'Bad luck' for Australia's bird flu epicentre, but worse is to come

'Bad luck' for Australia's bird flu epicentre, but worse is to come Sat 8 Aug 2026 at 9:15am South Australia has been a victim of bad luck, having borne the brunt of H5 bird flu's arrival to Australia, the state's chief veterinary officer says. To date, SA accounts for more than three quarters of Australia's confirmed bird flu cases. That figure did not include a "mass mortality" event of an estimated 80 birds near Cape Jaffa in late July. "Unfortunately, we were just unlucky to be the first place where this did spread into our resident birds," SA's chief veterinary officer Dr Skye Fruean told ABC News Stateline. Authorities across the country are tightening biosecurity and monitoring captive bird populations, with the Royal Adelaide Show confirming birds competitions will not be held in September and Victoria locking down poultry flocks. But experts warn the spread is unlikely to remain confined to coastlines and could penetrate inland Australia. Australia has been waiting for this arrival for years The H5N1 variant has spread on every other continent of the planet, including Antarctica, since it was discovered in Chinese geese in 1996. Authorities outside Australia have attempted to protect their poultry from wild birds landing near them or sharing water sources to prevent spillovers, which occur when the disease is transmitted from one population to another — such as from wild to domestic birds, or from birds to mammals. When spillovers occur, the only available action is "depopulation" — or culling — entire infected flocks, sometimes numbering thousands of birds, and imposing quarantine and containment areas around farms. "Bird flu is a disease that they [farmers] have been concerned about for decades," Dr Fruean said. "While it's awful to watch, it's allowed us time to prepare to come here. "Certainly, the poultry industry has very much been at the forefront of that preparedness." Though no deadly spillovers from wild birds have occurred in South Australia, H5N1's path is following similar beats to the international experience. From the coast and beyond? In South America, the disease spread from birds, infecting and killing thousands of sea lions and elephant seals since 2022. Australia's first H5N1 detection was among elephant seals on its remote Heard Island territory about 3,000 kilometres south-west of Perth in November. Efforts are now being made to secure and protect endangered sea mammal herds in places like Kangaroo Island, which has recorded positive cases in birds. South Australia's cases have mostly been in coastal areas, including in the south-east region and Kangaroo Island. That was until a confirmed case was recorded at Monarto — 20 kilometres inland from Lake Alexandrina. Cases have also been largely in greater crested tern species, though migratory giant petrels and silver gulls (seagulls) have also been infected. Chris Purnell, who is Birdlife Australia's manager of wetland and migratory shorebirds, said ducks would most likely be the culprit of any future spread inland. "Ducks are going to be one of the major vectors because of their ability to stay alive and carry the disease further [inland]," Dr Purnell said. "The disease survives longer in fresh water is the other factor. "They're defecating in the water, they're feeding in the water and lots of other birds are feeding in the same water column where the disease is surviving. That's the issue." Dr Fruean, who oversees SA's bird flu response, said the rapid increase in confirmed cases in the state was "not unexpected". "As soon as we had that evidence of local transmission in resident birds here in South Australia we knew it was going to continue to spread and that is what we're now seeing," she said. "We would expect the spread to continue, [but] unfortunately I can't tell you how quickly that will happen." Low human concern, but fears for other animals H5 bird flu is an influenza virus that can infect humans, but this has been relatively rare. Fewer than 1,000 people globally have contracted the disease since it was first identified three decades ago, and usually biosecurity or farm workers exposed to sick or dead animals were at greatest risk. "Only if you're in really close contact with animals that have really high amounts of virus are you able to get infected with this H5 virus," La Trobe University viral immunologist Emma Grant said. "This has happened in people who work in poultry, this has been seen in live poultry markets in various parts of the world, and in the US in the dairy industry." Those US cattle have been infected by the same H5N1 "clade" as the one now in Australia, though a different genotype. "Could that occur in Australia? It could if you've got collections of birds near free-ranging cattle," said Wayne Boardman, a wildlife veterinarian and expert in wildlife health at Adelaide University. "You can't dismiss it, that's for sure — it's probably less of a serious consequence, but it seems like many mammal species can get affected by it." But it's less about the cattle for experts like Dr Boardman, who are most concerned about native animals. "We've got scavenging birds like white-bellied sea eagles … wedge-tailed eagles, or other species that might pick up carrion," Dr Boardman said. "But also the mammalian carnivores as well, like quolls, Tasmanian devils, we've got no idea how susceptible they might be to the virus." What can we do? While the concern for inland spread and the spread into other animals like cows exists, experts say these are yet to be realised. They said there were still some actions from humans that could help. For Birdlife Australia's Chris Purnell, it is as simple as leaving birds alone. "It's just critically important to reduce any unnecessary disturbance to these birds that might pique their cortisol, get them moving," he said. "It not only disturbs them from the site but also reduces their immune response and increases the likelihood that they're going to shed more disease." For all the anticipation of H5N1's arrival, its early impact in South Australia has not been an easy one for communities. Sadly, as the international example has often shown, the worst is yet to come. "I think the Australian population will be utterly devastated," Dr Boardman said. "Particularly if we go into iconic endangered species like glossy black cockatoo, for example, or the plains wanderer or the orange-bellied parrot … if it got into Australian sealions, which is an iconic South Australian species. "If you see the virus getting into these populations, then people are going to be thinking 'is there any more we can do?'"