H5N1 bird flu spreads to the Philippines and Australia
WOAH confirms an outbreak in Philippine poultry, prompting the culling of 39 birds, while Australia records its first case in a native seabird
Australia has recorded its first H5N1 bird flu infection in a local seabird, while the Philippines has reported a separate outbreak among backyard poultry, adding to concern over the virus’s continued spread across the Asia-Pacific region.
Laboratory tests confirmed H5N1 in a greater crested tern found in the coastal town of Robe in South Australia, making it the first mainland Australian seabird native to the country to test positive. Previous detections had involved migratory seabirds.
On the same day, the World Organisation for Animal Health reported that highly pathogenic H5N1 had been detected in a backyard flock in Capalan, Oriental Mindoro province, in the Philippines. The flock comprised 39 birds, all of which were culled as a precaution.
Local seabird case raises concern in Australia
Australia’s national science agency confirmed the virus in the greater crested tern, Agriculture Minister Julie Collins announced.
The finding brought the country’s total number of confirmed H5N1 detections to 12 after authorities also reported two additional cases in South Australia and one in Western Australia.
Collins described the latest case as concerning but not unexpected. She noted that authorities had found no evidence of mass bird deaths or transmission into other animal populations, poultry farms or the wider agricultural sector.
Scientists are investigating how the local seabird became infected. The species shares parts of its coastal range with migratory seabirds that had previously tested positive for H5 viruses, providing a possible route of exposure.
Hamish McCallum, an infectious-disease ecologist at Griffith University, described the infection of a local seabird as a serious development and warned that more cases were likely to follow.
Fur seal tests negative
Authorities also tested a dead juvenile fur seal found on the Central Coast of New South Wales, but the result was negative for H5N1.
New South Wales had earlier become the third Australian state to detect the virus after a migratory seabird on the Mid North Coast tested positive.
Australia confirmed its first mainland-based H5N1 case in June, becoming the last continent to record the strain on its mainland. The virus had previously been detected in late 2025 on Heard Island, a sub-Antarctic Australian territory about 4,100 kilometres from the continent.
Scientists believe H5N1 has killed about 13,000 seal pups on Heard Island.
Philippine outbreak contained through culling
In the Philippines, authorities reported the Oriental Mindoro outbreak to the World Organisation for Animal Health.
The virus was found among backyard poultry rather than at a large commercial farm. All 39 birds in the affected flock were destroyed to contain the outbreak and reduce the risk of further transmission.
No further information was provided on the species of poultry involved or whether infections had been detected beyond the affected flock.
Virus continues to challenge poultry and wildlife
Highly pathogenic avian influenza has spread extensively through wild-bird and mammal populations since 2021.
The virus has killed millions of animals, caused outbreaks on poultry and dairy farms and infected some agricultural workers.
Its continued spread has placed governments and the poultry industry on alert because outbreaks can disrupt food supplies, raise prices and increase concern about possible transmission to humans.
The latest detections highlight two different risks: transmission from migratory birds into native wildlife in Australia and infection among small backyard poultry flocks in the Philippines.
