Highly Pathogenic Avian Influenza H5N8 Clade 2.3.4.4 Virus: Equivocal Pathogenicity and Implications for Surveillance Following Natural Infection in Breeder Ducks in the United Kingdom
| Autor: | James Seekings, Sharon M. Brookes, Alejandro Núñez, Y. I. Spencer, Scott M. Reid, Ian H. Brown, D. Hicks, Cristina Garcia-Rueda |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty animal diseases Peritonitis Biology medicine.disease_cause Virus Disease Outbreaks Gross examination 03 medical and health sciences medicine Animals Poultry Diseases Air sacs Virulence General Veterinary General Immunology and Microbiology Outbreak General Medicine medicine.disease Virology United Kingdom Influenza A virus subtype H5N1 Ducks 030104 developmental biology Influenza A virus Influenza in Birds Granuloma Female Histopathology |
| Zdroj: | Transboundary and Emerging Diseases. 63:5-9 |
| ISSN: | 1865-1674 |
| DOI: | 10.1111/tbed.12442 |
| Popis: | Since early 2014, several outbreaks involving novel reassortant highly pathogenic avian influenza (HPAI) A(H5N8) viruses have been detected in poultry and wild bird species in Asia, Europe and North America. These viruses have been detected in apparently healthy and dead wild migratory birds, as well as in domestic chickens, turkeys, geese and ducks. In this study, we describe the pathology of an outbreak of H5N8 HPAIV in breeder ducks in the UK. A holding with approximately 6000 breeder ducks, aged approximately 60 weeks, showed a gradual reduction in egg production and increased mortality over a 7-day period. Post-mortem examination revealed frequent fibrinous peritonitis, with severely haemorrhagic ovarian follicles and occasional splenic and pancreatic necrosis and high incidence of mycotic granulomas in the air sacs and lung. Low-to-moderate levels of HPAI H5N8 virus were detected mainly in respiratory and digestive tract, with minor involvement of other organs. Although histopathological examination confirmed the gross pathology findings, intralesional viral antigen detection by immunohistochemistry was not observed. Immunolabelled cells were rarely only present in inflamed air sacs and serosa, usually superficial to granulomatous inflammation. Abundant bacterial microcolonies were observed in haemorrhagic ovaries and oviduct. The limited viral tissue distribution and presence of inter-current fungal and bacterial infections suggest a minor role for HPAIV H5N8 in clinical disease in layer ducks. |
| Databáze: | OpenAIRE |
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