H5N1 bird flu reaches Victoria as local transmission spreads

Australia’s battle against the deadly H5N1 bird flu has escalated, with Victoria confirming its first case of the highly virulent strain on Thursday and authorities acknowledging that local transmission is now occurring among birds in South Australia. The developments mark a critical shift for the last continent to detect the virus, prompting warnings of increased wildlife deaths.

First case in Victoria and rising detections

The Victorian case was detected in a greater crested tern in the coastal town of Portland. Meanwhile, South Australia reported 13 new suspected detections in the same species on Thursday, including five at Seal Bay on Kangaroo Island, home to a significant population of endangered Australian sea lions. If confirmed, Australia’s total cases would reach 41.

Federal Agriculture Minister Julie Collins stated on Wednesday that the Consultative Committee on Emergency Animal Diseases had agreed that “some local transmission has occurred between a number of greater crested terns that are resident in South Australia.” This is the first evidence of the virus spreading within Australia rather than being introduced by migratory birds.

‘A shift in the situation’

Collins described the development as “very disappointing but not unexpected,” noting that Australia was the last continent to detect H5 bird flu. Chief Veterinary Officer Dr Beth Cookson said genetic sequencing links all confirmed cases to subantarctic strains. South Australian Primary Industries Minister Clare Scriven echoed the sentiment: “We knew that eventually when bird flu arrived in Australia it would spread. It has spread on every other continent around the globe.”

Authorities stress that the risk to human health remains low, and no cases have been reported in poultry or agricultural industries.

Threat to endangered marine mammals

Conservationists are particularly alarmed for the Australian sea lion population at Kangaroo Island. About 80% of the species resides in South Australia, with numbers having declined by 60% over four decades to approximately 12,000 individuals. Alexia Wellbelove, campaigns director at the Australian Marine Conservation Society, warned of potential devastation. “In South America, this virus killed 30,000 sea lion pups in just six months following transmission from birds to marine mammals,” she said. “On our own Heard Island, it killed more than 13,000 elephant seal pups in a single season. We now have to face the very real possibility of similar devastation here at home, in a species already teetering on the edge.”

What comes next

With local transmission now confirmed, authorities expect to see “increased evidence and deaths of wildlife.” Surveillance efforts are being ramped up, particularly around vulnerable colonies. The coming weeks will be crucial in determining whether the outbreak can be contained or whether it follows the devastating patterns seen on other continents. As Australia confronts this new phase, the focus remains on protecting both wildlife and the agricultural sector from a virus that has already caused catastrophic losses globally.