H1N1 virus found in marine mammals for first time

U.S. researchers said Wednesday they have detected for the first time the H1N1 virus in elephant seals off the coast of central California.

The H1N1 strain is the same one that emerged in humans in 2009 and it's the first report of that flu strain in any marine mammal, researchers at the University of California, Davis reported in the journal PLOS ONE.

"We thought we might find influenza viruses, which have been found before in marine mammals, but we did not expect to find pandemic H1N1," said Tracey Goldstein, lead author of the study. " This shows influenza viruses can move among species."

Between 2009 and 2011, the researchers tested nasal swabs from more than 900 marine mammals from 10 different species off the Pacific Coast from Alaska to California. They detected H1N1 infection in two elephant seals and antibodies to the virus in an additional 28 elephant seals, indicating more widespread exposure.

Neither infected seal appeared to be ill, indicating marine mammals may be infected without showing clinical signs of illness.

The researchers said the seals tested negative before they went to sea in early 2010 but they tested positive when they returned from sea in spring 2010. They suspected that exposure occurred in the seals before they reached land, either while at sea or upon entering the near-shore environment.

The researchers advised people who handle marine mammals, such as veterinarians and animal workers, to wear personal protective gear in a bid to avoid the possibility of infection.