Commercial poultry should be protected from the risk of contracting avian influenza strains from migrating flocks, according to new research led by The Roslin Institute in the U.K.

New insights from a study of the 2016-17 avian flu outbreak show how highly pathogenic avian flu viruses — which are likely to cause deadly disease in chickens — can be transmitted from migrating wild bird populations to domestic flocks and back again, the institute said in an announcement.

These viruses can readily exchange genetic material with other low-pathogenic, less harmful viruses during migration, raising the likelihood of serious outbreaks in domesticated poultry and wild birds, the researchers found.

A team of researchers that included The Roslin Institute, representing the Global Consortium for H5N8 & Related Influenza Viruses, studied the genetic makeup of the 2016-17 avian flu virus in various birds at key stages during the flu season, the announcement said. The study offers insights into the outbreak strains, which originated in domesticated birds in Asia before spreading via wild migratory flocks to create Europe's largest avian influenza epidemic to date.

Genetic analyses

The team interpreted genetic sequencing data from virus samples collected during the outbreak, along with details of where, when and in which bird species they originated, Roslin said.

The researchers used a computational technique known as phylogenetic inference to estimate when and where the virus exchanged genetic material with other viruses in wild or domesticated birds.

The virus could easily exchange genetic material with other less harmful viruses at times and locations that corresponded to birds' migratory cycles, the results showed. These included viruses carried by wild birds on intersecting migratory routes and by farmed ducks in China and Central Europe, Roslin noted.

Migrating birds harboring weaker viruses are more likely to survive their journey and potentially pass disease to domestic birds.

"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," Dr. Sam Lycett with Roslin said.

The research, to be published in Proceedings of the National Academy of Sciences, was carried out in collaboration with the Friedrich Loeffler Institut in Germany, the Erasmus University Medical Center in the Netherlands and the University of Edinburgh’s Usher Institute and Roslin Institute.