Osterholm Podcast: The Potential Environmental (Airborne) Spread of H5N1

 

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Towards the end of the first world war French Prime Minister Clemenceau reportedly complained that  `generals are always preparing to fight the last war', and much the same could be said about the way we are currently trying to combat HPAI H5N1.  

The HPAI H5N1 clade 2.3.4.4b virus - which really only began its world tour a little  over 3 years ago - has demonstrated several new traits that set it apart from earlier versions of the H5 virus, including infecting a broader range of avian species, the unexpected spilling over into cattle, and producing severe neurological manifestations across a wide range of mammals. 

At the same time, we are seeing uncharacteristically mild illness in many (but not all) humans confirmed with the virus.  

The virus is spreading via migratory birds at a furious rate, and infecting large numbers of poultry operations.  Although most human infections have been linked to occupational exposure to poultry or cattle, the infectious source of a handful remain unknown.

And while currently the `official count' of cases in the United States is < 70 - given the limits of testing and surveillance - the real number is likely to be substantially higher (see Serologic Evidence of Recent Infection with HPAI A(H5) Virus Among Dairy Workers).

So far, we've attacked this current epizootic using pretty much the same tactics that have been used in the past, including during the (relatively brief) HPAI H5 epizootic of 2015.  

But that first battle was won largely because the virus wasn't yet `fit' enough to maintain itself in wild birds (see PNAS: The Enigma Of Disappearing HPAI H5 In North American Migratory Waterfowl), not because of our stellar control efforts. 

This time, we are dealing with a more persistent, more biologically `fit' virus; one that's become endemic in wild birds, and other hosts, in North America.  And the longer it remains in the environment, the more opportunities it will have to evolve and adapt. 

In this week's podcast, CIDRAP director Dr. Michael Osterholm discusses the very real possibility that the H5N1 virus may be carried by contaminated `dust' from poultry farms, infecting other nearby farms, animals, and potentially even humans.  

While this isn't a new idea (I'll have a review after the break), it has not exactly been universally embraced by the scientific community (see 2023's The Role of Airborne Particles in the Epidemiology of Clade 2.3.4.4b H5N1 High Pathogenicity Avian Influenza Virus in Commercial Poultry Production Units). 

This hour-long podcast covers a lot of subjects, including controversial changes ordered during the first week of the Trump administration, but this topic begins about 25 minutes into the podcast.  

A few excerpts from the transcript, but you'll want to listen to the full podcast. 

And if you've ever seen large numbers of migratory birds on farm fields, you can understand how much bird feces are produced and what that means. Now, I was involved in 2015 with H5N2 work, in which we had to depopulate a number of poultry barns here in Minnesota. I also was involved with a company that is the largest egg laying company in North America. And that work convinced me that what was happening was many of these poultry production facilities, whether they be for egg laying or for actual production of chickens for slaughter, that in fact, these barns have only slats, curtains that shut, so that in fact, that is the protection against cold weather. They're not airtight at all. Many times. The slats are open in warmer days and keep the birds from contact with other wildlife or in fact, wild birds.

Today, I am certain that we are seeing clouds of dust with bird feces in that, and we are beginning to see what I would consider to be almost an environmental type disease, similar to the transmission that we see with Coccidioidomycosis, what we call Valley fever, where in fact that's a fungus that grows in the environment. And then on windy days it blows with the dust and you inhale it. I think we're going to see the same thing with H5N1. That's why so many of these barns are now positive.

(SNIP)

The second thing is H5N1 is not going away. This is a brand-new type of virus activity within wild birds spilling over into domestic production and as well as into humans. I know that my description today of a world with lots of migratory waterfowl poop blowing in the wind with virus attached to it may not seem appealing to many, but I think it's real.

I think it's exactly what's happening. And we're going to see more human cases related to that. The poultry industry is doomed to have challenge after challenge if they don't change the way they house these birds. They're going to have to find a way to have airtight buildings with only HEPA filter air coming in the intake and HEPA filter air being sent out the backside. If that doesn't happen, I convince eggs are going to be an expensive commodity for a long time to come.

          (Continue . . . )

A number of times over the past 15 years we've looked at the world of aerobiology; the study of how bacteria, fungal spores, pollen and even viruses can be passively transported in the air.  

In 2010 (see Viruses Blowin’ In The Wind?)  we saw a report in the journal Environmental Health Perspectives, that suggested that it was possible for H5N1 (or any Influenza A virus) to be transported across long (hundreds of kilometers) distances in the air.

Although researchers demonstrated influenza RNA could be detected in ambient air samplings, they didn’t establish that the virus remained viable over long distances.

In December of 2012  (see Barnstorming Avian Flu Viruses?) we looked at a study in the Journal of Infectious Diseases called Genetic data provide evidence for wind-mediated transmission of highly pathogenic avian influenza that found patterns that suggested farm-to-farm spread of the 2003 H7N7 in the Netherlands due to the prevailing wind.

Another study of the same outbreak, Modelling the Wind-Borne Spread of Highly Pathogenic Avian Influenza Virus between Farms (PloS One 2012), found that wind borne transmission could have accounted for up to 24% of the transmission over distances up to 25 km. 

During the 2014-15 avian epizootic in the United States, airborne spread between farms miles apart was considered possible, although never conclusively proven see APHIS: Partial Epidemiology Report On HPAI H5 In The US) .

In Asia we've seen numerous instances where the `dust’ (desiccated chicken manure, feathers, etc.) from chicken farms has been strongly suspected as having spread bird flu – at least for a distance of several hundred yards. For some human bird flu cases in Indonesia and China, the only known exposure has been listed as living near, or simply walking past, a poultry farm or live market. 

While still controversial, since 2015 the notion of long-distance spread of viable viruses has gained additional traction. 

• In 2018, in Frontiers: Two Studies On The Epidemiology of Avian Influenza Viruses, we looked at a study that detected airborne HPAI viruses during the 2016-17 H5N8 epizootic in France, which saw more than 400 farms affected.  
• And in 2019, in Nature: Airborne Transmission May Have Played A Role In Spread Of U.S. 2015 HPAI Epizootic, we saw a study that looked at air movement trajectories and viral concentrations during the epizootic and the probability of airborne transmission for the 77 HPAI cases in Iowa. While not definitive, long-range airborne spread was considered plausible.

• And in 2022, in HPAI (H5N8) Clade 2.3.4.4b Virus in Dust Samples from Poultry Farms, France, 2021 - published in the CDC's EID Journal - we saw evidence of virus-contaminated dust on and around poultry farms, and suggests sampling the dust - instead of swabbing birds - may be a more effective way to detect avian influenza outbreaks.
• Also in 2022, in Zoonoses & Public Health: Aerosol Exposure of Live Bird Market Workers to Viable Influenza A/H5N1 and A/H9N2 Viruses, Cambodia, a study found that a `large percentage' of airborne viruses detected were viable. 

It isn't just avian flu. in 2020's study Nature Comms: Influenza A Transmission Via `Aerosolized Fomites', we looked at laboratory evidence that influenza A viruses (and probably others) can be transmitted via airborne or `aerosolized fomites'.

Whether H5N1 has the ability to spark a pandemic remains unknown, but even if it can't, it can still do tremendous damage to agricultural interests and to the economy. 

HPAI H5, along with many other emerging viruses, continue to surprise us. We either learn to adapt and adjust to their constant changes, or we literally risk being left in their dust. 

Referral: MedCram On Treating A Mild-to-Moderate Fever

 

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While the Internet is often a vast wasteland of dubious information, there are credible sources out there if you look hard enough. One that I rely on heavily is MedCram, which synthesizes important medical information (primarily for clinicians and medical students) into remarkably clear online lectures.

I've been a fan (and a subscriber) for years, and use it often just to bone up on medical topics I'm interested in. While they have a paid tier, they also have an extensive YouTube Channel with more than 1.5 million subscribers and over 550 of these presentations.

Yesterday Dr. Roger Seheult, MD presented a fascinating 22 minute lecture on `Why it's not always best practice to treat a fever.' A good deal of this lecture deals with a 2022 study on elevated body temperatures and the activation of the innate immune response (link below).

Body temperature variation controls pre-mRNA processing and transcription of antiviral genes and SARS-CoV-2 replication 

Bruna Los, Marco Preußner, Kathrin Eschke, Ricardo Martin Vidal, Azza Abdelgawad, Didrik Olofsson, Sandra Keiper, Margarida Paulo-Pedro, Alica Grindel, Stefan Meinke ... Show more

Nucleic Acids Research, Volume 50, Issue 12, 8 July 2022, Pages 6769–6785, https://doi.org/10.1093/nar/gkac513

Obviously, nothing in this blog should be construed as specific medical advice - as individual needs may differ - so everyone should consult their own doctor. But Dr. Seheult breaks down this study, and offers additional context, in the following video. I'll return with more after the break.

This, long-time readers will recall, is a debate we've visited numerous times in the past. Both in terms of treating fevers from viral infections, and fevers following vaccination.

• In 2010’s A Hot Topic For Further Research we saw a retrospective analysis in the Journal of the Royal Society of Medicine showing the risk of mortality increased by roughly 33% when antipyretics (aspirin, paracetamol, and diclofenac) were used in influenza infected (non-human) animals. 
• A year later, in A Feverish Debate, the Wellington based Medical Research Institute of New Zealand, published a paper (Antipyretic therapy for influenza infection—benefit or harm?) in the New Zealand Medical Journal that questioned the conventional wisdom of using these drugs with influenza.
• Also from 2011 - the American Academy of Pediatrics (AAP) released a report on the use of antipyretics in children, suggesting that we ought not over-treat fevers (Clinical Report—Fever and Antipyretic Use in Children)
• And in 2013,  in Adding To A Feverish Debate, we looked at a study in the Journal of Pediatrics on another possible (albeit, rare) adverse effect seen in a small number of young children with fever and dehydration at a hospital in Indiana who received treatment with NSAIDs -  AKI or Acute Kidney Injury.
• In 2016, French researchers released a study in the Journal of Pediatrics (Nonsteroidal Anti-Inflammatory Drug without Antibiotics for Acute Viral Infection Increases the Empyema Risk in Children: A Matched Case-Control Study), which found an increased risk of Empyema (bacterial lung infection) in children receiving NSAIDS for viral infections.

Fever is our body's way of combating a viral infection. By taking antipyretics, we not only produce a host environment conducive to better viral replication, it may allow someone who is still contagious to feel good enough go to work, or school, and further spread the virus.

Over the years we've seen some studies suggesting that taking analgesics following vaccination may blunt the recipient's immune response, but the evidence remains mixed. 

A little over a year ago, in No Evidence That Analgesic Use after COVID-19 Vaccination Negatively Impacts Antibody Responses, the authors even suggested promoting their use might improve uptake of booster immunizations.  Whether that applies across the board is unknown.

The Children's hospital of Philadelphia (CHOP) offers this advice:

What about medications for fever?

Should I give my child medication prior to a vaccine visit to prevent fever after vaccination?

No. Giving medication prior to a vaccine visit is not recommended because they may decrease the child’s immune response to the vaccine. Studies of patients who got fever-reducing medication prior to vaccination had lower antibody responses compared with patients that did not receive medicine, suggesting that their immune response to the vaccine was lower as a result of reducing the fever.

Should I give my child medication to treat a fever after vaccination or during illness?

In most cases a child does not need to be medicated for a fever unless they are extremely uncomfortable. The most important thing to do when a child has a fever is to make sure they stay hydrated by drinking plenty of fluids. If you are not sure whether the child should get medicine to address fever or other symptoms, talk to your child’s healthcare provider.

As always, if you are in doubt, consult your family healthcare provider.

Nature Reviews: The Threat of Avian Influenza H5N1 Looms Over Global Biodiversity

 

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While the threat of HPAI H5N1 in livestock - and sporadic spillovers into humans - have garnered most of our bird flu attentions this past year, there has been a massive, and underappreciated, impact on both avian and mammalian wildlife around the globe. 

Numbers are impossible to quantify, but hundreds of millions of wild birds have died, and hundreds of thousands - perhaps millions - of wild mammals have succumbed to the virus. 

A few past blogs on this carnage include:

Travel Med. & Inf. Dis.: Pacific and Atlantic Sea Lion Mortality Caused by HPAI A(H5N1) in South America

EID Journal: Recent Changes in Patterns of Mammal Infection with Highly Pathogenic Avian Influenza A(H5N1) Virus Worldwide

EID Journal: Mass Mortality of Sea Lions Caused by HPAI A(H5N1) Virus (Peru)

We've seen other avian flu viruses infect and kill marine mammals on a much smaller scale - including H3N8 in New England (2011), H10N8 in Germany (2014), and H5N8 in the Baltic Sea (2017) - but in early 2024 we saw a Research letter in the EID Journal  stating `. . . it seems likely that pinniped-to-pinniped transmission played a role in the spread of the mammal-adapted HPAI H5N1 viruses in the region.'

Simply put, the impact of HPAI H5Nx viruses is far greater than it was just 4 or 5 years ago, and is very likely to continue to evolve over time. While human infections remain thankfully rare, every spillover into a mammal provides the virus with another opportunity better adapt to human physiology.

But even if that never happens, the impact on our shared ecosystem - and the loss of hundreds of millions of birds and hundreds of thousands of mammals - is enormous and growing.

Last year we followed attempts to protect the endangered California Condor from HPAI H5N1, after more than 20 deaths were reported in the wild (see USFWS Update: 21 Condor Deaths Attributed To HPAI H5).  As scavenger birds, Condors feed almost exclusively on carrion, which increasingly runs the risk of being infected with HPAI H5 (see USDA Mammalian HPAI Infection List).

While the knock-on effects of HPAI's damage to wild birds and mammals are difficult to predict, it isn't hard to imagine what the loss of a half billion birds might have on the mosquito population in some regions - or the loss of scavenger birds on the efficient cleanup of carrion - both of which could adversely affect human health.

Last week Nature Reviews Biodiversity published a review by Sergio A. Lambertucci, Andrea Santangeli & Pablo I. Plaza on HPAI H5's threat to global biodiversity.  Both  Lambertucci and Plaza have been featured in this blog several times before (see here, here, and here). 

I've only reproduced a few excerpts, so follow the link to read this important review in its entirety.  I'll have a brief postscript after the break.

The threat of avian influenza H5N1 looms over global biodiversity

Sergio A. Lambertucci, Andrea Santangeli & Pablo I. Plaza

Nature Reviews Biodiversity volume 1, pages7–9 (2025) Cite this article

The highly pathogenic avian influenza H5N1 is an emerging and unexpected threat to many wild animal species, which has implications for ecological processes, ecosystem services and conservation of threatened species. International collaboration and information-sharing is essential for surveillance, early diagnosis and the provision of financial and technical instruments to enable worldwide actions.

As many wild animal populations are already under strain from habitat loss, climate change and other global change drivers, previously neglected threats such as some emerging infectious diseases can rapidly decimate wildlife populations1. One such emerging disease in wildlife is the highly pathogenic avian influenza caused by the A H5N1 virus.

(SNIP)

An estimated half a billion domestic fowl have died of H5N1 (ref. 4), and this number is rising; mortality in wildlife is more difficult to quantify than in poultry, but the effects are substantial. By mid-2024, H5N1 infections were documented in at least 406 bird and 51 mammal wild species (according to reports on the World Animal Health Information System (WAHIS)), and available reports suggest that multiple millions of wild animal individuals may have died (Fig. 1a).

The most noteworthy mass-mortality events include more than 200,000 wild birds in coastal areas of Peru6; 24,000 sea lions in South America7; 20,500 wild birds in Scotland8; 6,500 Cape cormorants in Namibia9; and 17,400 elephant seals, including >95% of the pups in Argentina10. These figures, however, largely underestimate actual mortalities, owing to a pervasive lack of monitoring, testing and reporting — particularly in inaccessible areas and in disadvantaged countries4,7.

(SNIP)

Apart from the intrinsic value of the wildlife being lost and the potential for concerning changes in ecosystem function, ecosystem services could be compromised by the loss of wildlife. For example, the loss of marine birds could result in lower availability of guano, an important source of fertilizer for some communities6,9. The potential ecological changes in marine coastal ecosystems15 could modify food and other provisioning services to local fishers or seaweed collectors. The service of ecotourism could be impaired by the loss of pinnipeds and marine birds (for example, penguins) in some regions, including Antarctica. Cultural services such as recreation, relaxation, leisure and spiritual enrichment could also be affected. Potential effects of ecosystem service losses should be assessed by scientists from the social and natural sciences together with Indigenous people, local communities and other stakeholders who are affected.

        (Continue . . . )

Eighteen months ago, in Avian Flu's New Normal: When the Extraordinary Becomes Ordinary, I wrote about the numbing effect that comes with the constant barrage of HPAI H5 reports from around the world.  

Events that were nearly unthinkable two or three years ago (e.g. Repeated trans-Atlantic introduction of avian flu from Europe, the spread of HPAI H5 across the length of South America, numerous spillovers of H5 into mammalian species, and the arrival of HPAI H5 to Antarctica) have now become `the new normal'.

Admittedly, for many it is easier to turn a blind eye to what is happening, as long at it doesn't affect them directly. But $10 for a dozen eggs may not be the worst fallout we'll see from this virus, 

We underestimate HPAI's threat at our own, considerable, peril.  

Georgia Reports 2nd Commercial HPAI H5 Poultry Outbreak

Georgia Largest Chicken Producer - Credit USDA
 

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On Saturday Georgia's Department of Agriculture announced that state's first outbreak in a commercial poultry flock, along with a suspension of all Poultry Exhibitions, Shows, Swaps, and Sales (etc.). 

Georgia is the largest producer of poultry in the nation. This from the USDA:

Georgia ranks as the top poultry production state in the nation. The industry employs more than 88,000 in the state and generates more than $4.3 billion in farm gate value and an overall annual economic impact to the state of more than $28 billion. Three out of four Georgia counties are involved in poultry and egg production.

Today Georgia has announced a second outbreak in Elbert County, Georgia, reportedly in close proximity to the first affected farm. 

Highly Pathogenic Avian Influenza Confirmed in 2nd Commercial Poultry Flock in Georgia

Atlanta, Ga – Today, the Georgia Department of Agriculture and the United States Department of Agriculture Animal & Plant Health Inspection Service (APHIS) confirmed a positive case of Highly Pathogenic Avian Influenza in a second commercial poultry flock in Elbert County, Georgia. This is the second detection of HPAI in a commercial poultry flock in Georgia, and the sixth detection overall since the nationwide outbreak began in 2022. While the current suspension of poultry activities remains in place, retail sales of poultry products like meat and eggs as well as poultry production and processing operations are not impacted by the suspension. More information on suspended activities is available here, and notifications will be issued when the suspension is lifted. The Department was notified of a second positive result by Georgia Poultry Lab Network on Friday, January 17th, 2025. That detection enabled GDA staff to initiate operations on the ground without waiting to receive additional confirmation from USDA’s National Veterinary Services Laboratory (NVSL). Additional confirmation through NVSL is needed before an HPAI event is publicly announced, and that confirmation was received from NVSL late in evening on January 21, 2025.
 
“HPAI remains a serious threat to our state’s economy, Georgia’s #1 industry, and the health and safety poultry in our state, and our team at the Georgia Department of Agriculture responded immediately to start depopulation, disposal, and cleaning & disinfecting operations,” said Agriculture Commissioner Tyler Harper. “The close proximity of the affected premises allowed our team to respond to both cases concurrently, and while those operations continue, our law enforcement officers are maintaining a secure perimeter to prevent further spread. I want to thank our team at the Georgia Department of Agriculture and our partners, who have been working 12+ hour days during a holiday weekend in the bitter cold to protect our state’s #1 industry and the farm families who fuel its success.”
 
On Friday, January 17th, 2025, samples that were collected from a commercial poultry operation for routine, premovement testing by the Georgia Poultry Lab Network returned a positive result for HPAI. On Tuesday, January 21, 2025, the HPAI positive result was confirmed by USDA’s National Veterinary Services Laboratory in Ames, Iowa. The premises, referred to as Elbert 02, is located approximately 210 yards away from Elbert 01, the initially affected location. Elbert 02 had approximately 130,000 broilers onsite. 
 
The Georgia Department of Agriculture’s Emergency Management & State Agricultural Response Team deployed immediately to the initially affected premises (Elbert 01) and expanded to include Elbert 02 to conduct depopulation, disposal, and cleaning and disinfecting operations. Operations occurred concurrently due to the close physical proximity and the positive detection at the Georgia Poultry Lab Network of the second location. Depopulation of Elbert 01 and Elbert 02 was completed in the initial 48 hours after detection. Disposal and cleaning & disinfecting operations are ongoing, and Georgia Department of Agriculture Law Enforcement officers continue to maintain a secure perimeter around the affected premises.
 
Animal disease response protocols require immediate action when HPAI is detected to successfully mitigate further spread of the disease. In the case of Elbert 02, a positive result from the Georgia Poultry Lab Network enabled the Georgia Department of Agriculture to initiate operations on the ground without waiting on confirmatory results from USDA’s National Veterinary Services Laboratory. However, further confirmation of HPAI by NVSL is needed prior to a case being announced publicly in Georgia. While NVSL testing will provide additional information on the HPAI virus involved in these cases, the additional information does not change the Department’s protocol and need to initiate an immediate response. 
 
All commercial poultry operations within a 10 Kilometer (6.2 mile) radius remain under quarantine and will continue to undergo increased surveillance testing for a period of at least two weeks. Given the close proximity of Elbert 01 and Elbert 02, an additional quarantine radius was not required and a permit from the Department is needed to move poultry and poultry products moving into, out of, and within the control area.  
 
The suspension of poultry activities for sales (auction market, flea market, or other livestock market), shows, swaps, meet ups, and exhibitions involving live birds remains in effect until further notice. Retail sales of poultry products like meat and eggs as well as poultry production and processing operations are not impacted by the suspension.

USDA Updates Mammalian Wildlife With HPAI H5 List

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Yesterday the USDA updated their HPAI H5 in wild mammals list, adding 8 more cases.  While many cases go unreported, since January 1st 2025, 25 new cases have been added; 16 domestic cats, 1 each (mountain lion, seal, & Serval) and 6 mice (3 deer mouse, 3 house mouse). 

The USDA only began tracking house cat infections 7 months ago (see May 2024's USDA Map Now Tracking Domestic Cats With H5N1), although a few older cases were added retrospectively.  Mice were first added a week later, in June (see USDA Adds House Mouse To Mammals Affected by H5N1).

The susceptibility of cats (both domestic and wild) to HPAI H5N1 has been long known (see 2015's HPAI H5: Catch As Cats Can), but the role that rodents may play in its ecology is less studied. 

• Last August, in Pathogens: Susceptibility of Synanthropic Rodents to H5N1 Subtype HPAI Viruses, we looked at a study where researchers challenged several rodent species (house mice, brown rat, black rat) with two (older 2010, 2007) HPAI H5N1 viruses, and found they are both susceptible to the virus and could potentially play a role it its evolution and spread.

• Also in August 2024, in Emer. Microbe & Inf.: HPAI Virus H5N1 clade 2.3.4.4b in Wild Rats in Egypt during 2023, we a surprisingly high percentage of wild rats testing positive for H5 antibodies in Egypt, suggesting that some number may survive the infection. 

So far the USDA lists 104 confirmed H5 infections in mice, 80 in house cats, and 63 more assorted wild felines (bobcats, mountain lions, tigers, etc.).  Combined, they make up more that 50% of all of the infected mammalian species on the USDA's list. 

That list is far from exhaustive, however, since many states have reported zero - or only a few - infections.  It would appear that some states may be looking harder that others. 

But even in states that are actively looking, testing and reporting is often limited by animals dying in remote and difficult to access places, or by animals that survive the infection. It is fair to say that what is reported is just the tip of the pyramid. 

In addition to rodents, we've recently seen a number of studies showing that shrews, voles, and other small (often peridomestic) mammals are susceptible to novel flu (see Virology: Susceptibilities & Viral Shedding of Peridomestic Wildlife Infected with Clade 2.3.4.4b HPAI Virus (H5N1)) 

Last summer, in  Nature: Decoding the RNA Viromes in Shrew Lungs Along the Eastern Coast of China, we looked at a study that found a wide range of zoonotic viruses - including HPAI H5N6 - in shrews. Previously, in 2015's Taking HPAI To The Bank (Vole), we looked at that species' susceptibility to both H5N1 and H7N1.

Not so very long ago, HPAI H5 was pretty much just an avian virus, with occasional spillovers to humans and cats unlucky enough to be fed a diet of raw chicken.  But starting in 2021 we began to see reports of numerous spillovers into a much wider range of mammals (see chart below).

Credit ECDC/EFSA

As the HPAI H5 virus continues to find new mammalian hosts it is likely to become more deeply entrenched in our shared ecology, increasing the risks that it will find new evolutionary pathways that were unavailable to it when it was primarily a disease of birds.

Where that takes us is anyone's guess, but it is unlikely that HPAI H5 will be going away anytime soon. 

Virginia: Richmond Zoo Reports Bird Deaths From HPAI H5

 

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We've another indication of the eastward movement of HPAI across the nation (see Saturday's Georgia Reports 1st Commercial HPAI H5 Poultry Outbreak) with the announcement yesterday from the Richmond Metro Zoo of two crane deaths due to HPAI H5N1.  

Last week Chicago's Lincoln Park Zoo Confirmed H5N1 Deaths in a Harbor Seal & Flamingo while last month we saw a zoo in Arizona (see Maricopa County Health Dept. Statement On H5 At Local Zoo) report the loss of a number of animals including a cheetah, mountain lion, swamphen, an Indian goose and a kookaburra.

Last week, we also saw a similar outbreak at the Nuremberg Tiergarten (Zoo) in Germany.  With migratory birds on the move around the globe, there is simply a lot of virus in the environment right now.

The statement from the Richmond Metro Zoo follows, after which I'll have a brief postscript:

Statement Regarding Positive Tests for H5 “Bird Flu” in Cranes

Jan 20, 2025


The Metro Richmond Zoo is partnering with the Virginia Department of Agriculture and Consumer Services (VDACS) and the Virginia Department of Health (VDH) to respond to and monitor positive tests for H5 bird flu in deceased cranes. The zoo remains open, and the public’s current risk of bird flu remains low.

A deceased crane tested positive for bird flu at VDACS laboratory on January 16. A second crane presumptively tested positive for bird flu. This is the first positive test of bird flu in the zoo’s 30-year history. The affected birds did not live in any of our aviaries where the public share a common space with birds.

The zoo is saddened by the loss of the cranes and our thoughts are with the zookeepers who cared for them. Our animal care team remains committed to providing the best care for our animals. We are taking precautions to keep our animals, staff, and guests safe and healthy.

VDACS has been on-site at the zoo to evaluate the need for additional testing and monitor the health of our other animals. VDH is conducting a public health response to complement the VDACS animal health response. VDH is monitoring the health of zoo staff who had close contact with the infected birds.

The bird flu is widespread in native, wild birds worldwide and can spread to domestic birds and other animals in human care. The current public health risk in the United States is low for H5 bird flu. Currently, there are no reports of H5 bird flu infections in people in Virginia.

Since the risk to the public is low, the zoo will continue to operate normally during the multi-agency investigation. Out of an abundance of caution, we have decided to temporarily close the budgie exhibit and walk-through bird aviary.

For more information, contact Brookie Crawford, Risk Communications Manager for the Virginia Department of Health, at brookie.crawford@vdh.virginia.gov.

Resources about H5 Bird Flu

Virginia Department of Health

There are currently multiple reports of wild bird deaths around the nation, including some calls to take down bird feeders.  Outbreaks in commercial poultry, which three months ago were mainly coming from Western states, have largely shifted east (see map below).

The H5 virus currently lacks the ability to transmit efficiently from human-to-human, but every new  mammalian infection is another opportunity for the virus to crack that code.

While the CDC continues to rank the risk to general public from avian flu as low, they do provide very specific guidance to pet owners on how to limit their risk of infection from the virus (see What Causes Bird Flu in Pets and Other Animals).

And given the reports of heightened virus activity across the nation, it is advice well worth heeding.