HK CHP Reports 3 H9N2 Cases On Mainland

 

#19,266

Although it received brief mention (see below) in the July 17th WPRO avian flu update, Hong Kong's CHP acknowledged 3 recent H9N2 cases in their weekly avian flu report today.  

As usual, details are scant, but we get a little more from the following WHO WPRO report:

Human infection with avian influenza A(H9N2) virus

From 10 to 16 July 2026, three new cases of human infection with avian influenza A(H9N2) virus were reported to WHO in the Western Pacific Region. All three cases were from China. 

The first case is a 4-year-old male from Guangxi Province, with symptom onset on 26 June 2026. The second case is a 4-year-old male from Jiangsu Province, with symptom onset on 22 June 2026. The third case is a 44-year-old male from Guangdong Province, with symptom onset on 26 June 2026. 

All three cases had exposure to live poultry. The first and second cases had mild symptoms and now recovered; the third case had underlying comorbidities and is curently receiving treatment in the intensive care unit.

Since 2015, a total of 173 cases of human infection with avian influenza A(H9N2), including two deaths(both with underlying conditions), have been reported to WHO in the Western Pacific Region. Of these,170 were reported from China, two were from Cambodia, and one was from Viet Nam.

While most human H9N2 cases have been reported out of China (see below), this year Europe saw its first (imported) human infection with H9N2 in Italy (see WHO DON: Avian Influenza A(H9N2) - Italy (Ex Senegal)).

It is assumed that most cases go unreported, since human infections tend to be mild or moderate (but occasionally severe), and very rarely are non-hospitalized patients tested for novel flu. 

Although there is currently no evidence of sustained or efficient human-to-human transmission of H9N2, the virus remains poorly controlled in poultry, and appears on a path towards greater mammalian adaptation.

While trying to predict the source of the next influenza pandemic is a mug's game, H9N2 shows up twice the top 10 zoonotic influenza A viruses the CDC has pegged as having at least some pandemic potential, with the Y280 lineage having a higher emergence score than H5N1.

Given that we've already seen 2 modern influenza pandemics (1957 & 1968) caused by avian viruses spilling over from birds to humans in China, H9N2's continued evolution and spread is very much worthy of our attention. 

New Zealand to Require Biosecurity Plans From Poultry Sector as Australia's H5N1 Count Rises to 27

#19,265

No unexpectedly, the results overnight from Australia's National Lab CSIRO have confirmed the 7 suspected bird flu detections reported yesterday in Southern Australia, doubling their total to 14. 

H5 bird flu updates
 
28 July 2026

Attributable to Australian Chief Veterinary Officer, Dr Beth Cookson:

Testing at CSIRO’s Australian Centre for Disease Preparedness (ACDP) has confirmed H5 bird flu in 7 greater crested terns found in South Australia.

Of these, 1 was found at Cape Jaffa, 5 at Southend and 1 at Port MacDonnell.

There have now been 27 confirmed or presumed positive detections of H5 bird flu in Australia.

All of these have been wild seabirds found in coastal locations. Further laboratory analysis will be undertaken to help determine if there is evidence of local transmission.

There remains no evidence of any mass mortality events and there are no detections in poultry or in our agricultural production system.

Notably, these are native seabirds (greater crested terns), which raises concerns over the local transmission of the virus. Additional genetic testing is underway to try to determine transmission dynamics. 

Meanwhile, the tally in New Zealand remains at 2, but officials fully expect that number to increase.  Two weeks ago, New Zealand's Associate Biosecurity Minister Andrew Hoggard made it clear that - unlike a lot of other countries - the government would not be compensating poultry farmers for losses. 

Farmers told: If bird flu infects your chickens, they will die, and don’t expect compensation

Overnight New Zealand announced plans to require poultry farmers (flocks > 100) to create and submit biosecurity plans - including the management of any outbreaks - to the government by the end of the year.

28 July 2026
Poultry sector gets stronger biosecurity backing to fight bird flu
Hon Andrew Hoggard
Biosecurity

The Government is introducing new biosecurity regulations to help poultry farmers manage H5 bird flu, protect livelihoods, and secure domestic food supply, Biosecurity Minister Andrew Hoggard says.

“Now that H5 bird flu is here, it will almost certainly establish in wild birds.

“Cabinet has approved regulations to ensure the sector has the practices, infrastructure, reporting, and compliance tools needed to manage that risk.”

Poultry operators with more than 100 birds will be required to develop, register, and implement a farm biosecurity plan for avian disease, setting out how they will prevent and manage H5 bird flu.

“Biosecurity measures are currently voluntary in the poultry sector. While there is strong industry co-operation, farmers doing the right thing can still be put at risk by those who are not.”

“Biosecurity New Zealand and industry have been working together on a long-term approach to managing H5 bird flu. There is a good understanding of what good on-farm biosecurity looks like and plenty of information available to poultry farmers through the industry’s bird flu website”

“MPI is available, especially for smaller operators, through it’s On Farm Support team to help with the development of biosecurity plans and enhanced preparedness, including response plans.”

The regulations will focus on outcomes and the risks operators must manage, while giving them flexibility in how they do it.

Operators will need to keep records, undergo audits, and show clear plans for humane culling, disposal, cleaning, and disinfection if their operation is affected.

“When H5 bird flu becomes widespread in wild birds, poultry operators will face a constant infection risk. These regulations will lift on-farm readiness and give farmers the best possible chance to protect their businesses.”

Mr Hoggard says regulating the sector under the Biosecurity Act 1993 will also help protect food supply, trade, wild and captive birds, other animals, and people.

MPI consulted on the proposed regulations late last year and received 36 submissions, with feedback broadly supportive.

The regulations will now be drafted and shared with the industry bodies before coming into force by the end of 2026.

 
While full details haven't been fleshed out, last August the MPI and the poultry industry signed an agreement on biosecurity, whereby the costs would be shared by both parties. 

“This agreement formally recognises industry bodies as decision-makers, alongside the Government, guaranteeing PIANZ and EPF a seat at the table if any of these diseases are detected in New Zealand.”

The agreement covers Newcastle disease, infectious bursal disease virus and all strains of high pathogenicity avian influenza (HPAI), including the HPAI strain H5N1 clade 2.3.4.4b.

“Importantly, the agreement also sets out cost-sharing arrangements between taxpayers and the industry. This recognises the benefits to both parties of being well prepared, reporting early, and responding rapidly,” says Mr Hoggard.

“By sharing the costs of preparation and response, we ensure there are strong incentives on farmers to take preventative measures while also encouraging them to report suspected disease as soon as possible.”

Under the agreement, industry will contribute 45 per cent of readiness costs for all poultry diseases and 45 per cent of response costs, with the exception of HPAI – for which industry will meet 40 per cent of the response costs.

Readiness costs can include the cost of developing plans for response operational activities, running exercises for testing plans, and applied research to improve response operations. Response costs can include diagnostics, communications and activities to control a disease.

For backyard flock owners (with < 100 birds), the MPI offers the the following advice:

Bird flu and protecting your birds and other pets

While New Zealand has been planning for this grim eventuality for years, even countries with decades of experience dealing with H5N1 continue to find biosecurity a challenge.

For more, you may wish to revisit:

Front. Vet. Sci: Biosecurity deficiencies in HPAI-affected poultry farms in Korea, 2020/2021–2024/2025 seasons

South Australia Reports 7 More `Suspect' H5N1 Detections In Native Shore Birds

 

Video Link 

#19,264

Once again Southern Australia is reporting a number (n=7) of `presumed positive' H5N1 tests in local seabirds, all found in greater crested terns recovered on the state's southeast Limestone Coast (5 at Southend Jetty near Beachport, plus 1 at Cape Jaffa and 1 at Port MacDonnell).

Some of the birds were sick, while others were dead. This comes on the heels of yesterday's announcement of  South Australia Confirms 6th & 7th Seabird Infection - National Ttl = 20,

Samples from all 7 birds have been sent to the National laboratory CSIRO for confirmation and WGS (Whole Gene Sequencing). If confirmed, this would bring the nation's total to 27. 

Authorities continue to stress that, so far, there have been no detections in poultry, or indications of any large-scale deaths in wildlife.  This recent change, however - from detections in migratory seabirds to local species - raises new concerns over how the virus may be spreading. 

Add in the close proximity of these recent reports to denser poultry production regions, and spillovers into the agricultural section become a genuine concern. 

A few hours ago Professor Raina MacIntyre posted the following on X, showing the recent H5N1 detections overlaid on a map of poultry production regions.

You can visit the interactive map at EPIWATCH. 

While past performance isn't always a guarantee of future results, the unfortunate history with HPAI H5N1 - particularly over the past 5 years - has been once it reaches new territories, it tends to establish itself fairly quickly in local wildlife. 

We should expect an update from CSIRO in the next couple of days. 

Stay tuned. 

South Australia Confirms 6th & 7th Seabird Infection - National Ttl = 20

 

#19,263

As mentioned yesterday, Australia's National Lab CSIRO was testing samples from 2 suspected H5N1 infected seabirds from South Australia. Not unexpectedly, both have now been confirmed, bringing the nation's total to 20 detections. 

While most of these H5N1 infections have been found in migratory seabirds, 3 of the 7 from South Australia have been in local seabirds (greater crested terns).

Two brief updates.  First from https://www.birdflu.sa.gov.au/ 

Current situation

South Australia’s first confirmed detection of H5 bird flu was in a wild migratory bird (southern giant petrel) on Wednesday, 24 June at Knights Beach at Port Elliot on the Fleurieu Peninsula.

Further confirmed detections include a giant petrel (8 July at Hardwicke Bay, Yorke Peninsula); a southern giant petrel (10 July at Emu Bay, Kangaroo Island); a northern giant petrel (10 July at Port Vincent, Yorke Peninsula); and three greater crested terns (10 July at Robe, Limestone Coast; 26 July at Semaphore, metro Adelaide; and 26 July at Robe, Limestone Coast).

The strain of virus is consistent with the strain detected in the Southern Indian Ocean Sub-Antarctic Territories, including Heard Island.

This strain has not been detected in poultry and has not become established in any part of Australia.

Up-to-date national information is available at birdflu.gov.au.

 

Second, from national birdflu.gov.au website.

Detection of H5 bird flu

As of 1.00 pm AEST, 26 July 2026, Australia has 20 confirmed detections of H5 bird flu in wild seabirds.

• 10 in Western Australia (WA)
• 7 in South Australia (SA)
• 2 in New South Wales (NSW)
• 1 in Queensland (QLD).

This is the serious H5 bird flu strain that has been circulating globally.

There have been no detections in poultry or the wider agriculture industry. There is no evidence of any large scale deaths.

The Consultative Committee for Emergency Animal Disease (CCEAD) has reviewed its previous advice and continues to support heightened biosecurity measures in poultry for up to a further two weeks while risk-based guidance is finalised. This includes options for states and territories to utilise non-mandatory measures, including voluntary housing of free-range poultry where practical and consistent with animal welfare requirements.

State and territory governments are responsible for surveillance and response activities on the ground. They are actively working with industry to provide guidance on implementation of enhanced biosecurity measures, as appropriate. Find out more about bird flu in your state or territory.

National coordination is being led by the Department of Agriculture, Fisheries and Forestry (DAFF).

The risk to human health remains low.

Australia is well prepared to respond quickly.

Preprint: A lethal human H5N5 influenza virus isolate exhibits low pandemic risk traits

 

Credit: Multiple transatlantic incursions of HPAI

clade 2.3.4.4b A(H5N5) virus into North America

and spillover to mammals 

#19,262

We've been following HPAI H5N5's spread in birds and small mammals - first in Europe, then in Canada and the United States - for several years, but last November we saw the first (and fatal) documented infection of a human with HPAI H5N5 in a elderly backyard keeper of poultry in Washington State. 

Like H5N1, H5N5 isn't a single virus, but rather represents a growing array of genetically distinct genotypes which share related H5 and N5 surface proteins

The virus detected in the Washington State patient is similar to - but not an exact match - to the H5N5 viruses that have infected cats in Iceland, raccoons in Canada,  and Polar Bears on Svalbard Island. 

Last March, Viral Creep: H5N5 Update, we looked at its evolution as it has spread across the United States;  shifting from almost exclusively EA H5N5 prior to last fall, to largely EA/AM H5N5 since November. 

Based on USDA Data - Graph created with Gemini

The USDA defines these two strains as:

EA = Eurasian; AM = North American; the EA H5 (2.3.4.4) viruses are highly pathogenic to poultry.

EA/AM: reassortant of H5 goose/Guangdong and North American wild bird lineage

I mention this distinction because today's preprint focuses exclusively on the Washington State case's isolate, which they describe as having  `. . . a clade 2.3.4.4b hemagglutinin and internal gene segments cluster with currently circulating Eurasian lineage clade 6 (EA6) strains'.

Since late 2025 most U.S. H5N5 isolates have been classified as EA/AM, indicating reassortment with local (North American) LPAI viruses.

Whether this makes any practical difference in their pandemic risk is unknown, but the findings of this - or any other study - may not hold true across the full, and continually expanding range of H5N5 viruses.  

Indeed, the authors cite another study from 2024 (the above mentioned Cell Reports by Erdelyan et al.) which reported A(H5N5) viruses demonstrated rapid 100% mortality and some transmission in ferrets.

But more reassuringly - at least in the case of the isolate retrieved from the Washington State patient - that virus displayed relatively low pandemic risk traits:

• It replicated relatively poorly (compared to seasonal H1N1) in upper respiratory cell cultures, 
• It has a more avian-like pH inactivation point (about 5.5)  compared to human-adapted flu strains
• And - unlike in the Erdelyan et al. study- infected ferrets did not infect healthy co-housed ferrets.

While reassuring, the old adage applies.  When you've seen one novel flu virus, you've only seen one novel flu virus. 

Due to its length, I've only posted the abstract and some excerpts. Follow the link to read it in its entirety. 

A lethal human H5N5 influenza virus isolate exhibits low pandemic risk traits
Michelle N. Vu, Grace E. Quirk, Alexis E. Smathers, Kaitlyn Busfield-Thomason, Alaina L. Dorazio, Katelyn R. Domke, G. M. Humber, John Sembrat, Anita K. McElroy, Valerie Le Sage,  Seema S. Lakdawala
doi: https://doi.org/10.64898/2026.07.20.739507
This article is a preprint and has not been certified by peer review  
 
Preview PDF

Abstract

In fall of 2025, a fatal infection of highly pathogenic avian influenza (HPAI) virus H5N5 occurred. To define the risk of this emerging virus to humans, we performed a comprehensive analysis based on our established triage. Serological analysis revealed that humans across all birth years had no detectable neutralizing antibodies to this H5N5 isolate.

Further characterization revealed a lack of phenotypic signatures associated with epidemiologically successful influenza viruses in humans, including reduced replication in human airway cells and an avian-like pH of inactivation.

Additionally, assessment of H5N5 in ferrets revealed a lack of direct contact transmission and moderate disease severity. H5N5 infection in ferrets with prior immunity against the 2009 H1N1 pandemic strain resulted in fewer clinical signs and reduced viral shedding. Together our data suggest that the current H5N5 HPAI lineage poses a low pandemic risk.

Importance 

HPAI H5N5 viruses have caused widespread infection and death in avian species, and characterizing their pandemic risk traits is critical to understanding the threat posed to humans. In this work we analyzed an isolate that resulted in a human fatality in 2025.

We found that this strain lacks many key features of influenza viruses with epidemiological success in humans including reduced growth in human lung cultures, a pH of inactivation less than 5.0, and lack of transmission to cohoused recipient ferrets. Prior immunity with seasonal H1N1 strain also reduced the viral load and disease burden of the virus.

Taken together, these data suggest that currently circulating H5N5 poses a low risk to humans but highlights the importance of phenotypic characterizations for future risk assessments as the virus evolves in wild birds.

(SNIP)

Discussion

The H5N5 (A/Washington/2148/2025) virus that caused a lethal human infection in 2025 was characterized for its pandemic potential with in vitro characterization of H5N5 revealing no neutralizing antibodies across a panel of human sera, indicating widespread susceptibility in the population.

However, in vivo assessment indicated that prior H1N1pdm09 immunity reduced viral burden and disease signs during H5N5 infection, suggesting that there is some protection in the human population from prior IAV infection. This observation is of particular interest given evidence that cross-reactive NA immunity to N1 from human seasonal H1N1 strains was protective against H5N1 infections (19–21), suggesting that there is likely another mechanism of action since the NA proteins are distinct subtypes.

In contrast to our data, characterization of two closely related (>99% nucleotide identity) H5N5 strains by Erdelyan et al. demonstrated high mortality in ferrets after infection (6). These two representative strains were isolated from a bird (crow) and a mammal (raccoon) and displayed a preference for binding avian influenza virus receptor, 3’SLN-linked sialic acid (6). Sequence comparison of the crow and racoon strains as well as the lethal human H5N5 isolate characterized herein indicates that there are no differences at canonical mammalian adaptive sites (Supplemental Table 1). The raccoon strain had modest transmission to two of three cohoused recipient ferrets, with one displaying clinical disease and another one only seroconverting, whereas we did not observe transmission to our cohoused recipients (Figure 2B).

Differences between the study outcomes could be due to the dose of the crow and racoon inoculums, which was 10x higher, differences in virus strains, and the duration of the cohoused exposure. A limitation of our study includes the assessment of only one H5N5 isolate, but there are currently no other human H5N5 isolate to compare to. Further characterization of circulating H5N5 strains is warranted to identify potential strains of higher pandemic potential.

H5N5 continues to circulate in wild bird populations in the US and Europe (22, 23) and thus will continue to evolve and adapt to new hosts. Ongoing surveillance and characterization studies are therefore warranted given its prevalence. Our in vitro studies provide guidance for targeted risk assessment studies in the future. We observed that H5N5 was stable in the environment at mid-range humidity levels and had NA activity similar to the H1N1pdm09 strain. However, H5N5 pH of inactivation was higher than 5.0, and this virus had poor replication capacity in HBE cultures.

Rather than full characterizations of evolving H5N5 strains, future studies could focus on pH of inactivation and HBE growth. Emerging isolates with higher replication fitness in HBE cultures and pH of inactivation ≤5.0 will be of higher risk and could then be tested for ferret transmission.

Australia: CSIRO Confirms Qld's H5N1 - SA Reports 2 `Suspected' Local Birds

 
Confirmed Positive H5N1 in Birds (n=18)

#19,261

While there was never much doubt, we now have confirmation from Australia's National Lab CSIRO that the seabird recovered from Moreton Island  (25 miles N.E. of Brisbane) has tested positive for H5N1.

H5 bird flu confirmed in a wild seabird found at Moreton Island

A dead petrel found by Queensland Parks and Wildlife Service (QPWS) rangers at Moreton Island (Mulgulpin) has been confirmed positive for H5 high pathogenicity avian influenza (H5 bird flu) in laboratory tests by the CSIRO Australian Centre for Disease Preparedness.

The positive test is the first confirmed detection of H5 bird flu in Queensland.

There remain no detections in poultry, nor evidence of large-scale deaths in any animals in Queensland.

The risk to human health remains low.

The community is being urged to continue to report sick or dead wild birds.

Queensland has been preparing for H5 bird flu and has strong response arrangements in place. Australia also has national arrangements to respond to emergency animal disease incidents.

Australia’s first case of H5 bird flu was reported on 20 June 2026 in Western Australia, with further detections in wild seabirds in WA, SA and NSW.

Department of Primary Industries Chief Veterinary Officer Dr Allison Crook said the confirmed positive detection was expected, and the Queensland Government was well prepared to respond.

“We have known that a H5 bird flu detection in Queensland was a matter of when, not if,” Dr Crook said.

“This confirmed positive result has not impacted our poultry sector or native wildlife.

“We have further escalated our surveillance program throughout the state, and are delivering heightened H5 bird flu awareness and engagement activities to ensure industries and communities know what to do.

“There have been more than 1,000 reports from Queensland to the hotline since the first reported case on 20 June 2026, and I thank the public for their support.

“I encourage the community and industry to continue to be vigilant,” Dr Crook said.

“If you find sick or dead wild birds or wildlife, avoid contact, keep children and pets away, record what you see, and report immediately to the Emergency Animal Disease Hotline on 1800 675 888.”

Meanwhile Australia's ABC News is reporting that South Australia has recovered 2 deceased local birds (greater crested terns), and has sent samples to CSIRO for confirmation.  While not explicitly stated in the article, this generally indicates a local test has returned a positive result.

Two additional H5 bird flu cases suspected in SA, including first on a metro beach

While I haven't found any official press releases, ABC News quotes SA Environment Minister Emily Bourke as saying one of these birds was recovered just 4 km from where Australia's first local infected seabird was detected earlier this month.

They quote the SA Environmental Minister as saying:

 "Unfortunately, we are finding that these two cases are in our local [bird] species, so we need to send these tests off now to Geelong for them to have confirmation at that centralised location that they are, or are not, the H5 high strand of this disease." 

Until now, all but one detection of H5N1 in Australian seabirds have been in migratory species.  Additional spread in local birds, while not unexpected, increases the chances of H5 establishing a permanent beachhead.

Results from CSIRO are expected early next week.