CFIA Update On H5N1 In a B.C. Ostrich Farm: First Report of Genotype D1.3 in Canada

WOAH/OIE 
 

#18,740

Last December an ostrich farm in British Columbia reported unusual mortality among their birds, and in early January HPAI H5N1 was confirmed by the CFIA. 

That agency order culling - the long-standing  recommendation of WOAH/OIE (see below) - of the remainder of the exposed birds.

Control strategies and compensation for farmers

When an infection is detected in poultry, a policy of culling infected animals and the ones in close contact is normally used in an effort to rapidly contain, control and eradicate the disease.

Selective elimination of infected poultry, movement restrictions, improved hygiene and biosecurity, and appropriate surveillance should result in a significant decrease of viral contamination of the environment. These measures should be taken whether or not vaccination is part of the overall strategy. 

The farm owners have fought a protracted legal battle to prevent this culling, which has become a cause célèbre online, and in the political arena.  

Yesterday the CFIA published an update which adds a new wrinkle to this 5-month saga; the announcement that (at least some of) these ostriches were infected with a novel genotype (D1.3), which was identified in a sick Ohio poultry worker last February. 

Although more than 100 genotypes of H5N1 have been reported in North America since the H5 virus arrived in late 2021, over the past 15 months we've seen 4 new genotypes of note emerge in the United States and Canada.

• B3.13 aka the `bovine' strain affecting dairy cattle in at least 16 states and mildly infecting dozens of humans
• D1.1   a wild bird/poultry strain which has spilled over into > a dozen people in Washington State, severely infected a teenager in British Columbia, and produced a fatal infection in Louisiana. 
• D1.2  a wild bird/poultry strain which recently detected in poultry and 2 pigs in Oregon
• D1.3  a recently detected wild bird/poultry strain which has been infection poultry and at least 1 human

While we are only hearing about it 5 months after-the-fact, this first reported outbreak of genotype D1.3 in Western Canada pre-dates the Ohio outbreak by a couple of months.

While much of this announcement centers on the government's case for culling these birds, what arguably should have been the lede (in red) is buried about 1/3rd  the way down the page. 

Update on the Canadian Food Inspection Agency's actions at an HPAI infected premise at a British Columbia ostrich farm

From: Canadian Food Inspection Agency

Statement

The Canadian Food Inspection Agency (CFIA) and Canada's national poultry sectors have been responding to detections of highly pathogenic avian influenza (HPAI) in Canada since December 2021. Industry has been highly supportive of the CFIA in its response to HPAI, working collaboratively to implement control measures and protect animal health.

The CFIA has acted to minimize the risk of the virus spreading within Canadian flocks and to other animals. All avian influenza viruses, particularly H5 and H7 viruses, have the potential to infect mammals, including humans. Our disease response aims to protect public and animal health, minimize impacts on the domestic poultry industry, and the Canadian economy.

The CFIA's response to highly pathogenic avian influenza in domestic poultry is based on an approach known as “stamping-out”, as defined by the World Organisation for Animal Health (WOAH) Terrestrial Animal Health Code. Stamping-out is the internationally recognized standard and is a primary tool to manage the spread of HPAI and mitigate risks to animal and human health as well as enable international trade. It includes steps to eliminate the virus from an infected premises, including the humane depopulation and disposal of infected animals, and disinfection of premises.

There are ongoing risks to animal and human health and Canada’s export market access

Allowing a domestic poultry flock known to be exposed to HPAI to remain alive means a potential source of the virus persists. It increases the risk of reassortment or mutation of the virus, particularly with birds raised in open pasture where there is ongoing exposure to wildlife.

CFIA’s National Centre for Foreign Animal Disease (NCFAD) identified that the current HPAI infection in these ostriches is a novel reassortment not seen elsewhere in Canada. This assortment includes the D1.3 genotype, which has been associated with a human infection in a poultry worker in Ohio.

A human case of H5N1 in BC earlier this year required critical care, and an extended hospital stay for the patient, and there have been a number of human cases in the United States, including a fatality.

Stamping-out and primary control zones enable international trade as it allows Canada to contain outbreaks within a specific area, meet the requirements of zoning arrangements with trading partners, and permit Canada’s poultry industry to export from disease-free regions. Continued export market access supports Canadian families and poultry farmers whose livelihoods depend on maintaining international market access for $1.75 billion in exports.

Current status of the infected premise at Universal Ostrich Farm

Universal Ostrich Farm has not cooperated with the requirements set out under the Health of Animals Act including failure to report the initial cases of illness and deaths to the CFIA and failure to adhere to quarantine orders. Universal Ostrich Farm was issued two notices of violations with penalty, totaling $20,000.

The farm also failed to undertake appropriate biosecurity risk mitigation measures such as limiting wild bird access to the ostriches, controlling water flow from the quarantine zone to other parts of the farm, or improving fencing. These actions significantly increase the risk of disease transmission and reflect a disregard for regulatory compliance and animal health standards.

Universal Ostrich Farm has not substantiated their claims of scientific research. CFIA has not received any evidence of scientific research being done at the infected premises.

Research documentation was not provided during the review of their request for exemption from the disposal order based on unique genetics or during the judicial review process. Further, the current physical facilities at their location are not suitable for controlled research activities or trials.

On May 13, 2025, the Federal court dismissed both of Universal Ostrich Farm’s applications for judicial review. The interlocutory injunction pausing the implementation of the disposal order was also vacated.

Following the May 13 court ruling, the farm owners and supporters have been at the farm in an apparent attempt to prevent the CFIA from carrying out its operations at the infected premises. This has delayed a timely and appropriate response to the HPAI infected premises, resulting in ongoing health risks to animals and humans.

CFIA’s next steps at the infected premises

Given that the flock has had multiple laboratory-confirmed cases of H5N1 and the ongoing serious risks for animal and human health, and trade, the CFIA continues planning for humane depopulation with veterinary oversight at the infected premises.

The CFIA takes the responsibility to protect the health of animals and Canadians extremely seriously as we conduct these necessary disease control measures to protect public health and minimize the economic impact on Canada's poultry industry.

For more detailed information on the CFIA’s continued response to HPAI at this infected premises, please visit our website.

Understanding the origins and spread of novel genotypes, subtypes, and certain mutations in HPAI viruses are all critical if we hope to get some kind of control over  this growing epizootic.  

Last April Canada was singled out for being one of  the slowest nations in releasing non-human HPAI sequence information (see Nature: Lengthy Delays in H5N1 Genome Submissions to GISAID). 

Today's belated announcement only appears to further cement that reputation. 

OFID: Viral Families with Pandemic Potential

 

#18,739

For many years it was common to hear that - of all the diseases with pandemic potential - it was influenza A that kept virologists up at night.  A little over 20 years ago, the emergence of SARS-CoV forced the addition of novel coronaviruses to that short list. 

In 2017 (and again in 2018) the WHO released a list (n=8) of priority diseases (see WHO List Of Blueprint Priority Diseases) - that in their estimation had the potential to spark a public health emergency and were in dire need of accelerated research:

• Crimean-Congo haemorrhagic fever (CCHF)
• Ebola virus disease and Marburg virus disease
• Lassa fever
• Middle East respiratory syndrome coronavirus (MERS-CoV) and Severe Acute Respiratory Syndrome (SARS)
• Nipah and henipaviral diseases
• Rift Valley fever (RVF)
• Zika
• Disease X

Last summer the WHO unveiled an expanded 38-page Pathogens Prioritization report, increasing the number of priority pathogens to more than 30. Additions included 7 different influenza A subtypes (H1, H3, H3, H5, H6, H7, and H10), and 5 bacterial strains that cause cholera, plague, dysentery, diarrhea and pneumonia.

Thirty years ago researcher George Armelagos of Emory University posited that since the mid-1970s the world had entered into an age of newly emerging infectious diseases, re-emerging diseases and a rise in antimicrobial resistant pathogens (see The Third Epidemiological Transition (Revisited). 

And the following timeline, from the UK HAIRS group would seem to support that theory.

UK HAIRS Timeline - 20 years of Emerging Viruses

Nature, it seems, has a nearly inexhaustible supply of replacement viral contenders (see mBio: A Strategy To Estimate The Number Of Undiscovered Viruses), and what doesn't succeed today can always mutate and try again tomorrow. 

Today we've a perspective, published in Open Forum Infectious Diseases, by two well known infectious disease experts (Amesh Adalja, MD FIDSA & Thomas Inglesby, MD) from Johns Hopkins Center for Health Security, that proposes - in addition to Influenza A and Coronaviruses - that 4 other viral families be considered as having significant pandemic potential. 

• Picornaviridae     (e.g. rhinoviruses, EV-71, EV-D68, etc)
• Paramyxoviridae (e.g. HPIV, Nipah, measles, etc.)
• Adenoviridae        (e.g. Ad14, Ad7)
• Pneumoviridae     (e.g. Metapneumovirus, hRSV, etc.) 

Although there are certainly other viral families with pandemic potential, the authors of this perspective focus on viruses which currently have limited or no medical countermeasures (MCMs).  While it's not a long article, I've only posted a few excerpts.

Follow the link to read it in its entirety.  I'll have a bit more after the break. 

Viral Families with Pandemic Potential

Open Access
Amesh Adalja, MD FIDSA , Thomas Inglesby, MD
Open Forum Infectious Diseases, ofaf306, https://doi.org/10.1093/ofid/ofaf306

Published: 26 May 2025 Article history

A major challenge of pandemic preparedness is how to anticipate and prepare for future pandemic threats among the wide range of viral threats that can infect humans. Fortunately, only a subset of the 25 viral families that can infect humans have both the capability of widespread respiratory transmission in humans or animals, a prerequisite for pandemic-causing capability, as well a lack of medical countermeasures (MCMs) to prevent and treat the key viral species within them. 

Orthopoxviruses, for example, clearly have historically shown the capacity to cause terrible pandemics in humans, but there exist vaccines and antivirals that have been developed and stockpiled for this viral family that are cross protective against multiple family members (unlike the case for the pandemic-causing orthomyxoviruses and coronaviruses). 

Therefore, for the purposes of identifying novel rapid-onset novel pandemics, they are not listed here as a viral family of pandemic potential with unmet R&D requirements though there is clear need for improved countermeasures to both of these viral families. 

Prior to COVID, most pandemic preparedness efforts, when they did occur, focused almost exclusively on influenza viruses. Pandemic preparedness was considered to be nearly synonymous with influenza preparedness. This has basis in experience as the only occurring pandemics for almost a century (spanning from at least 1918 to 2009) were all caused by influenza A viruses. However, a number of events of the past 20 years have shown the capacity of coronaviridae to cause major epidemics and pandemics: SARS—CoV-1 in 2003, MERS-CoV in 2012, and, most recently and obviously, SARS-CoV-2 in 2019-2020.

It is critical now to plan for other viral threats that can cause huge epidemics or pandemics. We were one of the first to publish on the characteristics of pandemic pathogens, and in that effort, we emphasized conceptualizing the problem by putting specific focus on viral families of  greatest pandemic potential, particularly families for which no MCMs were yet developed [1,2]. 

          (Continue . . . )

Over the years we've looked at dozens of threats from these four viral families, including:

• EID Journal: Henipavirus in Northern Short-Tailed Shrew, Alabama, USA
• EID Journal: Emerging Enterovirus A71 Subgenogroup B5 Causing Severe Hand, Foot, and Mouth Disease, Vietnam, 2023
• India: Media Reports Of A Large Surge In Pediatric Adenovirus Infections 
• NEJM: A Novel Henipavirus With Human Spillover In China
• mBio: Contemporary EV-D68 Strains Have Acquired The Ability To Infect Human Neuronal Cells

While it's true that the vast majority of  these viruses will never fulminate into any kind of global health threat, COVID-19 showed it only takes one overachiever to plunge the world into chaos.  

Although severe pandemics were once thought to come along every few decades, recent studies suggest that the frequency, and impact, of pandemics are only expected to increase in the years ahead.

BMJ Global: Historical Trends Demonstrate a Pattern of Increasingly Frequent & Severe Zoonotic Spillover Events

PNAS Research: Intensity and Frequency of Extreme Novel Epidemics

Which means that while we can try to ignore these threats, at some point time our luck - and time - will run out. 

Moderna Announcement: HHS Cancellation of HHS Late-Stage Contract To Provide mRNA H5 Vaccine

 

Credit ACIP/CDC

#18,738

Just over a year ago, in response to the detection of H5N1 in diary cattle, the HHS contracted with CSL Seqirus for 4.8 million doses of a cell-based, adjuvanted, H5 vaccine (using the Astrakhan H5 antigen); enough for about 2.4 million people.

As the H5 threat increased over the fall and winter months, last January the outgoing administration awarded Moderna a $590 Million Dollar Contract To Develop an mRNA H5N1 Vaccine.  Almost immediately, the incoming administration announced they would be reviewing that contract. 

Despite an excellent safety record, and the added ability to produce large quantities of updated vaccine quickly without relying on antiquated egg-based manufacturing techniques - many people distrust mRNA vaccines; some vehemently. 

Admittedly, no vaccine is 100% or benign. With all medicines, there is a risk/benefit calculation to be made, and in most cases the benefits far outweigh any risks. 

Overnight Moderna posted the following announcement, providing an encouraging early update on  immune responses from the vaccine, followed by the HHS cancellation of the January contract. 

Moderna Announces Update on Investigational Pandemic Influenza Program

May 28, 2025

Phase 1/2 H5 avian flu vaccine study shows positive interim results

Company has been notified that HHS will terminate Moderna's award for late-stage development of pre-pandemic influenza vaccines

CAMBRIDGE, MA / ACCESS Newswire / May 28, 2025 / Moderna, Inc. (NASDAQ:MRNA) today announced positive interim data from a Phase 1/2 clinical study (NCT05972174) evaluating the safety and immunogenicity of its investigational pandemic influenza vaccine, mRNA-1018, in approximately 300 healthy adults aged 18 years and older. The interim results focus on a vaccine candidate targeting the H5 avian influenza virus subtype.

The Company had previously expected to advance the program to late-stage development with the U.S. Department of Health and Human Services (HHS); however, today Moderna received notice that HHS will terminate the award for the late-stage development and right to purchase pre-pandemic influenza vaccines.     

(SNIP)

The Phase 1/2 study evaluated a two-dose regimen of Moderna's investigational avian influenza vaccine. mRNA-1018 demonstrated a rapid, potent and durable immune response. At baseline, pre-existing immunity was minimal, with only 2.1% of participants showing hemagglutination inhibition (HAI) antibody titers ≥1:40, an HAI titer considered to correlate with protection. At Day 43, three weeks after the second vaccination, 97.8% of participants achieved titers ≥1:40 with a 44.5-fold increase of titers from baseline.

The investigational vaccine was generally well-tolerated, with no dose-limiting tolerability concerns observed. Most solicited adverse reactions were Grade 1 or 2 and did not increase significantly with number of doses or between first and second doses. Further data is expected to be submitted for presentation at an upcoming scientific meeting.

         (Continue . . . ) 

The production and deployment of emergency vaccines for a pandemic is often fraught with delays and uncertainty, which makes pre-planning all the more important.

Early experimental H5 (and H7) avian flu vaccines proved poorly immunogenic – requiring unusually large amounts of antigen (up to 12x normal). Adding an adjuvant - spread across two shots several weeks apart - produced a much better immune response (see 2015's JAMA: Immune Response Of H7N9 Vaccine With & Without Adjuvant).

The United States approved an adjuvanted monovalent H5Nx vaccine from Seqirus back in early 2020 (see FDA approval letters), despite concerns over whether Americans will accept an adjuvanted vaccine (which have been used successfully in Europe for years).

 

We've also seen difficulties in producing bulk H5N1 vaccines in the past, particularly in egg-based production facilities (see Manufacturing Pandemic Flu Vaccines: Easier Said Than Done).  And of course, because of our current poultry epizootic, the supply of eggs in which to make a vaccine could become a problem.

Even under the best reasonable scenario - using both egg and cell-based technology - it could take months into a pandemic before a vaccine would be widely available (see Maggie Fox's  SCI AM - A Bird Flu Vaccine Might Come Too Late to Save Us from H5N1). 

According to recent polls (see Two Surveys (UK & U.S.) Illustrating The Public's Lack of Concern Over Avian Flu), most people don't consider HPAI H5 to be a major public health threat.  And it is possible they are right. H5Nx could certainly fizzle, or be overtaken by another threat. 

I only know that there are a lot of viral contenders out there, and another pandemic is inevitable.

And as we discussed in The Wrong Pandemic Lessons Learned, the world seems to be less well prepared today for another pandemic than we were a decade ago. 

While a course correction is badly needed, I fear we may not see one until the pandemic-after-next.

WHO DON: Global COVID Situation (May 28th, 2025)

 

#18,737

Over the past few weeks we've been seeing reports of increasing COVID activity, particularly in Asia, and three days ago we looked at a WHO Risk assessment on a recently emerged variant (see WHO TAG-VE Risk Assessment On COVID VUM (Variant Under Monitoring) NB.1.8.1) that is behind some of this surge.

As we've discussed ad nauseum over the past few years (see here, here, here, here, etc.), 90% of the world's nations no longer report COVID hospitalizations or deaths, making it very difficult to track changes in the evolution and behavior of new variants. 

Despite evidence that repeated COVID infections increase the risks of developing `long COVID', and other sequelae (see Brain, Behavior & Immunity: COVID-19 may Enduringly Impact Cognitive Performance and Brain Haemodynamics in Undergraduate Students), governments around the globe have opted to minimize the threat, in order to `move on' from the pandemic.

While the WHO still produces a monthly COVID-19 epidemiological report, today they've published an unusual post-pandemic DON (Disease Outbreak News) update on the global COVID situation. 

The rub is, they cite `very limited data' submitted by member countries as preventing them from being able to fully evaluate the impact of this new wave. 

Despite these challenges, the WHO states the `global public health risk associated with COVID-19 remains high'.

I've only posted some excerpts from the report, so follow the link to read it in its entirety.   I'll have a postscript after the break. 

COVID-19 - Global Situation
28 May 2025

Situation at a glance 

Since mid-February 2025, according to data available from sentinel sites, global SARS-CoV-2 activity has been increasing, with the test positivity rate reaching 11%, levels that have not been observed since July 2024. This rise is primarily observed in countries in the Eastern Mediterranean, South-East Asia, and Western Pacific regions.

Since early 2025, global SARS-CoV-2 variant trends have slightly shifted. Circulation of LP.8.1 has been declining, and reporting of NB.1.8.1, a Variant Under Monitoring (VUM), is increasing, reaching 10.7% of global sequences reported as of mid-May. Recent increases in SARS-CoV-2 activity are broadly consistent with levels observed during the same period last year, however, there still lacks a clear seasonality in SARS-CoV-2 circulation, and surveillance is limited. Continued monitoring is essential. WHO advises all Member States to continue applying a risk-based, integrated approach to managing COVID-19 as outlined in the Director-General’s Standing Recommendations [1]. As part of comprehensive COVID-19 control programmes, vaccination remains a key intervention for preventing severe disease and death from COVID-19, particularly among at risk groups. 

Description of the situation

There has been an increase in SARS-CoV-2 activity globally, based on SARS-CoV-2 data reported to the Global Influenza Surveillance and Response System (GISRS) from sentinel surveillance sites. As of 11 May 2025, the test positivity rate is 11% across 73 reporting countries, areas and territories. This level matches the peak observed in July 2024 (12% from 99 countries) and marks a rise from 2% reported by 110 countries back in mid-February 2025 (Figure 1). The increase in test positivity rate is mainly being driven by countries in the Eastern Mediterranean Region, the South-East Asia Region, and the Western Pacific Region.

Countries in the African Region, European Region, and the Region of the Americas are currently reporting low levels of SARS-CoV-2 activity with percent positivity from sentinel or systematic virological surveillance sites ranging from 2% to 3%. However, some areas—particularly in the Caribbean and Andean subregions in the Region of the Americas showed increasing trends of SARS-CoV-2 test positivity as of 11 May. Publicly available wastewater monitoring data from countries in the European Region and the Northern America subregion remain low and, at present, do not indicate any upward trend in SARS-CoV-2 activity as of 11 May 2025.

The reporting of COVID-19 associated hospitalizations, Intensive Care Unit (ICU) admissions, and deaths is very limited from the countries in the Eastern Mediterranean Region, the South-East Asia Region, and the Western Pacific Region and does not allow for evaluation of the impact on health systems by WHO.

          (SNIP)

WHO risk assessment

As per the latest WHO global risk assessment, covering the period July-December 2024, the global public health risk associated with COVID-19 remains high. There has been evidence of decreasing impact on human health throughout 2023 and 2024 compared to 2020-2023, driven mainly by: 1) high levels of population immunity, achieved through infection, vaccination, or both; 2) similar virulence of currently circulating JN.1 sublineages of the SARS-CoV-2 virus as compared with previously circulating Omicron sublineages; and 3) the availability of diagnostic tests and improved clinical case management.

SARS-CoV-2 circulation nevertheless continues at considerable levels in many areas, as indicated in regional trends, without any established seasonality and with unpredictable evolutionary patterns. WHO produces global COVID-19 risk assessments every six months; the global risk assessment covering the period January-June 2025 is currently under development.

WHO continues to monitor emerging SARS-CoV-2 variants and undertakes risk evaluation for designated variants of interest (VOI) and VUMs with the support of the Technical Advisory Group of Virus Evolution (TAG-VE). Evaluation of the currently predominant VUM, LP.8.1, and the most recently designated VUM, NB.1.8.1, suggests no increased public health risk posed by these variants compared to other circulating variants.

To permit robust COVID-19 risk assessment and management, WHO reiterates its recommendations to Member States to continue to monitor and report SARS-CoV-2 activity and burden, public health and healthcare system impacts of COVID-19, strengthen genomic sequencing capacity and reporting, in particular information on SARS-CoV-2 variants [6], promptly and transparently to support global public health efforts.

          (Continue . . . )

While predicting what COVID will do next is a mug's game, we do know that COVID `immunity' - whether acquired from vaccines or infection - wanes over time, and vaccine uptake has continued to fall both here in the United States, and in many countries around the globe.

A summer surge is certainly possible.  And even if this latest variant proves to be no more virulent than previous Omicron strains, repeated infections are problematic. 

Which is why I got my 6-month COVID booster in April, and why I'll continue to wear an N95 mask in crowded, indoor, venues.  Neither guarantee I'll stay infection free, but they do improve my chances. 

Cambodia Reports 4th Fatal H5N1 Case Of 2025

#18,736

After going nearly a decade without a reported case, over the past 27 months Cambodia has reported 20 cases, with 4 cases (all fatal) reported since the first of the year.  The vast majority of cases have been in adolescents, children, and toddlers. 

Unlike from the milder 2.3.4.4b clade circulating in the United States, Europe, and much of the rest of the world, recent cases in Cambodia and Vietnam have stemmed from a resurgent older, and more virulent, clade (formerly clade 2.3.2.1c but recently redubbed as 2.3.2.1e).

 

Of these 20 Cambodia cases reported since early 2023, only 4 have been in adults and 3 of them survived. Among the 16 children and adolescents infected - while several had mild symptoms - most were severe and half (n=8) have died.

Once again, today's case comes after reports of numerous poultry deaths in a village. 

I've posted a screenshot from the Cambodian Facebook page announcing the case, and an English translation.  I'll have a brief postscript after the break.

          (translation)

Kingdom of Cambodia

Nation Religion King

Ministry of Health

Press Release

On

Bird flu death in 11-year-old boy

The Ministry of Health of the Kingdom of Cambodia would like to inform the public that there is 1 case of bird flu in an 11-year-old boy who was confirmed positive for the H5N1 avian influenza virus by the Pasteur Institute of Cambodia on May 27, 2025, residing in Srey Sampoung village, My Kraing commune, Samrong Tong district, Kampong Speu province. Despite the care and rescue efforts of the medical team, the child died on May 27, 2025 due to the cause of death on arrival at the hospital in a very serious condition, including fever, cough, shortness of breath and severe difficulty breathing. Investigations revealed that chickens and ducks near the patient’s house had been sick and dying for a week before the child started feeling sick.

The emergency response team of the national and sub-national ministries of health has been collaborating with the provincial agriculture departments and local authorities at all levels to actively investigate the outbreak of bird flu and respond according to technical methods and protocols, continue to search for sources of transmission in both animals and humans, and continue to search for suspected cases and contacts to prevent further transmission to others in the community, as well as distribute Tamiflu to close contacts and conduct health education campaigns for citizens in the affected villages.

The Ministry of Health would like to remind all citizens to always pay attention to and be vigilant about bird flu because H5N1 bird flu continues to threaten the health of our citizens. We would also like to inform you that if you have a fever, cough, sputum discharge, or difficulty breathing and have a history of contact with sick or dead chickens or ducks within 14 days before the start of the symptoms, do not go to gatherings or crowded places and seek consultation and treatment at the nearest health center or hospital immediately. Avoid delaying this, which puts you at high risk of eventual death.

How it is transmitted: H5N1 bird flu is a type of flu that is usually spread from sick birds to other birds, but it can sometimes be spread from birds to humans through close contact with sick or dead birds. Bird flu in humans is a serious illness that requires prompt hospital treatment.

Although it is not easily transmitted from person to person, if it can mutate, it can be contagious, just like the seasonal flu.

How to prevent:

• Do not touch or eat sick or dead chickens and ducks. Wear gloves and a mask or cover your nose with a scarf before handling chickens for food. Then blanch them in boiling water before plucking their feathers.
• Adhere to hygiene practices, wash hands frequently before handling food, especially after touching animals, cleaning poultry feathers, or other objects that may be sources of contamination.
• Cook food thoroughly before eating, especially meat, poultry, and eggs. Do not eat raw or undercooked eggs, and keep raw and cooked foods separate. Clean cooking utensils properly.
• If there are many sick or dead chickens at home or in the village and they have symptoms of fever, cough, sputum discharge, or difficulty breathing, please urgently seek consultation and treatment at the nearest health center or hospital to avoid delay, which puts you at high risk of eventual death.
• Therefore, the public is requested to be aware and take care of their health in the above preventive measures. The Ministry of Health will continue to provide information regarding public health issues on the Ministry of Health's official social media channels, as well as the official Facebook page of the Department of Communicable Disease Control and the website www.cdcmoh.gov.kh.

For more information, please contact the Ministry of Health's emergency hotline number 115 toll-free.

While the reasons behind this sudden resurgence of H5N1 in Cambodia are probably many and varied, a 2023 study (see Preprint: A Timely Survey of Knowledge, Attitudes, and Practices Related to Avian Influenza (H5N1) in Rural, Cambodia) found very lax attitudes regarding avian flu among the rural population.

The sharing, and cooking, of sick or dying poultry is something we've seen reported previously with these outbreaks, and was a major risk cited by that study.  The authors noted:

• Cambodia's higher-risk behaviors or vulnerability groups need priority intervention to reduce infectious and zoonotic diseases.

• Furthermore, we noticed that 23% of participants cooked sick or dead poultries for their families. 

• This study found that 49% reported poultry illness and deaths to local authorities.

Although the clade 2.3.2.1x H5N1 virus appears to be currently geographically limited to the Cambodia, Vietnam, Laos regions of Southeast Asia, we've seen reports suggesting it continues to reassort with the newer clade 2.3.4.4b virus (see FAO Statement On Reassortment Between H5N1 Clade 2.3.4.4b & Clade 2.3.2.1c Viruses In Mekong Delta Region).

Making this emerging clade one very much worthy of our attention.

Preprint: Novel Highly Pathogenic Avian Influenza (A)H5N1 Triple Reassortant in Argentina, 2025

 

#18,735

The superpower of influenza A viruses is their ability for different subtypes to co-infect a host, swap genetic material, and generate a new `hybrid' virus; a reassortant.  This reassortment can generate new genotypes, or - if the HA and NA are involved - a new subtype. 

Some influenza subtypes are more prone to reassortment than others, with LPAI H9N2 often cited as one of the most promiscuous viruses currently known.  HPAI H5 is another, and in the 3 years since its arrival to North America  more than 100 genotypes have been identified.

Most these genetic changes do little to change the behavior of the virus, but over the past 14 months we've seen 4 new genotypes of note emerge in the United States.

• B3.13 aka the `bovine' strain affecting dairy cattle in at least 18 states and mildly infecting dozens of humans
• D1.1  a wild bird/poultry strain which has spilled over into > a dozen people in Washington State, severely infected a teenager in British Columbia, and produced a fatal infection in Louisiana.  In 2025 it was detected in dairy cows in at least 2 states.
• D1.2  a wild bird/poultry strain which recently detected in poultry and 2 pigs in Oregon
• D1.3  a recently detected wild bird/poultry strain which has been infection poultry and at least 1 human

H5N1 made its way to the South American continent in late 2022, and over the next twelve months spread from Columbia to Argentina (and beyond) via migratory birds and marine mammals. 

While much of what occurs in remote regions of the world with H5N1 often flies beneath our radar, somewhat surprisingly we've seen little evidence of new reassortants coming out of South America. 

That is, until today, with the publication of the following preprint on the bioRxiv server which describes the detection of a South American reassortant H5N1 virus collected earlier this year at a mixed backyard flock in Chaco province, northern Argentina.  

I've reproduced the abstract, and have included a few excerpts from the full report.  Follow the link to read it in its entirety.  I'll have a brief postscript when you return.

Novel Highly Pathogenic Avian Influenza (A)H5N1 Triple Reassortant in Argentina, 2025
Ralph E.V. Vanstreels, Martha I. Nelson, Maria C. Artuso, Luana E. Piccini, Vanina D. Marchione, Estefania Benedetti,Alvin Crespo-Bellido, Agostina Pierdomenico, Thorsten Wolff, Uhart, eAgustina Rimondi
doi: https://doi.org/10.1101/2025.05.23.655175

          PDF  

Abstract

Genomic sequencing of re-emerging highly pathogenic avian influenza A(H5N1) virus detected in Argentina in February 2025 revealed novel triple-reassortant viruses containing gene segments from Eurasian H5N1 and low pathogenic viruses from South and North American lineages. These findings underscore continued evolution and diversification of clade 2.3.4.4b H5N1 in the Americas.

          (SNIP)

To our knowledge, this represents the first documented reassortment event between HPAI H5N1 and endemic South American LPAI viruses. The South American PB2 and PA segments are highly divergent from the rest of global AIV diversity (10) (Figure 1), suggesting that reassortment involving these genes has significantly expanded the genetic diversity of H5N1 polymerase segments.

Notably, although the H5N1-Arg_Feb2025 viruses have exchanged five gene segments, they retained the original Eurasian MP segment (Figure 2), which remains 100% conserved among H5N1 viruses circulating in North America. The absence of MP replacement by LPAI-derived segments, either in North or South America, suggests this MP segment may confer a selective advantage in HPAI H5 viruses.

Currently, there is no evidence of this novel 4:3:1 triple reassortant in other South American countries; however, should future detections confirm wider spread, classification as a new H5N1 genotype would be warranted.

           (SNIP)

In conclusion, our findings underscore the critical importance of sustained influenza surveillance coupled with whole-genome sequencing to track the evolution of HPAI H5N1 and support efforts to control and mitigate its impact on poultry, wildlife, and human health. Further research on the diversity of LPAI viruses circulating in Neotropical wildlife will be essential to understand potential interactions between H5N1 and South American lineage strains, and to assess the long-term consequences of the introduction of HPAI viruses into the region (and potentially beyond, should these reassortant strains spread to other regions). 

          (Continue . . . ) 

As the following FAO map (zoonotic avian flu reports since Oct 1, 2024) illustrates, reporting of avian influenza is pretty much limited to the United States, Southern Canada, Europe, and some parts of Southeast Asia. 

Vast swaths of Russia, China, South America, Africa and the Middle East rarely (if ever) report outbreaks, yet there is little doubt that (except for Australia/NZ) the virus is present in most of these non-reporting regions. 

We also learned last March - in Nature: Lengthy Delays in H5N1 Genome Submissions to GISAID - that the average delay for those countries which do submit non-human sequences to GISAID is 7 months, and that Canada came in last at 20 months.

A reminder that no news isn't necessarily good news - and given the limits of surveillance and reporting - we are always making decisions based on events that likely occurred weeks or even months ago. 

Two Cryptic Reports (WHO & HK CHP) Of An H5N1 Case In Guangxi, China

 Credit Wikipedia 

#18,734

When we get reports of novel flu cases out of China they are almost always belated, and usually devoid of much in the way of details.  Last week Hong Kong's CHP reported bare details on 1 New H10N3 Case & 8 H9N2 Cases from the Mainland.

This morning, Hong Kong's CHP has a very brief report in their weekly avian influenza report on a  recent H5N1 case in China's southern Guangxi Zhuang Autonomous Region. 

Since the previous issue of Avian Influenza Report (AIR), there was one new human case of avian influenza A(H5N1) from Guangxi Zhuang Autonomous Region, China reported by the World Health Organization (WHO) on 23 May 2025. From 2015 to 2024, 0 to 145 confirmed human cases of avian influenza A(H5N1) were reported to the WHO

While there is frustratingly little information provided here, on page 2 of the report we learn a little bit more the following chart:

The 53 y.o. female is listed as an imported case from Vietnam, and has reportedly recovered. 

Over the weekend the WHO WPRO (Western Pacific Regional Office) published their Avian Influenza Weekly Update # 998: 23 May 2025, and while it does not mention the patients age, gender, or supposed Vietnamese origin, it does add one additional detail; the patients discharge date (4/11/25) from the hospital.

Human infection with avian influenza A(H5N1) virus From 16 to 22 May 2025, one new case of human infection with avian influenza A(H5N1) virus was reported to WHO in the Western Pacific Region. The new case was reported from Guangxi Autonomous Region, China. The case was recovered and discharged on 11 April 2025.

Missing from both reports are crucial details on the patient's likely exposure, course of illness, treatment, contacts, and the clade of the virus (clades 2.3.4.4b & Clade 2.3.2.1e have both been recently reported in Vietnam). 

Official reports of novel flu outbreaks and infections from China (and increasingly, from elsewhere in the world) are often delayed for weeks and sometimes months - or are `sanitized' for political or economic reasons (see From Here To Impunity).

While we could go decades before the the next great global public health crisis emerges, with our current limited surveillance and dysfunctional sharing of information, it could start tomorrow and we might not know about it for weeks. 

WHO TAG-VE Risk Assessment On COVID VUM (Variant Under Monitoring) NB.1.8.1

#18,733

The most recent CDC Nowcast (see above) indicates that COVID variant LP.8.1 is currently responsible for nearly 3/4ths of the COVID cases identified in the United States, but that another variant - XFC - is making some solid inroads.  

Even with limited surveillance, at least 13 other variants are known to be circulating in the United States.  Around the globe, COVID's diversity is even greater. 

COVID continues to evolve a furious rate - both in humans and in non-human species - and many more COVID variants are expected to continue to come off the evolutionary assembly line going forward. While we've not seen any huge changes in its behavior since the arrival of the Omicron lineage in late 2021, there are no guarantees that can't happen again. 

Far fewer people are getting COVID boosters these days, and most people have abandoned masks and other NPIs to prevent infection, believing the risks of severe illness to be low. 

Still, the virus claims hundreds of American lives every week, and studies continue to find persistent and often severe sequelae linked to COVID infection (see Brain, Behavior & Immunity: COVID-19 may Enduringly Impact Cognitive Performance and Brain Haemodynamics in Undergraduate Students).

Over the past few weeks there have been numerous media reports of a surge in COVID cases in China, Hong Kong, and Taiwan much of which has been attributed to an emerging NB.1.8.1 variant (see CBS News  U.S. reports cases of new COVID variant NB.1.8.1 behind surge in China).

Meanwhile, Hong Kong's most recent (May 22nd) COVID report indicates their largest surge in severe and/or fatal COVID cases in nearly a year.  

Other, far less reliable reporting (often from China's dissident press) paint a more dire picture.  The reality is, anything - good or bad - we hear out of China has to be taken with a very large grain of salt.  But it is fair to say their is a surge in COVID cases, and deaths, in Asia right now.

Since the virus is continually evolving, and most people now eschew the booster shots, our collective immunity wanes a little bit more each day.  New surges in COVID are all but inevitable going forward. 

This morning we have a recently released risk assessment on NB.1.8.1 variant from the WHO's TAG-VE (Technical Advisory Group on SARS-CoV-2 Virus Evolution), which currently - and based on limited information - puts the risk from this emerging subvariant as `Low'. 

I've included some excerpts from a far more detailed report, follow the link to read it in its entirety.  I'll have a brief postscript after the break. 

WHO TAG-VE Risk Evaluation for SARS-CoV-2 Variant Under Monitoring: NB.1.8.1

Executive Summary

NB.1.8.1 has been designated a SARS-CoV-2 variant under monitoring (VUM) with increasing proportions globally, while LP.8.1 is starting to decline. Considering the available evidence, the additional public health risk posed by NB.1.8.1 is evaluated as low at the global level. Currently approved COVID-19 vaccines are expected to remain effective to this variant against symptomatic and severe disease. Despite a concurrent increase in cases and hospitalizations in some countries where NB.1.8.1 is widespread, current data do not indicate thatthis variant leads to more severe illness than other variants in circulation.

Initial Risk Evaluation of NB.1.8.1, 23 May 2025

NB.1.8.1 is a SARS-CoV-2 variant derived from the recombinant variant XDV.1.5.1, with the earliest sample collected on 22 January 2025. NB.1.8.1 is one of six VUMs tracked by the WHO and was designated as a VUM on 23 May 2025 [1,2]. In comparison to the currently dominant SARS-CoV-2 variant, LP.8.1, NB.1.8.1 has the following additional Spike mutations: T22N, F59S, G184S, A435S, V445H, and T478I. When compared to JN.1, NB.1.8.1 has the following mutations: T22N, F59S, G184S, A435S, L455S; F456L, T478I, and Q493E.

Spike mutations at position 445 have been shown to enhance binding affinity to hACE2, which could increase the variant’s transmissibility, mutations at position 435 shown to reduce the neutralisation potency of class 1 and class 1/4 antibodies [3], and mutations at position 478 shown to enhance the evasion of Class 1/2 antibodies [4]. 

Using pseudoviruses and plasma from BA.5 breakthrough infections with JN.1 or XDV+F456Linfection, NB.1.8.1 showed 1.5–1.6-fold reduction in neutralization compared to LP.8.1.1 [4]. In mice previously immunized with SARS-CoV-2 variants, further immunisation using monovalent KP.2 or monovalent LP.8.1  mRNA vaccines elicited similar or modestly lower neutralising antibody titres against NB.1.8.1 than those elicited by immunising KP.2 or LP.8.1 antigens [5,6].

As of 18 May 2025, there were 518 NB.1.8.1 sequences submitted to GISAID [7] from 22 countries, representing 10.7% of the globally available sequences in epidemiological week 17 of 2025 (21 to 27 April 2025). While still low numbers, this is a significant rise in prevalence from 2.5% four weeks prior in epidemiological week 14 of 2025 (31 March to 6 April 2025), Table 1. 

Between epidemiological weeks 14 and 17 of 2025, NB.1.8.1 increased in prevalence in all the three WHO regions that are consistently sharing SARSCoV-2 sequences, i.e. an increase from 8.9% to 11.7% for the Western Pacific region (WPR), from 1.6% to 4.9% for the Region of the Americas (AMR), and from 1.0% to 6.0% for the European Region (EUR). There are only 5 NB.1.8.1 sequences from the South East Asia Region (SEAR), and none from the from the African Region (AFR) and the East Mediterranean Region (EMR).

          (Continue . . . )

Since 90% of the world's countries no longer reliably report COVID statistics (hospitalizations, deaths, etc.), it becomes increasingly difficult to evaluate the impact of emerging COVID strains (see No News Is . . . Now Commonplace).

This WHO TAG-VE report bases its assessment on 3 criteria (see below), in all of which they cite only low confidence in the data. 

* Growth advantage Level of risk: Moderate, as NB.1.8.1 is growing substantially across all WHO regions with consistent SARSCoV-2 sequence data sharing. 

• Confidence: Low, as NB.1.8.1 expansion has only begun recently, there are low levels of sequencing data and therefore variant proportions exhibit spikes, and the variant has not been detected in some regions.

 ** Antibody escape Level of risk: Low, as the immune evasion of NB.1.8.1 in available data is of a similar magnitude to prior JN.1 sublineages upon their emergence. Additionally, NB.1.8.1 clusters with other JN.1 sublineages within antigenic cartography data based on sera from immunised mice.

• Confidence: Low, as NB.1.8.1 antigenicity has only been assessed in a single study using pseudoviruses with serological data from two cohorts. Additional laboratory studies using sera from different cohorts and regions are needed to further assess the risk of antibody escape. 

*** Severity and clinical considerations Level of risk: Low, as currently there are no reports of elevated disease severity associated with this variant. Available evidence doesn't suggest resistance to Nirmaltevir. 

• Confidence: Low. Currently there are no studies assessing the impact of this variant on clinical outcomes. Although, there is regular co-ordination and data sharing between all WHO Regional Offices, countries, and partners, reporting of new hospitalizations, ICU admission data with the WHO has been decreased substantially, therefore caution should be taken when interpreting trends in routine surveillance of severe cases. No studies have been conducted yet on the potential impact of the variant on the activity of antivirals like remdesivir and molnupiravir.

The global decision 2+ years ago to stop - or severely limit - the collection and sharing of COVID data may have been politically or economically expedient, but it has left us vulnerable to being blindsided by the next COVID variant of concern (VOC). 

Whether NB.1.8.1 or XEF, or some other as-yet-unknown variant has what it takes to plunge us back into another global crisis is unknown. 

But if not COVID, something will.  And with our current level of infectious disease denial, we are far from being ready to deal with it. 

WOAH: State of the World's Animal Health

 

#18,732

WOAH (the World Organization for Animals) released a 124-page PDF described as their `inaugural global overview of animal health' on Friday, May 23rd, which finds several animal diseases encroaching on new areas, with about half of them possessing some zoonotic potential. 

While there are some `human'  pathogens that don't appear to affect other species (smallpox being an example), many of the infectious diseases that affect humans originated in other species, and then spilled over into humans. 

Tuberculosis probably jumped to humans when we began to domesticate goats and cattle around 5000 years ago. Measles appears to have evolved from canine distemper and/or the Rinderpest virus of cattle.  And Influenza, which is native to aquatic birds, became much more of a threat after humans  domesticated ducks, geese, and chickens.

The list of zoonotic diseases is long and continues to expand, and includes such well known infections as SARS, MERS, SARS-CoV-2, Babesiosis, Borrelia (Lyme), Nipah, Hendra, Malaria, Dengue, Zika, Hantavirus, Monkeypox, Ebola, Bartonella, Leptospirosis, Q-Fever, multiple flavors of avian flu and many, many others.

In 2019 the CDC released a list of 56 zoonotic diseases of greatest concern for the United States (see chart below), with zoonotic (avian/swine/canine) influenza, emerging coronaviruses (e.g., SARS and MERS), Hantaviruses, Lassa Fever, Marburg/Ebola, and Monkeypox featured prominently. 

Not every animal disease of concern directly infects humans, as we've seen the substantial impacts of FMD, Classical Swine Fever and African Swine Fever, on local economies and food insecurity around the globe. 

As humans continue to encroach into previously uninhabited regions, and the trade and transport of animals increases around the globe, diseases that were once rare are now afforded new opportunities to expand their horizons. 

While not all-encompassing, the table of contents from the WOAH report provides a glimpse of its scope.

From their press release:

First report on world’s animal health reveals changing spread of disease impacting food security, trade and ecosystems

Published on 23 May 2025

Inaugural State of the World’s Animal Health report finds several animal diseases reaching new areas, with half of those reported able to jump to people.

Key findings:

•  Animal diseases are migrating into previously unaffected ​​areas, ​​half (47%) of which have zoonotic – or animal-to-human – potential. 

• Outbreaks of bird flu in mammals more than doubled last year compared to 2023, increasing the risk of further spread and human transmission. Access to livestock vaccines remains uneven around the world, with disease eradication efforts facing funding and political challenges.

•  Antibiotic use in animals fell by 5​​% between 2020 and 2022 and expanding livestock vaccination globally would reduce the risk of antibiotic resistance.

23 May, PARIS – Infectious animal diseases are affecting new areas and species, undermining global food security, human health and biodiversity, according to the first State of the World’s Animal Health report.

The new annual assessment, published by the World Organisation for Animal Health (WOAH), provides the first comprehensive review of animal disease trends, risks and challenges, from the uptake and availability of vaccines to the use of antibiotics in animals. Released ahead of WOAH’s 92nd General Session and its Animal Health Forum – where leading experts will gather to discuss vaccination and innovation in disease prevention – the report sets the stage for high-level discussions on how science-based vaccination strategies and emerging technologies can help address current and future animal health threats through a One Health approach.

Among its findings, the report revealed the reported number of avian influenza outbreaks in mammals more than doubled last year compared to 2023 with 1,022 outbreaks across 55 countries compared to 459 outbreaks in 2023.

The authors highlighted that, while the risk of human infection remains low, the more mammalian species such as cattle, cats or dogs infected, the greater the possibility of the virus adapting to mammal-to-mammal, and potentially human, transmission.

“The spread, prevalence and impact of infectious animal diseases is changing, bringing new challenges for agriculture and food security, human health and development, and natural ecosystems,” said Dr. Emmanuelle Soubeyran, Director General of WOAH.

         (Continue . . . ) 

The full document can be downloaded from:

https://www.woah.org/en/document/the-state-of-the-worlds-animal-health-2025/