The Philippines has reported an outbreak of highly pathogenic H5N1 bird flu among backyard birds in its Oriental Mindoro province, the World Organisation for Animal Health said on Friday.

That came as Australia confirmed the first case of the deadly H5N1 virus in a local seabird, raising concerns that the disease is beginning to spread more widely after it landed in the country last month.

The spread of avian influenza, commonly called bird flu, has raised concerns among governments and the poultry industry after it ravaged flocks around the world in recent years, disrupting supply, fuelling higher food prices and raising the risk of human transmission.

The Philippines case was detected in a flock of 39 poultry in the town of Capalan, the Paris-based WOAH said, citing a report from the the country's officials. All birds were culled as a precaution.

The Australian finding, confirmed through laboratory testing by Australia's national science agency, involved a greater crested tern found in the South Australian coastal town of Robe, Agriculture Minister Julie Collins said.

It is the first confirmed infection in a mainland Australian seabird, with all other cases being found in migratory seabirds.

It brings the total number of positive detections in the country to 12, after authorities on Friday also confirmed two additional infections in South Australia and one in Western Australia.

Collins said the development was "concerning" but not unexpected, adding that there was still no evidence of mass mortalities or spread to other animal populations and the poultry or agriculture sector.

"Our scientists are undertaking further work to establish the potential pathway that resulted in the Australian seabird's infection," she said.

"What we do know is that this is a coastal seabird that has an overlapping coastal range with migratory seabirds that have previously tested positive for H5."

The virus spreading to a local seabird was "very bad news," said Hamish McCallum, an infectious diseases ecologist at Griffith University.

"It's likely that this will be the beginning of many more cases," he said.

New South Wales was the country's third state to detect H5N1, after a migratory seabird in the Mid North Coast tested positive this month.

The virulent strain of bird flu has spread through wild bird and mammal populations since 2021, killing millions, infecting poultry and dairy farms and even some farmworkers.

Australia in June became the final continent to confirm a mainland-based case of H5N1, although the virus had been detected in late 2025 on the sub-Antarctic territory of Heard Island, about 4,100 kilometres from continental Australia. (Reuters)



Edited by Thomas McAlinden