Evaluating the Impact of Low-Pathogenicity Avian Influenza H6N1 Outbreaks in United Kingdom and Republic of Ireland Poultry Farms during 2020
Michael J. McMenamy,
Robyn McKenna,
Valerie B. Bailie,
Ben Cunningham,
Adam Jeffers,
Kelly McCullough,
Catherine Forsythe,
Laura Garza Cuartero,
Orla Flynn,
Christina Byrne,
Emily Connaghan,
John Moriarty,
June Fanning,
Stephanie Ronan,
Damien Barrett,
Alice Fusaro,
Isabella Monne,
Calogero Terregino,
Joe James,
Alexander M. P. Byrne,
Fabian Z. X. Lean,
Alejandro Núñez,
Scott M. Reid,
Rowena Hansen,
Ian H. Brown,
Ashley C. Banyard,
Ken Lemon
Affiliations
Michael J. McMenamy
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Robyn McKenna
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Valerie B. Bailie
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Ben Cunningham
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Adam Jeffers
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Kelly McCullough
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Catherine Forsythe
Disease Surveillance & Investigation Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
Laura Garza Cuartero
Central Veterinary Research Laboratory, DAFM, Backweston Campus, Stacummy Lane, W23 X3PH Celbridge, Ireland
Orla Flynn
Central Veterinary Research Laboratory, DAFM, Backweston Campus, Stacummy Lane, W23 X3PH Celbridge, Ireland
Christina Byrne
Central Veterinary Research Laboratory, DAFM, Backweston Campus, Stacummy Lane, W23 X3PH Celbridge, Ireland
Emily Connaghan
Central Veterinary Research Laboratory, DAFM, Backweston Campus, Stacummy Lane, W23 X3PH Celbridge, Ireland
John Moriarty
Central Veterinary Research Laboratory, DAFM, Backweston Campus, Stacummy Lane, W23 X3PH Celbridge, Ireland
June Fanning
National Disease Control Centre, Department of Agriculture, Food and the Marine, Agriculture House, Kildare Street, D02 WK12 Dublin, Ireland
Stephanie Ronan
National Disease Control Centre, Department of Agriculture, Food and the Marine, Agriculture House, Kildare Street, D02 WK12 Dublin, Ireland
Damien Barrett
National Disease Control Centre, Department of Agriculture, Food and the Marine, Agriculture House, Kildare Street, D02 WK12 Dublin, Ireland
Alice Fusaro
European Union Reference Laboratory (EURL) for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Padua, Italy
Isabella Monne
European Union Reference Laboratory (EURL) for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Padua, Italy
Calogero Terregino
European Union Reference Laboratory (EURL) for Avian Influenza and Newcastle Disease, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Padua, Italy
Joe James
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Alexander M. P. Byrne
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Fabian Z. X. Lean
Pathology and Animal Sciences Department, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Alejandro Núñez
Pathology and Animal Sciences Department, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Scott M. Reid
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Rowena Hansen
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Ian H. Brown
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Ashley C. Banyard
Department of Virology, Animal and Plant Health Agency—Weybridge, Woodham Lane, New Haw, Addlestone KT15 3NB, UK
Ken Lemon
Virological Molecular Diagnostics Laboratory, Virology Branch, Agri-Food and Bioscience Institute, Stoney Road, Stormont, Belfast BT4 3SD, UK
In January 2020, increased mortality was reported in a small broiler breeder flock in County Fermanagh, Northern Ireland. Gross pathological findings included coelomitis, oophoritis, salpingitis, visceral gout, splenomegaly, and renomegaly. Clinical presentation included inappetence, pronounced diarrhoea, and increased egg deformation. These signs, in combination with increased mortality, triggered a notifiable avian disease investigation. High pathogenicity avian influenza virus (HPAIV) was not suspected, as mortality levels and clinical signs were not consistent with HPAIV. Laboratory investigation demonstrated the causative agent to be a low-pathogenicity avian influenza virus (LPAIV), subtype H6N1, resulting in an outbreak that affected 15 premises in Northern Ireland. The H6N1 virus was also associated with infection on 13 premises in the Republic of Ireland and six in Great Britain. The close genetic relationship between the viruses in Ireland and Northern Ireland suggested a direct causal link whereas those in Great Britain were associated with exposure to a common ancestral virus. Overall, this rapidly spreading outbreak required the culling of over 2 million birds across the United Kingdom and the Republic of Ireland to stamp out the incursion. This report demonstrates the importance of investigating LPAIV outbreaks promptly, given their substantial economic impacts.
