Queensland became Australia’s fourth state to confirm a case of H5N1 bird flu ​after authorities said on Saturday that a ‌migratory seabird tested positive for the highly pathogenic virus.

Australia was the final continent to confirm a mainland case ​of H5N1 when the disease arrived in ​June, although it had been detected in ⁠late 2025 on the sub-Antarctic territory of Heard ​Island, about 4,100 km (2,600 miles) from continental Australia.

Eighteen ​infections have now been confirmed across four states, including in the dead petrel found by Queensland park rangers ​at Moreton Island, a wilderness area about ​40km (24 miles) by ferry from state capital Brisbane.

“There remain no ‌detections ⁠in poultry, nor evidence of large-scale deaths in any animals in Queensland,” the authorities said in a statement, adding that the risk to ​human health remained ​low.

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.

Earlier this month, Australia’s centre-left government confirmed the first case of ⁠the ​virus in a local seabird, ​raising concerns the disease was starting to spread more widely.