Distinct Avian Influenza Virus Identified in Antarctica Penguins

An international team of researchers has identified a distinct avian influenza virus in a group of Antarctica's Adelie penguins.

According to the finding documented in the journal of American Society of Microbiology, the avian influenza virus is different from the circulating avian flu. 

Studies conducted earlier did not detect the live influenza virus in Antarctic's penguins or other birds.

The study was led by associate professor Aeron Hurt, PhD, a senior research scientist at the WHO Collaborating Centre for Reference and Research on Influenza in Melbourne, Australia.

The researchers worked on the swab samples taken from Adelie penguins' windpipes. They also collected samples from posterior openings. Apart from this, blood samples from 270 penguins were taken from two sites on the Antarctic Peninsula.

The two regions included Admiralty Bay and Rada Covadonga. All the samples were collected during January and February 2013.

 With the help of real-time reverse transcription-PCR, a lab technique, the researchers detected the genetic material of distinct avian influenza virus in eight samples  out of which two were chicks and six were adults.  Seven samples belonged to the Penguins of Rada Covadonga.

The team could also successfully culture four of the viruses clearly indicating the presence of live virus.  Further analysis showed that all the viruses were H11N2 influenza viruses that were highly analogous.

On evaluating the complete genome sequence of the four viruses against the available human and animal influenza virus sequences, the researchers noticed that the virus was distinct and new.

"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."

There were four gene segments that were closely linked to the 1960s-1980s North American avian virus. Two other genes had a distant association with  majority of the South American AIVs from Chile, Argentina and Brazil.

Based on the molecular clock the researchers estimate that the virus evolved in the last  49-80 years. What remains a mystery is whether their evolution is just limited to Antarctica.

Experiments also showed that 43 of the 270 Antarctic Penguins had influenza A antibodies in their blood and the new distinct avian influenza was in birds and not mammals.

The study shows that " the avian influenza viruses can get down to Antarctica and be maintained in penguin populations. It raises a lot of unanswered questions including how often AIVs are being introduced into Antarctica, whether it is possible for highly pathogenic AIVs to be transferred there, what animals or ecosystems are maintaining the virus, and whether the viruses are being cryopreserved during the winters."