Seal's death from H5N1 marks Australia's first mammal infection

A fur seal found dead on the coast of South Australia has tested positive for the highly pathogenic H5N1 avian influenza virus, marking the first time a mammal in Australia has contracted the disease. The seal, a long-nosed fur seal, was discovered deceased on August 20 in Beachport, a coastal town in South Australia. Authorities suspect the animal may have become infected through contact with infected wild birds or by sharing an environment with them.

Australian Agriculture Minister Julie Collins stated that the seal's infection was likely linked to contact with infected wild birds or a shared environment. She warned that H5 avian influenza is difficult to contain once it enters the natural environment and that more marine mammal infections could occur as the number of dead wild birds increases. This case follows multiple reports of mass wild bird deaths in Australia during August, including over 1,000 greater crested terns on an island off the coast of South Australia.

The Australian government has identified the long-nosed fur seal and the endangered Australian sea lion as high-risk mammals for H5 virus infection. Jack Gough, CEO of the Invasive Species Council, cautioned that a spread to Australian sea lion populations could have severe, even "extinction-level" ecological consequences. The South Australian government also confirmed that a little penguin on Kangaroo Island tested positive for H5 avian influenza and is considering experimental vaccines to protect mammals, though these are not yet approved.

Despite these concerns, Australian officials maintain that the risk to humans remains low, and the virus has not entered the country's domestic poultry or agricultural systems. The public is advised to avoid contact with sick or dead wild birds and to report any such findings to the relevant authorities.