Listen to this story.

Brown skua

Lori-Ann Shibish, Esperance Wildlife Hospital and Sanctuary

Australia's first recorded case of an especially virulent form of highly pathogenic avian influenza was confirmed in this brown skua, which died shortly after it was taken to a wildlife sanctuary by a veterinarian who found it on a remote beach.

A highly virulent form of avian influenza that has devastated bird and some mammal populations across multiple continents has gone truly global, having been detected in Australia for the first time.

Its discovery there — by a veterinarian who, by chance, picked up a sick seabird while she was walking on a beach — has prompted at least one large commercial poultry operator to lock down some of its farms. Concerns also have been raised for the safety of vulnerable and endangered species like Australian sea lions, black swans, little penguins, orange-bellied parrots and Tasmanian devils.

Australia until now was the only continent on Earth on which the aggressive form of highly pathogenic avian influenza (HPAI) — known technically as H5N1 clade 2.3.4.4b — had not been seen.

The Australian government announced on the weekend that the virus had been detected in a brown skua, a type of migratory seabird, found on a remote beach near the town of Esperance on the southern coast of the state of Western Australia. A second migratory bird found nearby, a giant petrel, was confirmed positive for the virus on Monday.

Dr. Alex Hockton of Swans Veterinary Services, a practice in Esperance, said in an interview that his colleague, Dr. Toni Howlett, found the sickly brown skua on June 14 while on a Sunday hike in the Cape Le Grand National Park.

"It was a bit coincidental that it was a vet that found it," Hockton said. "We see heaps of seabirds here for all sorts of things, and she was keen to do the best for the bird and brought it back to town with her."

Wild birds in the area often suffer from exhaustion or botulism, Hockton said. But when the skua, which was taken to a local wildlife center, perished overnight, suspicions arose that it could have had HPAI. Subsequent testing was positive for the virus.

The second bird, the giant petrel, was brought to the Esperance clinic by a member of the public before the test results for the skua came in. But out of an abundance of caution, Hockton arranged for the petrel, which also had died quickly, to be tested for HPAI, too.

Neither bird, he said, had neurological, respiratory or gastrointestinal issues — clinical signs often associated with HPAI. Rather, they just displayed signs of exhaustion and dehydration.

"The index of suspicion for that second case was mostly based on the birds' distribution — the fact that two birds were found in a similar location at the same time," he said. "And HPAI has been on our radar and talked about a fair bit, especially since it was detected on Heard Island."

The virus was found last August on Heard Island, located about 2,500 miles off Australia's southern coast. On the island, the pathogen has killed thousands of elephant seals and hundreds of king penguins. It was widely expected to reach Australia at some point, according to the agriculture minister, Julia Collins, who said the federal government had invested more than AU$100 million (US$70 million) in recent years to prepare for an outbreak.

"We have looked at what has happened overseas, [and] we have learnt from that, which is why we have invested early," she said at a press conference.

Still, the Australian Veterinary Association said the veterinary profession isn't adequately prepared to combat the virus's potential spread. It called on the government to immediately commit AU$7.5 million (US$5.2 million) over four years for a pilot program that would compensate veterinarians who care for sick animals brought into clinics by the public.

"We cannot ask a depleted and exhausted workforce to carry the weight of the nation's biosecurity defence indefinitely without urgent investment," the AVA's president, Dr. Diana Barker, said in a press release. "A response to an event like this draws on the very veterinarians who are already in critically short supply in the bush, including in the Western Australian community where the first detections were made."

The number of birds infected in Australia is unknown, as is whether the virus will spread beyond the country's remote southwestern coast.

Dr. Beth Cookson, Australia's chief veterinary officer, noted that in other countries, detections sometimes remained contained to a small number of birds, with no interspecies spread.

"But over time, what we've seen in many other continents across the globe, is that this may not be a sole introduction, because they are birds that are moving around as part of their natural cycles and, over time, if we continue to have introductions, then those opportunities for spillover become increased," she said in the same press conference as Collins.

The form of the virus behind the current panzootic — which is a pandemic among nonhuman animals — was first detected in Europe in 2020. It subsequently spread to Africa and Asia, then to the United States, South America and Antarctica. In the U.S. alone, it has led to the culling of more than 206 million birds in commercial and backyard poultry operations.

In Australia, the country's biggest poultry producer, Ingham, said it has ceased all nonessential access to its farms in Western Australia as a precaution. The company also has requested government permission to keep its free-range chickens indoors.

Petrel

Lori-Ann Shibish, Esperance Wildlife Hospital and Sanctuary

This giant petrel is the second of two birds found in Australia to be infected with HPAI. It was taken to a veterinary clinic by a member of the public and died soon afterward.

Among wild animals, the iconic Tasmanian devil, a critically endangered scavenging mammal, is particularly vulnerable to HPAI because it feeds on animal carcasses that, in the event of a spread, could harbor the virus, Fiona Fraser, Australia's threatened-species commissioner, told the press conference. Work to protect that and other particularly vulnerable species involves removing other threats to their survival, such as weeds, foxes and feral cats. "The most important thing we can do for our native species is to actually take efforts to build their resilience to this disease in the wild, because we can't stop the disease itself," Fraser said.

Hockton said that although the Esperance clinic hasn't seen more suspected cases, it's receiving a lot of phone calls about dead birds. The clinic is directing people to report fatalities to an emergency hotline set up by the Australian government. "Our advice to the public is, 'Do not touch or approach sick or dead birds or other wildlife, and call the Emergency Animal Disease Hotline,' " he said.

While finding Australia's first reported cases of HPAI came as a shock, Hockton said, the clinic's veterinarians knew Esperance was a potential entry point for the virus, given that high winds common in the area could blow migratory seabirds off course and onto the mainland.

"We hope that the weather systems may have generated some isolated cases, that they haven't interacted with other animals and the problem is not going to continue," he said. "But there's certainly a risk of seeing more cases."