Australia H5N1: SA Confirms H5N1 in Red Fox and Dolphin - Govt. Will Withdraw Research Team From Macquarie Island

 

(ttls as of 8/27)

#19,313

Not unexpectedly, the red fox recovered from an Adelaide suburb earlier this week has been confirmed positive for the H5N1 virus, making it the first land mammal infected on the Australian mainland.  

28 August 2026

Attributable to Australian Chief Veterinary Officer, Dr Beth Cookson:

Testing at CSIRO’s Australian Centre for Disease Preparedness (ACDP) has confirmed H5 high pathogenicity avian influenza (bird flu) in a red fox, found at Osborne in metropolitan Adelaide.

This marks the third detection of H5 bird flu in a mammal species in Australia, and the first in a land mammal.

There is currently no evidence of mammal-to-mammal transmission associated with H5 bird flu in Australia.

On other continents, infection has been documented in a wide range of terrestrial carnivores, particularly species that scavenge carcasses (including red foxes). In wild terrestrial carnivores these detections are believed to be isolated spillover events from birds.

Although this is a concerning development, it is not unexpected given that H5 bird flu has been detected in other wildlife in areas where there are high levels of infection in wild birds.

This detection in a fox is a good reminder that people and their pets should avoid sick or dead wildlife.

There remain no detections in poultry or in our agricultural production system.

The risk to human health remains low.

From 12 August 2026, we have changed how we report on H5 bird flu detections. Reporting will be based on events, rather than individual detections. See birdflu.gov.au for the latest information.

Today South Australia has announced the nation's first confirmed infection in a Dolphin, and SA will now accept local testing when determining positive cases.

H5 bird flu testing update 28 August

Friday 28 August 2026 

There are 46 new confirmed H5 bird flu events in South Australia since yesterday’s update, including Australia’s first detection in a dolphin.

The increase in cases reported today reflects a change to the way H5 bird flu cases are confirmed in South Australia, helping to provide faster results and more timely reporting.

Under the updated approach to reporting, cases can now be confirmed when laboratory testing in Adelaide detects the H5 bird flu virus. Previously, most samples were routinely sent to the ACDP for additional testing before a case could be confirmed.

The change, which is supported through nationally agreed protocols, reduces delays and allows specialist national laboratory resources to be focused on more complex or unusual cases.

Samples will still be referred to ACDP where further analysis is required, such as when results are unclear or where additional information is needed to support the investigation. This means all of our previously suspect cases are now confirmed, and additional positive cases have been confirmed based on SA-based laboratory testing.

The new positive events include a common dolphin at Goolwa, which has been referred to ACDP for further analysis, and a red fox at Osborne, which was previously reported as a suspect event.

While the detection in the common dolphin is a new development in Australia, there is evidence of dolphins and porpoises catching H5 bird flu overseas. Dolphins would not commonly eat birds but it is not unusual for them to sometimes interact.

        (Continue . . . )
 

Last October we learned of the mass mortality event of birds and marine mammals on the uninhabited Heard Island, nearly 4,000 km south-west of Perth. 

Heard & McDonald Islands - Credit Wikipedia

While an expedition was sent to the island to collect samples, we didn't really learn about the size and scope of this event until the publication - earlier this summer - of Preprint: Mass mortality of southern elephant seals during multi-species outbreak of HPAI H5N1 on sub-Antarctic Heard Island.

 Drone surveys revealed mass mortality in southern elephant seals, with 8,573 pups (62%) recorded dead across Heard Island by the final surveys. Mortality increased at an average rate of 5.6% per day in a subset of harems, and the highest observed mortality in a harem was 97%. Based on the average (76%) mortality in the final surveys, total estimated pup mortality at Heard Island was 13,359 (from a total population of 17,364 pups), though this may be an underestimate as mortality was ongoing at this time. 

Positioned in the southwestern Pacific Ocean - roughly halfway between Australia and Antarctica - is another large colony of Elephant Seals on Macquarie Island where H5N1 is expected to arrive later this year.  

Unlike the uninhabited Heard Island, the Australian government maintains research station with roughly 24 personnel who live in close proximity to these marine mammals. 

Citing `psychosocial risks' to personnel who are stationed there, the DCCEEW has decided to temporarily extract all personnel from the research station. The unsaid bit is that - low risk or not -  the chances of environmental exposure in the midst of a mass mortality event is undoubtedly heightened. 

Expeditioners to be withdrawn from Macquarie Island research station

Media release 
28 August 2026


The Australian Government’s Antarctic Division has made the difficult decision to temporarily withdraw staff from Macquarie Island research station due to the psychosocial risk to expeditioners posed by a potential H5 avian influenza (bird flu) outbreak on the remote island.

The research station, where 24 expeditioners currently live and work, was established on the Southern Ocean island about 1,500km south-east of Tasmania in 1948.

While the risk to humans remains low, a significant mortality event during the upcoming seal breeding season could expose expeditioners to prolonged psychological stress and other workplace impacts.

The health, safety and wellbeing of expeditioners is the highest priority for the Australian Antarctic Division, making their withdrawal from Macquarie Island a necessary precaution. Sending a ship to extract our staff from Macquarie Island is a significant undertaking. An unplanned evacuation could take months or disrupt all our other stations. This is why we are taking a planned and deliberate approach ahead of a wildlife mortality event.

The situation at Macquarie Island is different to Australia’s Antarctic stations, where stringent H5 bird flu preparations can manage risks for expeditioners.

While H5 bird flu has not yet been detected on the island, it is home to large elephant seal populations close to station buildings – and expert assessments predict a high likelihood of a significant mortality event during the upcoming breeding season.

Elephant seals have proved particularly susceptible to H5 bird flu, with pup mortality rates of more than 90 per cent discovered in some colonies in the sub-Antarctic external territory of Heard Island and McDonald Islands.

Australia’s icebreaking research and supply vessel, RSV Nuyina, will travel to the island in early October to retrieve personnel and essential cargo.

The Australian Antarctic Division is currently working through steps to mitigate impacts for our international monitoring obligations, wildlife monitoring and infrastructure, and to best prepare the station for temporary closure.

Overseas experience shows few direct actions can be taken to mitigate the impacts of H5 bird flu on native species. Owing to the island’s remoteness and harsh conditions, active control measures for wildlife are not planned at this stage.

Fortunately, wildlife on Macquarie Island exists in a largely undisturbed state.

The territory is free of most invasive species that threaten native species and ecosystems commonly found in mainland Australia.

This follows significant investment and effort in previous years to eradicate rabbits, rats and mice, which has boosted resilience and increased chances of recovery among island seals.

(Continue . . . )

Japan MHLW Reports Unusually Early Start to the Fall Flu Season

 

#19,312

Even though it is still August - and the Southern Hemisphere's flu season is still ongoing -  Japan's Ministry of Health, Labour and Welfare today has announced an unusually early start to their fall flu season. 

(translated)

While primarily a fall/winter phenomenon, the Northern Hemisphere isn't entirely devoid of influenza in the summer. Hong Kong often reports both a winter and a summer flu season  and has been reporting elevated activity (mostly H1N1) since mid-summer.

Hong Kong's CHP also reported the following Mainland update in yesterday's weekly flu report:

In Chinese Mainland (week ending Aug 16, 2026), the percentage of specimens that tested positive for influenza in the southern provinces slightly increased, while that in the northern provinces remained low, with the rates at 18.6% and 2.1% in week 33, respectively. The proportion of influenza A(H3N2) among detections increased nationwide. In Macao (week ending Aug 15, 2026), the influenza positivity rate was 20.9%, which was higher than the alert level. Influenza A (H3) was predominating.

While Japan's flu season normally begins in November or December, last year it kicked off in early in early October, with the arrival of the drifted subclade K H3N2 virus. 

While it is too soon to even begin to guess about the severity - or longevity - of this year's flu season, Japan is urging its citizens to take prevention seriously.  The following (translated) excerpt comes from today's press release. 

[Basic Infection Control Measures] Effective ways to prevent infectious diseases, including influenza, are "handwashing" and "cough etiquette , including wearing a mask ."

 In particular, the risk of developing severe symptoms increases for the elderly and those with underlying medical conditions. When meeting with the elderly, going to the hospital, or gathering in large groups, please cooperate with infection control measures, including wearing a mask. 

[Situations where wearing a mask is effective] To prevent infection among the elderly and other people at high risk of severe illness, wearing a mask is recommended when visiting a medical institution or when visiting medical institutions or elderly care facilities where many elderly people and other people at high risk of severe illness are hospitalized or living . In addition, during influenza season, when people at high risk of severe illness go to crowded places, wearing a mask is an effective measure to protect themselves from infection. 

Attachment This outbreak is the second earliest since the Infectious Diseases Control Law was enacted in 1999, following 2009*, and last year...

 [Vaccination] The influenza vaccine is believed to have some effect in suppressing the onset of the disease and preventing severe illness, and is considered to be particularly effective for the elderly and those with underlying medical conditions, who are at high risk of developing severe illness if they contract the disease. The following people are eligible for routine vaccination: ÿ People aged 65 and over ÿ People aged 60-64 with impaired heart, kidney, or respiratory function that severely restricts their daily life , or people with impaired immune function due to human immunodeficiency virus (HIV) that make daily life almost impossible. These people can receive one dose of influenza HA vaccine as part of routine vaccination. In addition, the influenza vaccine and the COVID-19 vaccine can be administered on the same day. Please consider getting vaccinated together with the COVID-19 vaccine. We would appreciate your cooperation in spreading this information to the media. 

(Reference) Summer Infectious Disease Control Measures | Ministry of Health, Labour and Welfare Phone number: 0120-995-956 Reception hours: 9:00 AM - 5:00 PM, Monday to Friday (excluding public holidays and year-end/New Year holidays) According to the infectious disease surveillance data for the 34th week of 2026 (August 17th to August 23rd), the number of reported influenza cases per sentinel site was 1.11 (number of sentinel sites: approximately 3,000 nationwide, number of reported cases: 4,094). 

Since this exceeds the threshold of 1.00 used as the benchmark for the start of an epidemic, it is believed that the influenza season has begun again this year. We have opened a consultation service for infectious diseases and vaccinations, including influenza . Please feel free to use it. *The telephone number changed on April 1, 2025 

Every flu season is different, and as we've seen many times, flu seasons can vary widely around the world, making it unknowable if this early arrival will be duplicated in North America or Europe.  

While I generally like to wait until October to get my seasonal flu shot, if this trend continues, I expect I'll be rolling up my sleeve a little earlier this year. 

UK National Risk Register 2026 - Urges Citizen Preparedness

 

#19,311

In August of 2008 we looked at the first UK National Risk Register - which ran just 52 pages - and cited pandemic flu as the #1 threat facing the nation.  It's prep advice to the public was fairly limited, essentially urging:

Creating a core stock of essential supplies. This could include bottled water, a battery powered radio, torch, tinned food and alternative heating sources.

Four years later, a slightly larger (58 page) 2012 update was released, which kept pandemic flu at the top of their threat board, but added coastal flooding, terrorist attacks, severe space weather, prolonged power or gas outages, and even volcanic threats to the list.

The last time we looked at the UK Risk Register was in August of 2023, which by that time has expanded to nearly 200 pages. That edition of the NRR detailed 89 risks, within 9 risk themes:

• Terrorism
• Cyber
• State threats
• Geographic and diplomatic
• Accidents and systems failures

• Natural and environmental hazards

• Human, animal and plant health

• Societal

• Conflict and instability

Since then the world has changed radically, with the rise of A.I. and cyber threats, increasing global tensions in Europe and the Middle East, climate change and a record setting El Nino on the horizon, aging infrastructures, and growing economic threats. 

The 2026 edition of the NRR has expanded to a daunting 223 pages - so large that it is accompanied by a 27-page `Guide to the 2026 Risk Register' - which will hopefully provide a more palatable gateway for casual reader. 

 Admittedly, the NRR isn't geared to the general public, as explained below:

This edition of the NRR is available to all but not targeted at the general public. Advice for individuals, households and communities on preparing for a wide range of risks can be found on the Prepare website.

In recent years we've seen a growing willingness of European nations to ask citizens to prepare for emergencies, including 2025's Denk Vooruit: The Netherlands National Citizen Preparedness Drive and last year's EU Commission call for all households to prepare for a wide array of disasters.  

The NRR guide goes on to say:

The risks outlined in the 2026 NRR are significant, but they are not inevitable. Resilience is a national endeavour that relies on a combination of robust government coordination and the proactive responsibility of every individual, business, and community. It is particularly important for owners and operators of CNI to ensure continued delivery of the essential services that underpin UK society and way of life.This “whole-of-society” approach is built on deep partnerships, where we recognise our vital roles in preparing for, responding to, and recovering from emergencies.

The power of collective readiness

When communities take steps to prepare, they act as a force multiplier for national resilience. By managing what they can at home and with those around them, those in a position to do so reduce the immediate demand on frontline services. This ensures that emergency responders and limited resources can be prioritised for those who may need more support or who are in the greatest need. This collective effort is vital to ensure that the national resilience system remains strong enough to protect everyone when it matters most.For further guidance, resources, and advice on bolstering personal and household readiness, visit the Prepare website.

While the full 2026 NRR provides a remarkably detailed UK-centric disaster reference guide, it isn't exactly light reading. Most will find the Guide to the NRR - which still puts a `Disease X' pandemic at the top of their threats list - far more accessible. 

Since it is impossible to summary a 223 page document here, I'll simply provide the links and recommend you download, and peruse, both. 

Documents

National Risk Register 2026

PDF, 22.6 MB, 223 pages

A Guide to the National Risk Register 2026

PDF, 4.75 MB, 27 pages

Next month is National Preparedness Month, and - as we've done every year for nearly 2 decades - AFD will focus a good deal on individual, community, and national preparedness.

Having survived more than a few hurricanes, my personal recommendations include:

• A battery operated NWS Emergency Radio to find out what was going on, and to get vital instructions from emergency officials
• A decent first-aid kit, so that you can treat injuries
• Enough non-perishable food and water on hand to feed and hydrate your family (including pets) for the duration
• A way to provide light when the grid is down.
• A way to cook safely without electricity
• A way to purify or filter water
• A way to handle basic sanitation and waste disposal.
• A way to stay cool (fans) or warm when the power is out.
• A small supply of cash to use in case credit/debit machines are not working
• An emergency plan, including meeting places, emergency out-of-state contact numbers, a disaster buddy, and in case you must evacuate, a bug-out bag
• Spare supply of essential prescription medicines that you or your family may need
• A way to entertain yourself, or your kids, during a prolonged blackout

Being prepared doesn't guarantee you and your loved ones will come through a major disaster unscathed. But it is relatively cheap insurance, and when things do go sideways, it can substantially improve your chances. 

Norwegian Veterinary Institute Reports Another HPAI H5N5 Infected Polar Bear on Svalbard Island

 

 

Credit: Multiple transatlantic incursions of HPAI 

clade 2.3.4.4b A(H5N5) virus into North America 

and spillover to mammals

#19,310

Although most of the world is primarily concerned with HPAI H5N1, in northern Europe, Iceland, and parts of Canada, a different avian flu subtype - HPAI H5N5 - has been making inroads as well. 

Additionally, here in the United States HPAI H5N5 infected and killed a resident of Washington State last November, following contact with backyard birds.

In the summer of 2022, the Norwegian Veterinary Institute reported both H5N1 and H5N5 for the first time in wild birds on Svalbard, which lies above the Arctic circle (see More HPAI (H5N5 & H5N1) Detected In Arctic (Svalbard).

Last May, in Norway Veterinary Institute Reports HPAI H5N5 In Polar Bears on Svalbard Island, we looked at a report of the recent detection of HPAI H5N5 virus in both a dead walrus and a polar bear on Svalbard Island.

Although no other animals were confirmed infected during this investigation, there were eye witness accounts of two other polar bears exhibiting potential neurological symptoms.

Five weeks ago, in Preprint: HPAI H5N5 in a Polar Bear and Atlantic Walrus, Svalbard, 2026, with Widespread Seroconversion in Polar Bears, we saw a report indicating that H5N5 exposure is far more common among polar bears on Svalbard island than previously thought.

Somewhat surprisingly, most polar bears appear to survive H5N5 infection, although severe (and likely neurotropic) illness can occur.

Yesterday the Norwegian Veterinary Institute reported on a second polar bear - recovered in June some 23 km distant from the one found in May - has tested positive for H5N5. 

(translation)
Bird flu detected in another polar bear in Svalbard
Published 25.08.2026

The Norwegian Veterinary Institute has detected avian influenza in a young polar bear found dead on the northern tip of Spitsbergen. This is the second time the virus has been detected in polar bears in Norway and Europe.

The detected highly pathogenic avian influenza (HPAI) virus is of the subtype H5N5, a type of the virus that has been previously detected in Svalbard: In wild birds for the first time in 2022 , in a walrus in 2023 , in arctic foxes in 2025 , and in a polar bear and walrus in the spring of 2026. This latest detection is the second in polar bears in Norway and Europe.

Highly pathogenic avian influenza viruses have also previously been detected in carnivorous mammals such as red foxes, otters and lynxes on mainland Norway after infection from wild birds.

Sampled in the field by the District Governor

The polar bear, a young individual, was found dead on Æøya, near Virgohamna. The animal was sampled by the Governor in June 2026, after avian influenza virus was detected in a dead polar bear and a dead walrus in Raudfjorden in May 2026. The distance between the two findings of dead animals is approximately 23 kilometers.

- After the findings on the polar bear and walrus in Raudfjorden, we also recommended sampling the polar bear that was on Æøya, says veterinarian and wildlife health specialist at the Veterinary Institute Knut Madslien.

The samples from the polar bear were then sent to the Norwegian Veterinary Institute and tested for avian influenza virus and rabies. Highly pathogenic avian influenza virus was detected in samples from both the brain and nose. Rabies virus was not detected.

Bird flu virus is circulating in the highlands

"The findings are part of a trend where highly pathogenic avian influenza virus is increasingly being detected in mammals in Europe. At the same time, the virus has spread to new areas in recent years, including the Arctic, where it may have consequences for vulnerable populations and ecosystems," explains Ragnhild Tønnessen, avian influenza coordinator at the Norwegian Veterinary Institute.

- Our researchers, in close collaboration with the Norwegian Polar Institute and other partners, have found that a large proportion of the polar bears examined in Svalbard after 2022 have been exposed to previous avian influenza infection. Although we currently have limited knowledge of the consequences this has for the polar bears, the results indicate that the virus is circulating in the population and that exposure is more widespread than detections in dead animals alone would indicate, says Tønnessen.

Increased infection pressure in mammals

Most avian influenza viruses are best adapted to be transmitted between birds. However, mammals can sometimes be infected through direct contact with sick or dead birds or other mammals infected with the virus.

The Veterinary Institute will conduct further investigations of the detected virus to characterize it more closely and clarify whether it shows signs of being specifically adapted to mammals.

Second detection in polar bears in Europe

In other predators, such as red foxes and lynxes, avian influenza can cause clinical signs of brain disease. Neurological signs such as circling gait, tilted head position, paralysis and reduced shyness towards humans are common.

Avian influenza virus in polar bears has been scientifically published twice previously: In a young male polar bear found dead in Alaska in August 2023 and in a young male polar bear found dead in Raudfjorden on Svalbard in May 2026. However, it is not known how the virus affects individual individuals or the population of polar bears.

– This finding strengthens the indications that highly pathogenic avian influenza virus can also affect polar bears, and that young individuals are particularly vulnerable. This is also consistent with findings in other carnivorous mammals, where the virus mainly affects younger individuals. However, the knowledge base is still very limited and it is important to gain more knowledge about how the virus can affect polar bears, says Madslien.

Report if you observe dead or sick animals and birds

Both highly pathogenic avian influenza and rabies are serious diseases found in Svalbard and can be transmitted to humans. Contact with sick and dead animals should therefore be avoided.

If sick or dead animals are observed on Svalbard, it is important that the findings are reported to the Governor . This is important to obtain an overview of disease incidence and mortality, although it does not always trigger sampling. If avian influenza is suspected in birds and other animals on the mainland, the Norwegian Food Safety Authority must be notified .

The Norwegian Veterinary Institute is the national reference laboratory for avian influenza and has molecular methods for the detection and characterization of avian influenza viruses.

Admittedly, HPAI H5N5 remains a minor player in the world of avian flu, but it has shown remarkable tenacity, persisting and even thriving in some high latitude regions of the Northern Hemisphere. 

A recent study (see J. Virology: Risk assessment of avian influenza A(H5N5) virus from the first human case using the ferret model) found that while the Washington State isolate replicated robustly in mammalian cells and caused severe disease, it still lacked adaptations supporting efficient airborne spread. 

Six years ago HPAI H5N8 subtype dominated the world's avian flyways, only to be abruptly supplanted by a new and improved H5N1 in 2021. 

A reminder of just how quickly the avian flu-scape can change, and why we continue to watch this subtype with interest. 

Australia H5N1 Update: CSIRO Testing 1st Land Mammal (Red Fox) For Suspected Infection

 

#19,309

Our almost daily dose of increasingly bad H5N1 news from Australia continues with an announcement today that their first suspected HPAI infection in a land mammal (a red fox recovered in Osborne) - a suburb of Adelaide - has been forwarded to their national testing lab for confirmation. 

Their progression of the virus moving from migratory birds to local birds to marine mammals and now potentially to land mammals (and likely on to poultry and/or livestock in the future) mirrors what we've seen in other regions of the world following the arrival of HPAI. 

South Australia continues to be the nation's hotspot for HPAI detections, although only a small fraction of the more than 29,000 citizen hotline reports have been investigated across the nation.  

As we saw 2 weeks ago, in Australia Changes How They Report H5N1- Australia now only counts `events' - not individual confirmed infections.  So one event could represent multiple bird/animal deaths.  

H5 bird flu testing update 26 August

Wednesday 26 August 2026 BiosecurityMedia release

There are five new suspect H5 bird flu events in South Australia since yesterday’s update.

The new suspect events include:

1. Australian raven Limestone Coast – Robe
2. Little penguin Limestone Coast – Southend
3. Greater crested tern Murray and Mallee – Coonalpyn
4. Pacific gull Kangaroo Island – Baudin Beach
5. Red fox Metropolitan – Osborne

Samples from these events have been sent to ACDP for confirmatory testing, with results expected to be known in the coming days.

This brings the current number of suspect H5 bird flu events in South Australia to 41.

The CSIRO’s Australian Centre for Disease Preparedness (ACDP) has no new confirmed H5 bird flu events in South Australia since yesterday’s update.

There are 195 confirmed H5 bird flu events in South Australia.

In line with national protocols, the South Australian Government recently changed how we report on H5 bird flu detections.

Reporting is now based on events, rather than individual animal detections, where an event may involve one or more animals. The number of positive events captures all previously reported individual confirmed detections.

An interactive map is available on the H5 bird flu website with up-to-date information on event locations: see current situation

There remains no H5 bird flu detections in poultry or other livestock. The risk to human health of H5 bird flu remains low.

Engagement with primary industries, the wildlife sector, and the broader South Australian community continues as part of the South Australian Government’s commitment to deliver the most comprehensive and effective wildlife and industry surveillance, reporting and preparedness efforts possible.

South Australians are encouraged to continue being vigilant in reporting sick and dead birds and other wildlife.

Avoid touching sick or dead birds and other wildlife. Record what you see. Report it to the Emergency Animal Disease Hotline on 1800 675 888.

For the latest updates, information and advice about H5 bird flu in South Australia, including how to register for upcoming community forums, including tomorrow night (27 August) at Port MacDonnell, visit birdflu.sa.gov.au.

Yesterday South Australia also announced the approval of bird flu vaccinations for a limited number of endangered native birds residing at Cleland Wildlife Park has been approved. 

Bird flu vaccination program approved for Cleland Wildlife Park

Native birds at Cleland Wildlife Park − including critically endangered species such as orange-bellied parrots and regent honeyeaters – have been approved for vaccination as part of the South Australian Government’s response to H5 bird flu.

The vaccination program has also been approved for a range of other native bird species at Cleland Wildlife Park, including:

• Magpie geese
• Australian pelicans
• Regent parrots
• Red-tailed black cockatoos

Developed by the South Australian Government, the vaccination program at Cleland will initially see up to 100 native birds vaccinated across over 30 different species.

The program has received the relevant approvals in line with the national framework that supports targeted vaccination of priority native bird species that are captive or managed.

A range of factors are considered when identifying priority species for vaccination, including the conservation status and value of the species, the likelihood of catching bird flu, and whether vaccination can be delivered safely and effectively, according to
regulatory requirements.

There remains no H5 bird flu detections in poultry or other livestock. The risk to human health of H5 bird flu remains low.

South Australians are encouraged to continue being vigilant in reporting sick and dead birds and other wildlife. Avoid touching sick or dead birds and other wildlife.

Record what you see. Report it to the Emergency Animal Disease Hotline on 1800 675 888.

For the latest updates, information and advice about H5 bird flu in South Australia visit birdflu.sa.gov.au.

For now, H5N1 has not been detected in Australian poultry or livestock, but that could be short-lived. Four weeks ago we looked at a preprint by Raina MacIntyre et al. (HPAI H5N1 risk in Australia: a model for the prediction of poultry outbreaks) which included a map showing (then) current HPAI H5 detections overlaying poultry production zones.

As we've discussed often, even countries with long experience dealing with HPAI (see Front. Vet. Sci: Biosecurity deficiencies in HPAI-affected poultry farms in Korea, 2020/2021–2024/2025 seasons) have found it difficult to keep avian flu out of the henhouse.

And while things remain relatively quiet in the Northern Hemisphere, fall is just around the corner, and the expectation is avian flu will return once more with a vengeance. 

Stay tuned. 

Transb. & Emerg. Dis.: Genomic and Clinicopathological Characterization of a Reassortant HPAI H5N1 (Clade 2.3.4.4b) in an Endangered Cinereous Vulture (Aegypius monachus) in South Korea, 2026

 
Transboundary and Emerging Diseases, Volume: 2026, Issue: 1,
First published: 18 August 2026, DOI: (10.1155/tbed/2623621)

#19,308

Yesterday, in Conservation Bio: Emerging threat of avian influenza to the world's vultures, we looked - in broad terms - at the current and potential future impact of HPAI H5N1 on raptors and other scavenger birds. 

Today we've a study - published last week in Transboundary and Emerging Diseases - which looks at one specific investigation into an H5N1-infected endangered Cinereous Vulture recovered in South Korea earlier this year.

While hardly a new finding (see Cell: The Neuropathogenesis of HPAI H5Nx Viruses in Mammalian Species Including Humans), once again we see strong evidence of neurological involvement in this recovered vulture; in clinical presentation, histopathological findings, and in high titers of the virus found in brain tissue. 

This is a topic we've looked at often, most recently last month in Viruses: First Ecuadorian Pediatric Case of Multisystem and Neurological Involvement Associated with Influenza A—H5N1 Virus—Case Report, and before that, in last May's  QJM: Avian Influenza in Humans: Virology, Transmission, and Clinical Priorities.

This study also found that the HPAI H5N1 virus recovered from the vulture was a reassortant (see graphic at top of blog). Its HA, NA, and M gene segments closely resembled a G10-like East Asian H5N1 virus which circulated circa 2022–2023, while its internal genes appear derived from multiple regional and flyway HPAI and LPAI viruses.  

While much of this study is fairly technical, and will be primarily of interest to researchers, it is an excellent reminder of just how much hidden diversity there is in HPAI H5Nx in the wild, and that their evolution never stops.

I've only posted some excerpts. Those wishing a deeper dive will want to follow the link to read it in its entirety. 

Genomic and Clinicopathological Characterization of a Reassortant HPAI H5N1 (Clade 2.3.4.4b) in an Endangered Cinereous Vulture (Aegypius monachus) in South Korea, 2026

Chang-Gi Jeong, Seongwon Hwang, Taeyeong Jung, Su-Beom Chae, Tae-Nam Kim, Nchimunya Siamulonga, Serin Sim, Geonwoo Baek … See all authors
First published: 18 August 2026 https://doi.org/10.1155/tbed/2623621Digital Object Identifier (DOI)

Academic Editor: Fabian Lean

 Abstract

Clade 2.3.4.4b highly pathogenic avian influenza viruses (HPAIVs) continue to circulate widely in East Asia and undergo frequent reassortment in wild birds. Raptors are regarded as spillover hosts that may be exposed through predation or scavenging, yet integrated clinicopathologic and genomic investigations in cinereous vultures remain limited. 

Here, we describe a fatal H5N1 HPAIV infection in a cinereous vulture (Aegypius monachus) found in South Korea on January 17, 2026. On presentation, the cinereous vulture showed severe neurologic dysfunction, including inability to stand, right-sided head tilt with pathologic nystagmus, reduced oculocephalic and palpebral reflexes, and intermittent bilateral leg tremors. The cinereous vulture died within 2 days after rescue, and a complete necropsy was performed. 

Hematologic and biochemical testing revealed marked heterophil predominance, severe lymphopenia, mild monocytosis, and globulin values near the upper end of the reference interval. An oropharyngeal swab tested positive for influenza A virus, and a virus isolate, designated A/Cinereous_Vulture/Korea/26-JBN47/2026(H5N1), was recovered in embryonated chicken eggs. Histopathology showed nonsuppurative encephalitis and necrotizing myocarditis, and influenza A nucleoprotein was detected immunohistochemically in neurons and cardiomyocytes.

Tissue real-time RT-PCR showed the lowest cycle threshold value in the brain. Whole-genome sequencing demonstrated that 26-JBN47 belonged to clade 2.3.4.4b and contained a polybasic HA cleavage site (PLREKRRKR/GLF). Segment-level phylogenetic analysis revealed a reassortant genome constellation comprising a maintained H5N1 backbone in HA, NA, and M; low PAIV (LPAIV)-associated but H5N1-incorporated PA and NP segments; flyway-associated PB2 and NS segments; and a PB1 segment phylogenetically linked to regional LPAIV lineages. 

Molecular marker analysis identified multiple substitutions previously reported to be associated with receptor-binding properties, polymerase-related fitness, virulence, and host-response modulation, whereas canonical PB2 mammalian-adaptive markers were absent. These findings show that 26-JBN47 was a reassortant clade 2.3.4.4b H5N1 HPAIV associated with systemic disease and clinicopathological findings consistent with neurotropic and cardiotropic infection in a cinereous vulture. They also support the potential value of scavenging raptors as sentinels of local or regional HPAIV circulation involving reassortant viruses in East Asia.

        (SNIP)

5. Conclusion

This study documents a fatal clade 2.3.4.4b H5N1 HPAIV infection in a cinereous vulture in South Korea and links severe clinicopathologic disease with a reassortant viral genome. The affected cinereous vulture developed marked neurologic dysfunction and showed nonsuppurative encephalitis, necrotizing myocarditis, and viral antigen distribution in the brain and heart, with the highest viral RNA burden detected in the brain.

Together, these findings are consistent with neurotropic and cardiotropic infections in this case. Genomic analyses showed that 26-JBN47 retained an East Asian H5N1 backbone in the HA, NA, and M segments, which clustered with G10-like viruses, whereas the internal genes reflected multiple reassortment histories involving regional AIV gene pools. The molecular marker profile was broadly consistent with contemporary avian-origin clade 2.3.4.4b H5N1 viruses and did not indicate advanced mammalian adaptation.

These findings show that cinereous vultures can develop severe fatal diseases after HPAIV infection and support their potential utility as sentinels of local or regional HPAIV circulation involving reassortant viruses near wildlife interfaces in East Asia.

       (Continue . . . )