Australia: H5 Bird Flu Reported on Macquarie Island

 
Macquarie Island - Credit Wikipedia

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Six weeks ago Australia announced they would soon be withdrawing their research team from remote Macquarie Island - located about halfway between Australia and Antarctica - over concerns that bird flu would arrive and decimate that island's wildlife much as it did on Heard Island last year. 

Citing `psychosocial risks' to personnel who were stationed there, DCCEEW decided to temporarily extract all personnel from the research station.

Today, Guy Barnett, Tasmanian Minister for Environment and Climate Change, announced that the evacuated research team brought back with them samples from the island which have tested positive for H5 bird flu.

15 October 2026

Guy Barnett, Minister for Environment and Climate Change

H5 bird flu has been detected in a Southern elephant seal and a kelp gull on Macquarie Island.

Samples collected from a Southern elephant seal and a kelp gull on Macquarie Island were returned with island personnel and subsequently tested returning a positive result for H5 bird flu.

This is the first recorded detection in a marine mammal in Tasmania.

As bird flu continues to be detected in Tasmania, members of the public are encouraged to continue reporting sick or dead birds. Reports play an important role in helping authorities detect and respond to potential cases.

Avoid contact with sick or dead birds and report sightings through https://nre.tas.gov.au/reportbirdflu or by calling the Emergency Animal Disease Hotline on 1800 675 888.

The Department of Natural Resources and Environment Tasmania provides regular public updates through media releases. The latest testing and surveillance figures are updated on the department's website.

More information is available at www.nre.tas.gov.au/BirdFlu.

While there are no reports of mass casualties on Macquarie Island, four months ago, in Preprint: Mass mortality of southern elephant seals during multi-species outbreak of HPAI H5N1 on sub-Antarctic Heard Island, we saw that the carnage from the Heard Island outbreak was worse than originally feared, with 76% mortality among Elephant Seal pups.

Meanwhile, Australia's bird flu count continues to rise, with the latest figure showing more than 700 confirmed events, and in excess of 63,000 hotline reports by the public. 

 

Nevada Dept of Wildlife Warns on HPAI in Multiple Flocks of Wild Geese

 
Credit Wikipedia

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We've a press release from Nevada's Department of Wildlife (NDOW) - posted late yesterday - warning the public that `multiple flocks' of wild geese in the Reno/Sparks region have tested positive for HPAI.

While there aren't a lot of specifics offered in this statement (precisely where, how many flocks, which subtype and/or genotype, etc.), they are urging the public to be careful around sick or dead birds, and how to report any findings. 

Local media, for now, are repeating the NDOW announcement, and adding little additional detail. First, the Nevada announcement, after which I'll have a bit more.

Nevada State Agencies Respond To Bird Flu Outbreak In Geese

The Nevada Department of Wildlife (NDOW) in coordination with the Nevada Department of Agriculture, and Nevada Division of Public and Behavioral Health have confirmed an outbreak of Highly Pathogenic Avian Influenza (HPAI) in multiple flocks of geese in the Reno/Sparks region. The public can help by identifying infected geese, notifying the proper officials and disposing geese safely to reduce transmission to other birds and species. HPAI is a highly contagious virus that can infect poultry, wild waterfowl, and in rare cases can infect livestock and humans.

HPAI symptoms in birds include:

• Sneezing, coughing, eye & nasal discharge, swelling or fluid accumulating around one or both eyes.
• Abnormal position of head or neck, poor balance and coordination, and/or circling.
• A buildup of fluid in the bird’s legs and patchy redness of the skin.
• Diarrhea and green discoloration of the feces.
• Weakness, lethargy, depression.
• Sudden death.

If the public encounters a dead goose, they are encouraged to:

• Notify the landowner responsible. For geese found on City or County Parks, please contact them for removal. City of Reno Parks can be reached at (775) 334-2270; Washoe County Parks phone is (775) 828-6612.
• Dispose waterfowl on your own property by double bagging it and placing it in municipal waste. Be sure to wear gloves, an N95 mask, and eye protection.
• If you encounter a dead goose and have poultry, change your clothes and shoes afterwards.

If the public encounters a sick goose, they are encouraged to:

• Leave the goose alone and contact NDOW at (775) 688-1500 to report the location of the goose. If this is on your property, someone will contact you as soon as possible.
• Keep pets and children away.
• If the public encounters a sick goose, they are encouraged to:
• Leave the goose alone and contact NDOW at (775) 688-1500 to report the location of the goose. If this is on your property, someone will contact you as soon as possible.
• Keep pets and children away.

If you have domestic birds, especially backyard poultry:

• Keep poultry in secure enclosures away from wild birds and waterfowl.
• Wear dedicated clothing and footwear when caring for poultry.
• Clean and disinfect tools and equipment after use.
• Store poultry feed securely and avoid placing wild bird feeders near poultry areas.
• Watch for unusual behavior, signs of illness or unexpected deaths in your flock.
• Avoid touching or handling sick or dead wild birds. Use gloves and protective gear when necessary.
• Contact a veterinarian if birds appear sick and report high mortality rates among domestic poultry to the NDA at diseasereporting@agri.nv.gov.

HPAI rarely spreads to livestock and humans. In wild waterfowl populations, it usually displays without any signs of illness and low mortality rates. It can cause mortality in some species of geese, raptors, and game birds. Poultry are highly susceptible to HPAI and mortality rates may exceed 90%. When HPAI does spread to humans, symptoms may include fever, cough, sore throat, difficulty breathing, eye tearing/irritation/redness, headaches, runny/stuffy nose, body aches, and/or diarrhea/vomiting. Transmission to humans may occur from contact with infected or potentially infected animals, animal carcasses, or surfaces contaminated with animal excretions without using proper protective clothing/equipment. If you or your family have been exposed to a sick/dead bird and develop any of these symptoms, contact your healthcare provider and let them know about your animal exposure.

Since H5Nx established itself in North America in 2021-2022, each fall we've seen an increase in HPAI as southbound migratory birds leave their high latitude roosting areas for warmer climes.

The $64 question (see 2025's H5Nx: Reassort & Repeat) is whether this year's bird flu will be a repeat of last year's strain (predominantly D1.1), or whether new genotypes have emerged. It can sometimes takes months before that question can be answered. 

Although this advisory is specifically for the Reno/Sparks area, HPAI can turn up just about anywhere in North America this time of year.  

Which means, if you raise backyard birds, frequent live markets, or have outdoor pets, now is a good time to familiarize yourselves with the risks of avian flu, and the things you can do to reduce those risks.

UF/IFAS Extension: What Backyard Flock Owners Need to Know about Bird Flu (Influenza H5N1)

 

CDC Guidance on Bird Flu in Pets and Other Animals

Saying Goodbye to An Infectious Disease Reporting Legend

 

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I've lost count how many times I've featured a Helen Branswell story in this blog, but it must run into the hundreds. She was, quite simply, one of the most prolific and capable infectious disease reporters in the world. 

Her loss, and legacy, are detailed in the STAT obituary, published yesterday. 

While I never got to meet Helen, we corresponded a number of times. Sometimes to share information, other times less formally.  She was exceptionally kind to this humble blogger, and I am saddened  - and Flublogia is diminished - by her passing.

BMC Public Health: 2018–2025 Serological study on avian influenza among occupationally exposed populations in the Poyang Lake area

 

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In 2025 a Chinese research study reported on testing environmental samples collected from southern and northern Chinese live poultry markets during 2019–2023 for evidence of avian influenza viruses. 

They examined > 64,000 samples, and found the incidence of H5, H7, and H9 influenza A detections substantially higher in southern provinces. Jiangxi, Yunnan, and Guangxi showed the highest level of environmental contamination, with positive rates of  82.3%, 49.41%, and 45.47%. 

Today we have a research study into the seroprevalence of  influenza A viruses among occupationally exposed individuals in the Poyang Lake area - located in Jiangxi province - which reported the highest environmental readings in the above report. 

Poyang Lake is the largest freshwater lake in China, and lies beneath the East Asian-Australasian Flyway. Poyang Lake also provides a habitat for more than a million migratory birds, including endangered Siberian cranes. 

Researchers tested blood from 2,437 poultry-exposed people around Poyang Lake, China, from 2018 to 2025 using hemagglutination inhibition assays. Predefined HI positivity thresholds were ≥ 1:20 for H3N8, H5N8, H5N1, H7N9, and H10N3 and ≥ 1:40 for H5N6 and H9N2.

Participants were mostly backyard poultry keepers and their households (90.3%) and live-market workers (9.7%). The median age was 62.  

While HI reactivity can't conclusively prove that an individual was previously infected by a specific virus (there's always a possibility of cross-reactivity with other viruses), it does suggest that a subject might have had a mild, or subclinical, infection with that virus sometime in the past. 

Admittedly, it would have been nice to see confirmatory Microneutralization (MN) testing of these samples, but they are considerably more resource intensive and technically demanding. HI titers also tend to fall faster than MN titers, and may drop below the positive cutoff within the span of a couple of years, which means that HI assays may miss older infections.  

With those limitations in mind, the authors found samples meeting the study's HI thresholds were 4.43% for H5N6 and 4.39% for H9N2, with lower rates for H7N9 (2.74%), H3N8 (1.44%), H5N8 (1.27%) and H10N3 (0.26%). 

First the link and abstract from the open-access study, after which I'll return with a postscript:

2018–2025 Serological study on avian influenza among occupationally exposed populations in the Poyang Lake area — the region with the highest environmental surveillance positive rate in China

Research Open access
Published: 14 October 2026 Cite this article
 
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Chuang Nie, Yawei Li,Wenjing Xie, Ke Qian, Ting Xu, Fenglan He, Zhiqiang Deng, Wanting Wei, Yujie Hou, Xiang Tu, Tianxin Xiang & Wentao Song

We’re sharing this article early to provide faster access to peer-reviewed, accepted research. It is citable and carries a permanent DOI. This version is subject to further edits and will be replaced automatically by the final Version of Record. All legal disclaimers apply.

Abstract

Background

An avian influenza virus positivity rate as high as 82.3% has been reported in Jiangxi Province, China, underscoring this region as a potential hotspot for avian influenza virus circulation. As a crucial hub for migratory birds and a region where wild birds, domestic poultry, and humans frequently overlap, Poyang Lake provides favorable ecological conditions for cross-species transmission of avian influenza viruses. This study aimed to describe the seroprevalence of antibodies against selected avian influenza virus subtypes among occupationally exposed populations at surveillance sites around Poyang Lake from 2018 to 2025, and to provide data to inform ongoing surveillance and risk assessment.

Methods

A cross-sectional serological surveillance was conducted annually during winter and spring from 2018 to 2025 in Nanchang County (Nanchang) and Duchang and Wuning Counties (Jiujiang), Jiangxi Province. Serum samples were collected from occupationally exposed individuals, including backyard poultry keepers and their household members and live poultry market workers with direct poultry contact.

Hemagglutination inhibition assays were performed by the National Influenza Center to assess antibody reactivity against the test antigens representing H5N6, H9N2, H7N9, H3N8, H10N3, H5N8, and H5N1. Predefined HI positivity thresholds were ≥ 1:20 for H3N8, H5N8, H5N1, H7N9, and H10N3 and ≥ 1:40 for H5N6 and H9N2.

Results

A total of 2,437 valid serum samples were analyzed (1,599 from Jiujiang and 838 from Nanchang). Overall, 108 samples (4.43%) met the predefined HI positivity threshold for H5N6, and 107 (4.39%) met the threshold for H9N2. During 2018–2020, 25 of 914 samples (2.74%) met the threshold for H7N9.

During 2021–2025, 22 of 1,523 samples (1.44%) met the threshold for H3N8, including 9 of 100 samples (9.00%) collected in Nanchang in the 2024 surveillance year. Four of 1,523 samples (0.26%) met the threshold for H10N3; all four were from Jiujiang in the 2024 surveillance year. Four of 314 samples (1.27%) met the threshold for H5N8 in 2020. None of the 600 samples tested for H5N1 in the 2024 and 2025 surveillance years met the predefined threshold.

Conclusions

HI antibody reactivity varied across subtypes, surveillance locations, and years among occupationally exposed participants around Poyang Lake. The H3N8 finding in Nanchang and the H10N3 finding in Jiujiang in the 2024 surveillance year warrant further investigation. H5N6 peaks in Jiujiang in 2021 and in Nanchang in 2022; H9N2 peaks in 2021 in Jiujiang and 2023 in Nanchang. HI reactivity alone does not establish subtype-specific human infection or local virus circulation. Continued serological surveillance, interpreted alongside poultry and environmental virological data, may inform risk assessment.

        (Continue . . . ) 

We've previously looked at a number of human seroprevalence studies which have also suggested more human spillovers occur than have been reported, including:

• 2024's Nature Preprint: Serological Analysis in Humans in Malaysian Borneo Suggests Prior Exposure to H5 Avian Influenza despite no human  infections reported in the region. 

• 2018's J. Infect & Public Health: High Seroprevalence Of Avian Influenza H9 Among Poultry Professionals In Pakistan which found > 50% of 332 participants tested showed reactivity to H9.

• 2016's JID: High Seroprevalence Of H5N1 Antibodies In Indonesian Poultry Workers found 84% of sera tested positive

• In 2012, in H5N1 Seroprevalence Among Jiangsu Province Poultry Workers, we saw a study that found across three locations tested (Gaochun, Jianhu and Gaoyou counties) the percentage of workers testing positive ranged from zero (Gaochun) to 5.38% (95%CI, 2.19%–10.78%) in Gaoyou.

The good news is, this strongly suggests the 50% CFR (Case fatality rate) of H5N1 is badly overstated, since many mild infections are never counted.  

Conversely, it also suggests that novel flu infections may occur far more often than previously thought, which increases the risks of viral adaptation to a human host, and provides additional opportunities for novel/seasonal coinfection, which could lead to a reassortment. 

Either way, this is a reminder that a lot more goes on with the evolution and spread of novel flu viruses than our limited surveillance might suggest.

BMJ Public Health (Review): Public health risks and control measures associated with live animal and animal product trade in traditional food markets in low- and middle-income countries

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In the summer of 2025 we looked at a review article (see J. Virology: Zoonotic Disease Risk at Traditional Food Markets) by Frida E. Sparaciari, Cadhla Firth, Erik A. Karlsson, and Paul F. Horwood which concluded that traditional food markets (TFMs) provide essential community services (both economic and social), but they can also be hotspots for zoonotic disease transmission.

 

Live bird markets (LBMs) have long been linked to human exposure to (and infection by) avian influenza viruses, so much so that in 2014, in CDC: Risk Factors Involved With H7N9 Infection, we looked at a case-control study that pretty much nailed visiting LBMs as the prime risk factor for infection.

Four years ago, in Zoonoses & Public Health: Aerosol Exposure of Live Bird Market Workers to Viable Influenza A/H5N1 and A/H9N2 Viruses, Cambodia, we looked at a study that documented high levels of H5 & H9 viruses in the air at a Cambodian LBM during the `high season' for avian flu, and more importantly, that a large percentage remained viable (and infectious).

In low and middle-income countries (LMICs) - where home refrigeration is less common - the ability to buy freshly killed poultry is often viewed as a necessity. 

Larger, more modern cities like Hong Kong have gone to great lengths to regulate and restrict live bird markets, while early in 2025, Shanghai suspended Live Poultry Sales altogether.

During past avian flu outbreaks - when authorities ordered LBMs closed - clandestine and unregulated markets sometimes sprang up, which only exacerbated the problem.

The authors of the above mentioned J.Virology review are back today (with several other contributors) with a follow-up scoping review based on 87 studies published between 2017 and the end of 2025 that reported on public health outcomes, risk factors or control measures associated with TFMs in LMICs.

Most of these studies centered on TFMs in China and Bangladesh, and while avian flu was the primary focus, other public health risks (primarily bacterial zoonoses, e.g. Campylobacter spp, Salmonella spp, and multi-drug resistant E. coli) were also considered.

While the authors offer up a number of suggestions that may help reduce the risks, this is a complex and varied problem, and solutions will likely have to be tailored to each TFM.   

Follow the link to read the review in its entirety. 

Public health risks and control measures associated with live animal and animal product trade in traditional food markets in low- and middle-income countries: a scoping review

Author affiliations• Frida E Sparaciari1 2,  Alfonso I Vargas Huaco3 4,  Charifa Zemouri5,  Anna Signe Fomsgaard1 2, Wei Ning Chen3 4, Cadhla Firth2 6, Paul F Horwood2 7, Erik Karlsson1 8

        BMJ Public Health 2026;4:e006159. doi:10.1136/bmjph-2026-006159 

Abstract

Introduction 

Traditional food markets (TFMs) support food security and livelihoods in low- and middle-income countries (LMICs), but the trade of live animals and products of animal origin may facilitate zoonotic and foodborne disease transmission. Evidence on associated risks and control measures remains fragmented across pathogens, market types and interventions. This scoping review maps the literature on zoonotic and foodborne public health risks, risk factors and control measures related to the trade of live animals and animal products in TFMs in LMICs.

Methods 

Web of Science, PubMed and Scopus were searched on 24 April 2026 for primary, English-language studies published from 1 January 2017 to 31 December 2025. Eligible studies reported public health outcomes, risk factors or control measures associated with TFMs in LMICs. Reviewers screened titles/abstracts and full texts against predefined criteria, resolving disagreements by consensus. Data were charted and checked using a standardised pro forma; no methodological quality appraisal was conducted.

Results 

87 studies were included; 61 (70.1%) reported public health risks and 35 (40.2%) examined control measures, with 9 (10.3%) addressing both domains. Most studies were observational and focused on poultry markets and avian influenza viruses (AIVs), particularly at the human–market interface. Reported risks included occupational exposure among market workers, exposure among community members and contamination of animal products and market environments.

Common risk factors included poor hygiene, weak biosecurity, on-site slaughter, species mixing, inadequate waste management, prolonged animal holding and unsafe handling. Control measures included market closure, rest days, species separation, cleaning and disinfection, infrastructure improvements and policy-based interventions such as China’s ‘1110’ policy.

Across distinct studies, several measures were associated with lower pathogen detection or modelled infection estimates, whereas other findings were non-significant or inconsistent. Implementation was constrained by economic losses, limited infrastructure, weak enforcement, low awareness and poor adherence to protective practices.

Conclusions 

TFMs are important human–animal–environment interfaces where zoonotic and foodborne risks arise from interacting biological, structural and behavioural factors. The findings from this scoping review provide a rationale for context-specific, multilevel One Health approaches combining infrastructure improvements, biosecurity, surveillance, regulation, compensation and vendor engagement. However, because most evidence was observational and concentrated on AIV-focused poultry markets, the effectiveness and generalisability of these approaches require further evaluation across diverse TFM settings. 

What is already known on this topic

Traditional food markets are essential to food access and livelihoods in many low- and middle-income countries, but the trade of live animals and products of animal origin can create human–animal–environment interfaces where zoonotic and foodborne pathogens circulate. Existing evidence remains fragmented and is largely concentrated on avian influenza in poultry markets.

What this study adds

This scoping review maps 87 studies and uses a One Health framework to integrate evidence on public health risks, exposure pathways, human health outcomes and control-measure implementation in traditional food markets. It shows that risk is produced by interacting market infrastructure, hygiene, biosecurity, animal management and human practices, rather than by live animals or animal-origin products alone.

How this study might affect research, practice or policy

The findings suggest potential value in adaptive, context-specific One Health approaches rather than isolated technical controls. Policy and research should evaluate combinations of infrastructure, water, sanitation and hygiene, biosecurity, surveillance, vendor engagement, market regulation and livelihood-sensitive incentives, while expanding evaluation beyond avian influenza virus-focused poultry systems.  

        (Continue . . . )

  

Preprint: Human Infection with Avian Influenza A(H7N7) Virus, Taiwan, 2026

 

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Last April 2nd, in Taiwan CDC: Human Infection with a Novel H7 Avian Virus, we looked at a lengthy report on Taiwan's first detection of a locally acquired human H7 LPAI infection in a poultry farmer.

The patient (a man reportedly in his 70s) was hospitalized with fever on March 22nd and subsequently developed pneumonia. He remained hospitalized and in isolation in early April, although his condition was said to be improving. 

The CDC also reported:

Currently, 33 close contacts are under health monitoring and management, and 3 have been given preventative medication based on risk assessment. Tests were conducted on 6 family members, all of whom tested negative.

The following day, we saw another Taiwan CDC Update: Novel H7 Infection Identified as H7N7.  We also saw a letter to physicians posted on April 8th.  At that time only the HA (H7) has been identified, with additional tests still pending.

We looked at a follow-up statement in early May (see Taiwan CDC: Statement/Update On Locally Acquired H7N7 Infection) after additional testing revealed the virus's PB2 gene carried the E627K mutation (PB2 E627K).

PB2-627K - which can often develop after a human/mammal is infected - is associated with enhanced replication and pathogenicity in mammals (see A rapid review of the avian influenza PB2 E627K mutation in human infection studies).

Yesterday an unusually terse (the abstract run just 50 words) preprint was posted on the medRxiv server which fills in some of the gaps on this event. 

We learn that virus (A/Taiwan/1/2026) was a low-pathogenic H7N7 bird flu virus from the wild-bird gene pool of Eurasia. The authors wrote:

Although the HA and M genes clustered with an A/environment/Kagoshima/KU-24-D10/2024(H7N7)-like virus isolated in Japan, the other gene segments were most closely related to different source viruses. Across the genome, 138A/Taiwan/1/2026 is distantly related to previously detected viruses from Taiwan and to reported human H7 viruses from China, Europe, and North America. 

The authors stated this suggests a recent spillover from a wild bird gene pool, as the virus is distinct from earlier H7N7 poultry viruses which have spilled over into humans. 

While it carried the PB2 E627K mammalian-adaptation marker, the authors cannot say whether that mutation was present in the bird host or arose post-infection in the patient (although the latter is suspected). 

Although no avian influenza virus was reported to have been detected in the duck farms visited by the patient, the authors suggest:

Based on the patient's occupation background, domestic ducks at the workplace may have served as an intermediate source of infection after introduction of the virus into Taiwan by migratory birds. However, direct exposure to migratory birds or their feces could not be excluded. 

None of the contacts tested showed serological evidence of infection. 

Follow the link to read the preprint in its entirety.  I'll return after the break with a postscript.

Human Infection with Avian Influenza A(H7N7) Virus, Taiwan, 2026

Yao-Tsun Li, Yun-Tong Lin, Bao-Shan Chen, Chuan-Yi Kuo, Hsiang-Yi Huang, Hui-Ying Ko, Pei-Yu Huang, Gavin JD Smith, Yi-Ling Lin, Ming-Tsan Liu
doi: https://doi.org/10.64898/2026.10.09.26365013
This article is a preprint and has not been certified by peer review [what does this mean?].  
 

Preview PDF

Abstract

Low pathogenic avian influenza A(H7N7) virus detected in a poultry worker in Taiwan, 2026 was related to viruses circulating in Asian wild birds and possessed PB2 E627K, a mammalian adaptation marker. Enhanced surveillance for H7 viruses in poultry and rapid characterization of human cases are essential to assess pandemic potential.

        (Continue . . . ) 

While H5Nx gets most of our attention these days, H7 viruses have a fairly impressive track record of their own.

• In 2003, the Netherlands saw an outbreak of H7N7 that resulted in the loss of 30 million birds across 1,000 farms, and saw scores of mild human infections and the death of a veterinarian (see Eurosurveillance Human-to-human transmission of avian influenza A/H7N7, The Netherlands, 2003).

• Another analysis, performed by the RIVM (Ministry of Health) found the spread of the virus to be much greater than originally reported, citing as many as 1,000 human infections (see Executive summary Avian Flu Epidemic 2003: Public health consequences).

• Smaller H7 outbreaks, including the 2004 H7N3 outbreak in British Columbia, a small number of human infections in Wales in 2007, and 3 mild cases in Italy in 2013 (see ECDC : Human Infection By Avian H7N7 In Italy) were also reported.

• But the 5-year epidemic of H7N9 in China (2013-2018) - which hospitalized more than 1,500 people, killing roughly 40% of them - demonstrate just how formidable an H7 virus can be.

NYC's 2016 dramatic H7N2 outbreak in hundreds of cats, and spillover into animal shelter workers (see J Infect Dis: Serological Evidence Of H7N2 Infection Among Animal Shelter Workers, NYC 2016) - and a 2018 report of a severe H7N4 infection out of China - further illustrate the risks.

Of the 27 novel influenza viruses ranked by the CDC using their IRAT tool, H7 viruses make up 2 of the top 5 (in terms of emergence), and rank higher (in terms of impact) than any of the H5Nx viruses listed. 

Which is why we continue to follow these cases with considerable interest.