A new bird flu strain, H11N2, has been identified and confirmed by researchers in Australia. The strain is infecting Adélie penguins in Antarctica but has no obvious symptoms.

"We found that this virus was unlike anything else detected in the world," said Aeron Hurt, a senior flu researcher with the World Health Organization. Hurt and her colleagues are conducting research as part of WHO's Collaborating Center for Reference and Research on Influenza in Melbourne, Australia.

The researchers have been collecting penguin blood samples, as well as throat and cloaca swabs, from several hundred penguins living on the South Pole. Of the many samples, only eight tested positive for the avian influenza virus. Other penguins showed evidence of influenza antibodies.

"When we drew phylogenetic trees to show the evolutionary relationships of the virus, all of the genes were highly distinct from contemporary [avian influenza viruses] circulating in other continents in either the Northern or Southern Hemisphere."

The genetic analysis revealed that this specific bird flu strain is most closely related to H3N8, a strain from the 1960s.

The researchers claim the infected birds don't appear to be sick or suffering any symptoms as the result of the flu, and when exposed to the strain, lab ferrets were unaffected -- suggesting the strain isn't transferrable to mammals.

The Australians' research was detailed in the latest issue of the journal American Society for Microbiology.