Commercial poultry should be protected from the risk of contracting harmful bird flu from migrating flocks, according to new research.
Insights from a study of the devastating 2017/17 bird flu outbreak show how highly pathogenic bird flu viruses can be transmitted from wild migrating bird population to domestic flocks and back again.
These viruses can readily exchange genetic material with other low pathogenic viruses – which are less harmful – during migration, raising the likelihood of serious outbreaks in domestic poultry and wild birds.
The study, led by a team including the Roslin Institute, representing the Global Consortium for H5N8 and Related Influenza Viruses, studied the genetic makeup of the 2016/7 bird flu virus in various birds at key stages during the flu season. The outbreak began in domestic birds in Asia before being spread via wild migratory flocks to create the largest bird flu epidemic in Europe to date. The team interpreted genetic sequence data from virus samples collected during the outbreak, together with details of where, when and in which bird species they originated. Using a computational technique, known as phylogenetic inference, researchers estimated where and when the virus exchanged genetic material with other viruses in wild or domestic birds.
The virus could easily exchange genetic material with other, less harmful viruses, at times and locations corresponding to bird migratory cycles. These included viruses carried by wild birds on intersecting migratory routes and by farmed ducks in China and central Europe. Migratory birds harbouring weaker viruses are more likely to survive their journey and potentially pass disease to domestic birds, the study found.
Bird flu viruses can readily exchange genetic material with other influenza viruses…”
Commenting on the results, Dr Sam Lycett of the Roslin Institute, said: “Bird flu viruses can readily exchange genetic material with other influenza viruses and this, in combination with repeated transmission of viruses between domestic and wild birds, means that a viral strain can emerge and persist in wild bird populations, which carries a high risk of disease for poultry. This aids our understanding of how a pathogenic avian flu virus could become established in wild bird populations.”
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The research, published in Proceedings of the National Academy of Sciences, was carried out in collaboration with the Friedrich Loeffler Institute, Germany, the Erasmus University Medical Centre, Holland and the University of Edinburgh’s Usher Institute and Roslin Institute. It was supported by funding from EU Horizon 2020 and others.