canada and the United States. J Gen Virol 2017; 98:2663-2675. [PMID: 29058649 DOI: 10.1099/jgv.0.000924] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Swine are a key reservoir host for influenza A viruses (IAVs), with the potential to cause global pandemics in humans. Gaps in surveillance in many of the world's largest swine populations impede our understanding of how novel viruses emerge and expand their spatial range in pigs. Although US swine are intensively sampled, little is known about IAV diversity in Canada's population of ~12 million pigs. By sequencing 168 viruses from multiple regions of Canada, our study reveals that IAV diversity has been underestimated in Canadian pigs for many years. Critically, a new H1 clade has emerged in Canada (H1α-3), with a two-amino acid deletion at H1 positions 146-147, that experienced rapid growth in Manitoba's swine herds during 2014-2015. H1α-3 viruses also exhibit a higher capacity to invade US swine herds, resulting in multiple recent introductions of the virus into the US Heartland following large-scale movements of pigs in this direction. From the Heartland, H1α-3 viruses have disseminated onward to both the east and west coasts of the United States, and may become established in Appalachia. These findings demonstrate how long-distance trading of live pigs facilitates the spread of IAVs, increasing viral genetic diversity and complicating pathogen control. The proliferation of novel H1α-3 viruses also highlights the need for expanded surveillance in a Canadian swine population that has long been overlooked, and may have implications for vaccine design.
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Affiliation(s)
- Martha I Nelson
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | | | - Nídia S Trovão
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.,Icahn School of Medicine at Mount Sinai University, New York, USA
| | | | | | - Xudong Lin
- J. Craig Venter Institute, Rockville, MD, USA
| | - Meghan H Shilts
- J. Craig Venter Institute, Rockville, MD, USA.,Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Suman R Das
- J. Craig Venter Institute, Rockville, MD, USA.,Vanderbilt University School of Medicine, Nashville, TN, USA
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22
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Lorbach JN, Wang L, Nolting JM, Benjamin MG, Killian ML, Zhang Y, Bowman AS. Porcine Hemagglutinating Encephalomyelitis Virus and Respiratory Disease in Exhibition Swine, Michigan, USA, 2015. Emerg Infect Dis 2017; 23. [PMID: 28628449 PMCID: PMC5512476 DOI: 10.3201/eid2307.170019] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Acute outbreaks of respiratory disease in swine at agricultural fairs in Michigan, USA, in 2015 raised concern for potential human exposure to influenza A virus. Testing ruled out influenza A virus and identified porcine hemagglutinating encephalomyelitis virus as the cause of influenza-like illness in the affected swine.
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23
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Lorbach JN, Wang L, Nolting JM, Benjamin MG, Killian ML, Zhang Y, Bowman AS. Porcine Hemagglutinating Encephalomyelitis Virus and Respiratory Disease in Exhibition Swine, Michigan, USA, 2015. Emerg Infect Dis 2017. [DOI: 10.3201/eid2307.17-0019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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