Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort

Background: Pigs are mixing vessels for influenza viral reassortment but the extent of influenza transmission between swine and humans is not well understood. Objectives: To assess whether occupational exposure to pigs is a risk factor for human infection with human and swine-adapted influenza...

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Main Authors: Fragaszy, Ellen, Ishola, David A., Brown, Ian H., Enstone, Joanne, Nguyen-Van-Tam, Jonathan S., Simons, Robin, Tucker, Alexander W., Wieland, Barbara, Williamson, Susanna M., Hayward, Andrew C., Wood, James L.N.
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Published: Wiley 2016
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Online Access:https://eprints.nottingham.ac.uk/34446/
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author Fragaszy, Ellen
Ishola, David A.
Brown, Ian H.
Enstone, Joanne
Nguyen-Van-Tam, Jonathan S.
Simons, Robin
Tucker, Alexander W.
Wieland, Barbara
Williamson, Susanna M.
Hayward, Andrew C.
Wood, James L.N.
author_facet Fragaszy, Ellen
Ishola, David A.
Brown, Ian H.
Enstone, Joanne
Nguyen-Van-Tam, Jonathan S.
Simons, Robin
Tucker, Alexander W.
Wieland, Barbara
Williamson, Susanna M.
Hayward, Andrew C.
Wood, James L.N.
author_sort Fragaszy, Ellen
building Nottingham Research Data Repository
collection Online Access
description Background: Pigs are mixing vessels for influenza viral reassortment but the extent of influenza transmission between swine and humans is not well understood. Objectives: To assess whether occupational exposure to pigs is a risk factor for human infection with human and swine-adapted influenza viruses. Methods: UK pig industry workers were frequency-matched on age, region, sampling month, and gender with a community-based comparison group from the Flu Watch study. HI assays quantified antibodies for swine and human A(H1) and A(H3) influenza viruses (titres≥40 considered seropositive and indicative of infection). Virus-specific associations between seropositivity and occupational pig exposure were examined using multivariable regression models adjusted for vaccination. Pigs on the same farms were also tested for seropositivity. Results: 42% of pigs were seropositive to A(H1N1)pdm09. Pig industry workers showed evidence of increased odds of A(H1N1)pdm09 seropositivity compared to the comparison group, albeit with wide confidence intervals (CI), Adjusted Odds Ratio after accounting for possible cross reactivity with other swine A(H1) viruses (aOR) 25.30, 95% CI [1.44-536.34], p=0.028. Conclusion: The results indicate that A(H1N1)pdm09 virus was common in UK pigs during the pandemic and subsequent period of human A(H1N1)pdm09 circulation, and occupational exposure to pigs was a risk factor for human infection. Influenza immunization of pig industry workers may reduce transmission and the potential for virus reassortment.
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spelling nottingham-344462020-05-04T17:29:40Z https://eprints.nottingham.ac.uk/34446/ Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort Fragaszy, Ellen Ishola, David A. Brown, Ian H. Enstone, Joanne Nguyen-Van-Tam, Jonathan S. Simons, Robin Tucker, Alexander W. Wieland, Barbara Williamson, Susanna M. Hayward, Andrew C. Wood, James L.N. Background: Pigs are mixing vessels for influenza viral reassortment but the extent of influenza transmission between swine and humans is not well understood. Objectives: To assess whether occupational exposure to pigs is a risk factor for human infection with human and swine-adapted influenza viruses. Methods: UK pig industry workers were frequency-matched on age, region, sampling month, and gender with a community-based comparison group from the Flu Watch study. HI assays quantified antibodies for swine and human A(H1) and A(H3) influenza viruses (titres≥40 considered seropositive and indicative of infection). Virus-specific associations between seropositivity and occupational pig exposure were examined using multivariable regression models adjusted for vaccination. Pigs on the same farms were also tested for seropositivity. Results: 42% of pigs were seropositive to A(H1N1)pdm09. Pig industry workers showed evidence of increased odds of A(H1N1)pdm09 seropositivity compared to the comparison group, albeit with wide confidence intervals (CI), Adjusted Odds Ratio after accounting for possible cross reactivity with other swine A(H1) viruses (aOR) 25.30, 95% CI [1.44-536.34], p=0.028. Conclusion: The results indicate that A(H1N1)pdm09 virus was common in UK pigs during the pandemic and subsequent period of human A(H1N1)pdm09 circulation, and occupational exposure to pigs was a risk factor for human infection. Influenza immunization of pig industry workers may reduce transmission and the potential for virus reassortment. Wiley 2016-01-29 Article PeerReviewed Fragaszy, Ellen, Ishola, David A., Brown, Ian H., Enstone, Joanne, Nguyen-Van-Tam, Jonathan S., Simons, Robin, Tucker, Alexander W., Wieland, Barbara, Williamson, Susanna M., Hayward, Andrew C. and Wood, James L.N. (2016) Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort. Influenza and Other Respiratory Viruses, 10 (4). pp. 291-300. ISSN 1750-2659 Humans influenza occupational exposure serology swine zoonoses http://onlinelibrary.wiley.com/doi/10.1111/irv.12364/abstract doi: 10.1111/irv.12364 doi: 10.1111/irv.12364
spellingShingle Humans
influenza
occupational exposure
serology
swine zoonoses
Fragaszy, Ellen
Ishola, David A.
Brown, Ian H.
Enstone, Joanne
Nguyen-Van-Tam, Jonathan S.
Simons, Robin
Tucker, Alexander W.
Wieland, Barbara
Williamson, Susanna M.
Hayward, Andrew C.
Wood, James L.N.
Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title_full Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title_fullStr Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title_full_unstemmed Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title_short Increased risk of A(H1N1)pdm09 influenza infection in UK pig industry workers compared to a general population cohort
title_sort increased risk of a(h1n1)pdm09 influenza infection in uk pig industry workers compared to a general population cohort
topic Humans
influenza
occupational exposure
serology
swine zoonoses
url https://eprints.nottingham.ac.uk/34446/
https://eprints.nottingham.ac.uk/34446/
https://eprints.nottingham.ac.uk/34446/