Australia expands H5N1 surveillance after first mainland bird flu cases

Australia has intensified wildlife surveillance and laboratory testing after confirming the country’s first mainland cases of highly pathogenic H5N1 avian influenza in two migratory seabirds found near Esperance in Western Australia. By June 24, 2026, authorities were testing additional dead or unwell birds in Western Australia and South Australia, including specimens discovered near Fowlers Bay, more than 1,200 kilometres east of the original detections. No infection had been identified in commercial poultry, livestock or people, and officials said there was no evidence of widespread mortality among Australian wildlife. The confirmed arrival nevertheless ends Australia’s position as the only continent without a mainland detection of the globally circulating H5N1 strain and begins a critical test of the country’s biosecurity, wildlife protection and agricultural response systems.

The first confirmed mainland case involved a brown skua found sick in an isolated coastal area near Esperance. A northern giant petrel discovered in the same region subsequently became the second confirmed case. Both are migratory seabirds capable of travelling long distances across the Southern Ocean, supporting the assessment that infected wildlife carried the virus to the Australian mainland rather than the disease emerging within a poultry production system.

Australia had prepared for the arrival of H5N1 after the virus spread through wild birds, poultry and some mammal populations across much of the world. The strain was detected in late 2025 on Heard Island, a remote Australian sub-Antarctic territory, but had not previously been confirmed on the mainland. The immediate objective is to determine whether the two Esperance cases represent isolated arrivals or the beginning of sustained circulation among Australian wildlife.

What did Australia confirm near Esperance and why are the two H5N1 cases significant?

Laboratory testing confirmed highly pathogenic H5 avian influenza in the brown skua after the bird was found near Esperance in June 2026. The testing was conducted through Australia’s national animal-disease laboratory system, including the Commonwealth Scientific and Industrial Research Organisation’s Australian Centre for Disease Preparedness. The northern giant petrel found in the same coastal region later tested positive, bringing the confirmed mainland total to two.

Australian Minister for Agriculture, Fisheries and Forestry Julie Collins said the detections were not unexpected given the virus’s international spread, but she stressed that the development represented the first confirmation on mainland Australia. Australian Chief Veterinary Officer Beth Cookson said there was no evidence at that stage of infection in poultry or agricultural production systems and no confirmed mass-mortality event among wild birds.

The distinction between isolated infected birds and an established wildlife outbreak is crucial. Migratory seabirds can arrive infected, die and produce no continuing transmission. A more serious scenario would involve the virus spreading into resident seabirds, waterbirds, marine mammals or species that regularly interact with poultry farms and backyard flocks.

Determining which scenario is developing requires more than testing the original birds. Authorities must examine surrounding wildlife, identify unusual deaths, compare virus samples and monitor locations connected through bird movement. The geographical spread of new reports will help indicate whether the Esperance detections remain localised or form part of a wider coastal incursion.

The cases are significant because Australia’s geographical isolation and migratory patterns had delayed the mainland arrival of the H5N1 strain that has circulated internationally. That delay gave governments, conservation agencies and agricultural producers additional preparation time, but it did not provide permanent protection against a virus carried by wildlife across national borders.

Why are South Australia and Western Australia testing more dead seabirds along remote coastlines?

Testing expanded after two dead sub-Antarctic seabirds and a pelican were found near Fowlers Bay in South Australia on June 22. Fowlers Bay lies more than 1,200 kilometres east of Esperance, making the specimens important to understanding whether infected migratory birds have reached multiple points along Australia’s southern coastline.

South Australian Minister for Primary Industries and Regional Development Clare Scriven said laboratory results could take several days. South Australian authorities had not confirmed any H5N1 case by June 24, and the birds’ deaths could have causes unrelated to avian influenza. The specimens were therefore being treated as suspected cases rather than evidence that the virus had already spread into South Australia.

Authorities began ground-based surveillance and drone surveys at Australian sea lion breeding locations along South Australia’s western and far-western coasts. Testing frequency was also increased in areas assessed as having a higher risk of wildlife exposure. The use of drones allows monitoring teams to examine colonies and remote beaches while reducing unnecessary human contact with potentially infected animals.

Western Australian authorities were also investigating reports beyond the first detection area. Eleven samples had been submitted for testing after officials received 94 reports of dead or unwell birds over three days. Two birds discovered far from the original cases were among those being examined, although authorities said there was no evidence of wider transmission at that stage.

The reports demonstrate why community surveillance is an important part of the response. Australia’s coastline is too extensive for government teams to inspect continuously, meaning members of the public, wildlife carers, fishing communities and tourism operators can provide early warnings by reporting unusual sickness or death.

Officials have advised people not to touch dead or visibly sick birds. Handling infected wildlife without protective equipment can expose a person to the virus and can transfer contaminated material to clothing, footwear, vehicles, pets or domestic birds.

Could Australia’s first mainland H5N1 cases spread into commercial poultry and affect food supplies?

No H5N1 infection had been confirmed in Australian commercial poultry by June 24. The initial detections occurred in wild migratory seabirds, and there was no evidence that the virus had entered chicken meat, egg or breeding operations. Australian authorities nevertheless placed strong emphasis on protecting poultry because outbreaks in farmed birds can spread rapidly and require extensive containment measures.

Australia’s largest poultry producer, Inghams Group Limited, activated a complete precautionary biosecurity lockdown across its farms and processing locations in Western Australia. The company said there had been no detection within its operations or supply chain. The response was intended to limit unnecessary movement and reduce opportunities for contact between production systems, people, equipment and potentially infected wildlife.

Farm protection measures include keeping wild birds away from poultry housing, feed and water; controlling access by workers and visitors; cleaning equipment and vehicles; monitoring flock health; and reporting unexplained mortality or sudden falls in egg production. Water sources accessible to wild birds are a particular concern because infected birds can contaminate shared environments through secretions and faecal material.

If the virus enters a commercial flock, authorities may impose movement controls, quarantine premises and destroy infected or exposed birds to stop transmission. Such measures have affected poultry and egg supplies in other countries, creating financial losses for farmers and contributing to food-price volatility.

The World Organisation for Animal Health has warned that highly pathogenic avian influenza can cause the death or culling of entire poultry flocks and disrupt agricultural production, rural livelihoods and international trade. More than 13 million poultry birds died or were culled globally during February 2026 alone as countries responded to reported outbreaks.

Australia has previously experienced outbreaks caused by highly pathogenic H7 avian influenza strains, but the globally dominant H5N1 strain presents a different challenge because of its extensive circulation in wild birds. Poultry biosecurity can reduce contact and limit farm-to-farm transmission, but it cannot prevent infected migratory wildlife from reaching Australian territory.

Why could H5N1 create an ecological threat for Australian birds and marine mammals?

The greatest immediate uncertainty concerns Australia’s native wildlife. H5N1 has caused major mortality among seabirds, waterbirds and marine mammals overseas, including species that gather in dense breeding colonies where infection can move quickly between animals. The virus has also reached remote islands and polar environments once considered partly protected by geographical isolation.

Australia has species with small, geographically concentrated or already declining populations. A severe outbreak in one breeding colony could therefore have consequences beyond the loss of individual animals. It could damage an entire regional population, interrupt breeding and slow recovery for endangered species.

Marine mammals are also being monitored because H5N1 has infected seals and sea lions in other parts of the world. Fowlers Bay and nearby coastal environments are connected to important Australian sea lion habitats, which explains the decision to conduct surveillance at breeding sites while the South Australian bird samples are tested.

Wildlife agencies face a different problem from poultry producers. Commercial farms can restrict access, separate flocks and disinfect buildings. Wild animals move freely across beaches, islands, wetlands and oceans, making conventional containment difficult or impossible after widespread transmission begins.

Australia has invested in species-specific planning, surveillance, wildlife vaccination programmes and emergency simulations. Federal preparations include more than A$100 million in H5 bird flu readiness, with additional funding announced in June 2026 to strengthen protection for species considered particularly vulnerable.

The effectiveness of those plans will depend on early detection and prioritisation. Authorities cannot vaccinate or physically protect every wild animal, so they must identify species and colonies where intervention could prevent extinction, protect breeding populations or reduce transmission into other ecosystems.

Does the arrival of H5N1 in Australian seabirds create an immediate threat to people?

The current risk to the general public remains low because human H5N1 infections are rare and are usually associated with close, unprotected contact with infected animals or contaminated environments. Sustained transmission between people has not been reported, and the virus does not currently spread efficiently from person to person.

Australia had not reported a human infection connected to the Esperance seabirds by June 24. The confirmed cases involved wild birds, and authorities had not identified infection in poultry, livestock or food-production systems. The public-health response is therefore focused on preventing exposure rather than responding to community transmission.

People at greater occupational risk include veterinarians, wildlife officers, laboratory workers, poultry employees and others who may handle infected birds or enter contaminated locations. Protective clothing, gloves, eye protection, respiratory equipment and controlled sample-handling procedures can reduce that exposure.

Members of the public should avoid touching sick or dead birds and should prevent children and pets from approaching carcasses. Reports should be made through state wildlife or emergency animal-disease channels so trained personnel can assess and collect specimens safely.

H5N1 is not considered a foodborne threat when poultry and eggs are handled hygienically and cooked properly. The World Health Organization states that there is no evidence that people acquire avian influenza through properly prepared and cooked poultry meat or eggs.

The low current public-health risk does not remove the need for continued monitoring. Influenza viruses evolve, and repeated infection across bird and mammal populations creates opportunities for genetic change. Health and veterinary institutions therefore use a One Health approach that connects wildlife surveillance, agricultural testing and human influenza monitoring.

Why did mainland Australia remain free of H5N1 for so long and what has now changed?

Australia’s isolation from major continental landmasses and the movement patterns of its wild birds helped delay H5N1’s arrival. Many Australian waterbirds remain within the region rather than migrating through areas experiencing large outbreaks, reducing some of the pathways that carried the virus between Europe, Asia and the Americas.

Seabirds that travel through sub-Antarctic and Southern Ocean environments presented a different route. The detection of H5N1 on Heard Island in late 2025 showed that the virus had reached an Australian external territory and had moved closer to wildlife pathways connected with the mainland.

The infected brown skua and northern giant petrel near Esperance are consistent with that pathway. Both species can move across large marine areas, making it possible for infection acquired elsewhere to be transported to southern Australia without passing through conventional border-control systems.

Biosecurity screening is highly effective against diseases carried through travellers, cargo, livestock or agricultural products, but it cannot inspect migratory wildlife before arrival. Australia’s strategy therefore depended on preparation, rapid reporting and laboratory confirmation once the virus crossed the natural barrier.

The first mainland detections do not prove that H5N1 has become established in Australia. Establishment would involve continuing transmission within local wildlife or domestic animals rather than isolated cases imported through migration. Genetic analysis, surveillance results and the discovery of additional infected species will help authorities determine whether that threshold has been crossed.

The arrival does mean that Australia has entered a new phase. Officials are no longer preparing solely for a hypothetical incursion. They are managing confirmed cases while attempting to preserve the opportunity to contain, slow or geographically limit the virus.

What happens next as Australia tests more birds and protects wildlife and farms?

The first priority is to complete testing of birds collected in Western Australia and South Australia. Negative results would support the possibility that the Esperance detections remain limited, while additional positives across distant locations would suggest a wider migratory introduction or early coastal spread.

Authorities will continue monitoring beaches, wetlands, seabird colonies and marine-mammal breeding sites. Reports of clustered deaths, neurological symptoms or unusual behaviour will receive particular attention because highly pathogenic avian influenza can cause sudden mortality and severe neurological or respiratory illness in affected wildlife.

Commercial poultry producers are likely to maintain heightened biosecurity until authorities better understand the scale of the incursion. The absence of farm infections is reassuring, but each new wildlife detection could alter the assessment of where poultry operations face the greatest exposure.

Public-health agencies will monitor people with direct contact with infected animals. Human testing would become relevant when an exposed person develops compatible symptoms, particularly after handling birds without appropriate protection.

The central question is not whether Australia can prevent every infected migratory bird from arriving. That is unlikely to be possible. The test is whether surveillance can identify transmission early enough to protect poultry, reduce human exposure and preserve vulnerable wildlife populations.

Australia’s preparation has bought valuable response capacity, but the next several weeks will reveal whether the first two mainland H5N1 cases remain isolated warnings or mark the beginning of a larger animal-health and conservation emergency.

What are the key takeaways from Australia’s first mainland H5N1 bird flu detections?

• Australia confirmed its first two mainland cases of highly pathogenic H5N1 avian influenza in a brown skua and a northern giant petrel found near Esperance in Western Australia during June 2026.
• Additional birds are being tested in Western Australia and South Australia, including dead seabirds and a pelican discovered near Fowlers Bay, more than 1,200 kilometres east of the original detections.
• No H5N1 infection had been confirmed in commercial poultry, livestock or people by June 24, and authorities said there was no evidence of widespread wildlife mortality or established transmission.
• Western Australian authorities submitted 11 samples for testing after receiving 94 reports of dead or unwell birds within three days, while surveillance continued in areas beyond the original Esperance site.
• South Australian agencies deployed ground teams and drones around sea lion breeding locations and increased testing in high-risk coastal areas because H5N1 has infected marine mammals during overseas outbreaks.
• Inghams Group Limited activated a precautionary biosecurity lockdown across its Western Australian farms and processing sites, while confirming that the virus had not been detected in its operations or supply chain.
• Human infection remains rare and sustained person-to-person transmission has not been reported, but people should avoid touching sick or dead birds because direct animal exposure creates the greatest recognised risk.
• The confirmed mainland arrival does not establish that H5N1 is circulating permanently in Australia, and laboratory testing, genetic analysis and continuing wildlife surveillance will determine whether further transmission has occurred.