mBio (Aug 2022)
Has Epizootic Become Enzootic? Evidence for a Fundamental Change in the Infection Dynamics of Highly Pathogenic Avian Influenza in Europe, 2021
- Anne Pohlmann,
- Jacqueline King,
- Alice Fusaro,
- Bianca Zecchin,
- Ashley C. Banyard,
- Ian H. Brown,
- Alexander M. P. Byrne,
- Nancy Beerens,
- Yuan Liang,
- Rene Heutink,
- Frank Harders,
- Joe James,
- Scott M. Reid,
- Rowena D. E. Hansen,
- Nicola S. Lewis,
- Charlotte Hjulsager,
- Lars E. Larsen,
- Siamak Zohari,
- Kristofer Anderson,
- Caroline Bröjer,
- Alexander Nagy,
- Vladimir Savič,
- Steven van Borm,
- Mieke Steensels,
- Francois-Xavier Briand,
- Edyta Swieton,
- Krzysztof Smietanka,
- Christian Grund,
- Martin Beer,
- Timm Harder
Affiliations
- Anne Pohlmann
- Institute of Diagnostic Virology, Friedrich Loeffler Institute, Greifswald-Insel Riems, Germany
- Jacqueline King
- Institute of Diagnostic Virology, Friedrich Loeffler Institute, Greifswald-Insel Riems, Germany
- Alice Fusaro
- European Union Reference Laboratory for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padua, Italy
- Bianca Zecchin
- European Union Reference Laboratory for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padua, Italy
- Ashley C. Banyard
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Ian H. Brown
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Alexander M. P. Byrne
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Nancy Beerens
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Yuan Liang
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
- Rene Heutink
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Frank Harders
- Wageningen Bioveterinary Research, Lelystad, The Netherlands
- Joe James
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Scott M. Reid
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Rowena D. E. Hansen
- Animal and Plant Health Agency—Weybridge, New Haw, Addlestone, Surrey, United Kingdom
- Nicola S. Lewis
- Department of Pathobiology and Population Sciences, Royal Veterinary College, Hatfield, United Kingdom
- Charlotte Hjulsager
- Department for Virus and Microbiological Special Diagnostics, Statens Serum Institut, Copenhagen, Denmark
- Lars E. Larsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Frederiksberg, Denmark
- Siamak Zohari
- Department of Microbiology, National Veterinary Institute, SVA, Uppsala, Sweden
- Kristofer Anderson
- Department of Microbiology, National Veterinary Institute, SVA, Uppsala, Sweden
- Caroline Bröjer
- Department of Pathology, National Veterinary Institute, SVA, Uppsala, Sweden
- Alexander Nagy
- State Veterinary Institute Prague, Prague, Czech Republic
- Vladimir Savič
- Croatian Veterinary Institute, Poultry Centre, Zagreb, Croatia
- Steven van Borm
- Service of Avian Virology and Immunology, Sciensano, Brussels, Belgium
- Mieke Steensels
- Service of Avian Virology and Immunology, Sciensano, Brussels, Belgium
- Francois-Xavier Briand
- Agence Nationale de Sécurité Sanitaire, de l’Alimentation, de l’Environnement et du Travail, Laboratoire de Ploufragan-Plouzané-Niort, Unité de Virologie, Immunologie, Parasitologie Avaires et Cunicoles, Ploufragan, France
- Edyta Swieton
- Department of Poultry Diseases, National Veterinary Research Institute, Puławy, Poland
- Krzysztof Smietanka
- Department of Poultry Diseases, National Veterinary Research Institute, Puławy, Poland
- Christian Grund
- Institute of Diagnostic Virology, Friedrich Loeffler Institute, Greifswald-Insel Riems, Germany
- Martin Beer
- Institute of Diagnostic Virology, Friedrich Loeffler Institute, Greifswald-Insel Riems, Germany
- Timm Harder
- Institute of Diagnostic Virology, Friedrich Loeffler Institute, Greifswald-Insel Riems, Germany
- DOI
- https://doi.org/10.1128/mbio.00609-22
- Journal volume & issue
-
Vol. 13,
no. 4
Abstract
ABSTRACT Phylogenetic evidence from the recent resurgence of high-pathogenicity avian influenza (HPAI) virus subtype H5N1, clade 2.3.4.4b, observed in European wild birds and poultry since October 2021, suggests at least two different and distinct reservoirs. We propose contrasting hypotheses for this emergence: (i) resident viruses have been maintained, presumably in wild birds, in northern Europe throughout the summer of 2021 to cause some of the outbreaks that are part of the most recent autumn/winter 2021 epizootic, or (ii) further virus variants were reintroduced by migratory birds, and these two sources of reintroduction have driven the HPAI resurgence. Viruses from these two principal sources can be distinguished by their hemagglutinin genes, which segregate into two distinct sublineages (termed B1 and B2) within clade 2.3.4.4b, as well as their different internal gene compositions. The evidence of enzootic HPAI virus circulation during the summer of 2021 indicates a possible paradigm shift in the epidemiology of HPAI in Europe.
Keywords
