Researchers have found a new type of avian influenza virus in a group of Adélie penguins (pygoscelies adeliae) from Antarctica. Aeron Hurt, PhD, a senior research scientist at the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, Australia, said that this is the first time that a distinct, live flu virus has been found in these birds.
For the study, researchers obtained swabs from the windpipes and posterior openings of 301 Adélie penguins and blood samples from 270 penguins.
The team used real-time reverse transcription-PCR and found the virus in eight (2.7%) samples. Researchers were able to grow the virus in a lab, showing that they were live viruses. Further research found that the virus in birds were similar and were H11N2 influenza viruses.
However, when researchers compared the genome of the virus to that of other such viruses, We found that this virus was unlike anything else detected in the world, said Hurt. When we drew phylogenetic trees to show the evolutionary relationships of the virus, all of the genes were highly distinct from contemporary AIVs circulating in other continents in either the Northern or Southern Hemisphere.
Some of the genes in the new virus were linked to North American avian lineage viruses from the 1960s to 1980s and few from South American AIVs from Chile. According to researchers, the virus had been evolving for the past 49-80 years. The team isn't sure whether or not the virus exclusively evolved in Antarctica.
No one knows how the virus reached Antarctica. Birds living in Polar Regions are known to migrate to other parts of the world, so they might have transported the virus. Another suspect is the yellow-billed pintail duck, which is known to travel from South America to reach Antarctic Peninsula.
Additional research showed that the virus didn't infect other birds or animals such as ferrets.
The virus doesn't cause any disease in penguins, but the study shows that avian influenza viruses can get down to Antarctica and be maintained in penguin populations, Hurt said. It raises a lot of unanswered questions.
The study is published in the journal mBio®. Instituto Antártico Chileno (Chilean Antarctic Institute) and Australian Government Department of Health funded the research.