How H5N1 bird flu hid unrecognized for weeks in dairy cattle

Study reveals the biology of why the disease looked so different when it made the leap to cows, and offers a framework for spotting its next new guise more quickly

University of Pittsburgh

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Microscopic image of bovine mammary gland tissue showing influenza virus receptors (yellow) on mammary epithelial cells. The study identified receptor patterns that may help explain the susceptibility of the bovine mammary gland to H5N1 infection and its ability to support viral replication.

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Credit: Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh.

PITTSBURGH— When H5N1 bird flu first began infecting U.S. cattle in early 2024, diagnosis was elusive, because in cows, the disease looked completely different. Instead of affecting the lungs, as H5N1 does in other mammalian species, it caused severe infection in the cows' udders, largely sparing the lungs.  

A study by University of Pittsburgh School of Public Health researchers published today in Science Advances provides the first mechanistic explanation for this peculiar new guise for H5N1, which now affects more than 100 bird and mammal species globally. The study also establishes a new way to help scientists spot bird flu’s next surprise move more quickly, saving precious time in mounting public-health measures to stem the spread. 

The disease first appeared in dairy cattle along the Texas Panhandle as stubborn cases of severe, necrotizing mastitis, a painful inflammatory condition that damages tissues in the mammary glands.  

"Mastitis is a classic disease in milk-production animals, and veterinarians were dutifully looking to all the usual suspects for the source, like bacterial pathogens," said senior author Suresh Kuchipudi, Ph.D., chair of Infectious Diseases and Microbiology at Pitt Public Health. "When the real culprit turned out to be bird flu, everyone in the field was caught completely by surprise. We hadn't even remotely considered that cattle could be a host for H5N1.”  

In the weeks before the virus was identified, it moved from herd to herd, sickening the cattle—and contaminating their environments.  

"If a cow is infected, it sheds a lot of virus into the milk," said Kuchipudi. "This raised concerns about occupational risk for farm workers. Also, there is a habit of feeding raw milk to domestic pets, like cats, and there have been instances of cats dying, which we studied previously." He stressed that fortunately, pasteurization is effective at killing the virus, underlining the importance of avoiding raw milk. 

Kuchipudi has been studying influenza viruses for his entire career, with a particular focus on how receptor biology determines which species—and which tissues—can be infected. Typically, such studies involve staining cells for the presence of receptors that are known to work in a lock-and-key relationship with influenza, a subset of sugar-based molecules known as glycans.  

In initial studies by other groups, such experiments suggested that flu‑related glycan receptors were present in the noses, tracheas and lungs of cows. The fact that the animals were nonetheless not developing respiratory infections told the team there was more to the story.  

"Glycan biology is very complex," said Kuchipudi. "We realized that, to understand what was really going on, we would need to use more innovative technologies and map out the fine‑detailed architecture that enables the virus to bind to cells." Kuchipudi collaborated on the study with Harvard Medical School's Lauren E. Pepi, Ph.D., an expert in the methodology for comprehensively cataloging the entirety of glycan structures, dubbed glycomics.   

Using a multimodal approach that combined binding experiments, staining methods and ultra‑high‑resolution imaging, the team revealed that not all glycan receptors were functioning the same in animals infected with bird flu. Only a particular subtype, known as N‑linked sialic acid receptors, could bind to H5N1. These receptors were virtually absent in cow airway tissue, but pervasive in udders, making them a "perfect breeding ground for the virus," Kuchipudi said. 

The research provides a framework other scientists can use to potentially predict not just whether H5N1 can jump to new hosts, but also how.  

"We can preemptively screen different species and different tissues within them for susceptibility," said Kuchipudi. "For example, would they exhibit respiratory symptoms? Would they show only mastitis, as in cows? Or would they show neurological disease, as our team has shown in cats? The lessons learned could potentially help prevent us from being caught by surprise again."  

Other authors on the study were Surabhi Srinivas, M.S., Shubhada K. Chothe, Ph.D., Santhamani Ramasamy, Ph.D., Sougat Misra, Ph.D., Noel Chandan Nallipogu, M.D., MPH, and Lindsey LaBella, all of Pitt; Yin-Ting Yeh, Ph.D., of Pennsylvania State University; May Wang, B.S., of Harvard University; and Heidi L. Pecoraro, Ph.D., and Brett T. Webb Ph.D., of North Dakota State University. 

This research was supported by Pitt Public Health, and the U.S. Department of Agriculture's National Institute of Food and Agriculture (FP00039373/AWD00010780). 

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About the University of Pittsburgh School of Public Health  

Founded in 1948, the University of Pittsburgh School of Public Health is a top-ranked institution of seven academic departments partnering with stakeholders locally and globally to create, implement and disseminate innovative public health research and practice. With hands-on and high-tech instruction, Pitt Public Health trains a diverse community of students to become public health leaders who counter persistent population health problems and inequities.   

 

www.upmc.com/media 

---

Journal

Science Advances

DOI

10.1126/sciadv.aea2068 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Receptor Basis of Unusual Tissue Tropism of Avian Influenza H5N1 Clade 2.3.4.4b Virus in Cattle

Article Publication Date

19-Jun-2026

COI Statement

NA

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• How H5N1 bird flu hid unrecognized for weeks in dairy cattle
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Highly contagious bird flu found in Australia for the first time

20.06.2026, dpa

Photo: Richard Wainwright/AAP/dpa

By Rebekah Lyell, dpa

The highly contagious H5N1 bird flu virus has been detected in mainland Australia for the first time, authorities said on Saturday.

Agriculture Minister Julie Collins said a brown skua, a type of migratory seabird, found on a remote beach south of Perth in Western Australia had tested positive for the disease.

The positive result means the virus, which has infected millions of birds worldwide, had now spread to every continent.

"This is the highly pathogenic strain of concern that has been circulating globally, and this is its first detection on mainland Australia," Collins said.

There was no evidence of any mass mortalities nor any evidence of infection in any poultry, she said.

Samples from another sick bird from the same region had been tested and had returned a suspected positive result for the avian influenza. The samples had now been sent for confirmatory testing.

Prime Minister Anthony Albanese said the case was concerning, but the country was well prepared to respond.

"This is something that has happened through migratory birds, and has happened by definition around the world, and this is why we are preparing for this," he said.

Collins pointed to a A$100 million (US$70 million) government investment to prepare for a potential avian influenza outbreak.

"We have looked at what has happened overseas we have learnt from that, which is why we have invested early."

The H5 variant of avian flu was found on the sub-Antarctic remote Australian territory of Heard Island last year. The disease was detected on the island, about 4,000 kilometres south-west of Perth, after an unusually high number of elephant seals died there.

• Scimex on Australia confirmation
• Statement

(c) 2026 dpa Deutsche Presse Agentur GmbH

From Gas to Groceries, Rural Americans Paying Heaviest Price for Trump’s Iran War

A Center for American Progress analysis found that the war is “forcing rural households to pay at least $26 more per week at the pump and threatening to push grocery prices even higher in the months ahead.”


A worker fuels a tractor on a farm in Rocky Hill, Connecticut on April 2, 2026.
(Photo by Mark Mirko/Connecticut Public via Getty Images)

Brett Wilkins
May 15, 2026
COMMON DREAMS

President Donald Trump won the 2024 election largely on a promise to alleviate the affordability crisis, but an analysis published Friday underscores how rural Americans—the bedrock of the MAGA base—are disproportionately paying the price for the US-Israeli war of choice on Iran.

“Rising gas and fertilizer prices tied to the Trump administration’s war in Iran are driving up costs for rural families, farmers, and consumers across the country,” notes the analysis from the Center for American Progress (CAP), a liberal think tank.

“Gas prices rose 52% between February 27, the day before the war with Iran began, and May 14, forcing rural households to pay at least $26 more per week at the pump and threatening to push grocery prices even higher in the months ahead,” the publication continues.

“The economic fallout from the conflict is disproportionately affecting rural America, where households already spend significantly more on gasoline and energy and where farm operations depend heavily on diesel fuel and fertilizer,” CAP added. “As oil prices rise and shipping through the Strait of Hormuz remains disrupted, farmers are facing mounting input costs during an already difficult economic period.”

CAP researchers also found that the gap between urban and rural fuel costs has increased from $46 to $70 per month since the start of the war.

With diesel fuel accounting for over 60% of their fuel expenditures, farmers are facing the prospect of paying at least $350 more per day to operate a single tractor.

“There are 453 farming-dependent counties across the country, and rising fuel and fertilizer costs could force more small and medium-sized farms out of business if disruptions continue,” the analysis warns.

As Common Dreams reported this week, Trump’s illegal war of choice and erratic tariff policies are hurting farmers and consumers while Big Ag profits from fast-rising fertilizer and food prices.

Likewise, while consumers feel the pain of skyrocketing pump prices, Big Oil is reaping prodigious profits fueled by scarcity and market uncertainty due to the closure of the Strait of Hormuz and other war-related causes.

A report published earlier this month by the office of Sen. Ed Markey (D-Mass.) projects that US drivers could pay an additional $876 per year—or $1,753 for a family with two cars—on gasoline per year if pump prices remain at their current levels.

The CAP analysis comes on the heels of the latest consumer price index, released earlier this week, which revealed that inflation has risen to its highest level in three years largely due to rising fuel and food costs.

According to CAP, lower-income households—which spent a third of their pretax income on food in 2024—“will be hit hardest” by rising grocery prices, as the highest-income households spent just 6.4% of their before-tax earnings on food.

“Families in rural communities are already stretched thin, and this conflict is making everyday necessities even more expensive,” CAP senior fellow and analysis co-author Anne Knapke said Friday. “Higher gas prices, rising fertilizer costs, and more expensive groceries are all contributing to an affordability crisis that this president is making worse every day.”

Asked earlier this week if he thinks about the financial hardship his war is inflicting on Americans, Trump flippantly replied, “Not even a little bit.

Could High Fertilizer Prices Change the Face of Farming?

The development of agroecological and regenerative approaches would see a food system that is not only less vulnerable to the supply chain shocks being felt today, but would be better for the environment, human health, and animals.


Farmer Russell Hedrick prepares a blend of minerals, biologicals, and fertilizers to be sprayed onto his fields while they are being seeded in Hickory, North Carolina, on April 10, 2026.
(Photo by Grant Baldwin / AFP via Getty Images)

Frances Macguire
May 17, 2026

Common Dreams

The global disruptions caused by the war in Iran have brought renewed focus to the vulnerability of global fossil fuel supply chains. But what has received less attention is how the war also highlights the vulnerability of industrial agriculture supply chains reliant on massive amounts of chemical fertilizers and other inputs. Like oil and gas, these frequently travel long distances through turbulent waters.

A big advantage of renewable energy technologies like solar is that sunlight doesn’t have to pass through the Straits of Hormuz. The same can be said for many of the inputs required for agroecological and regenerative farming systems. The development of these approaches would see a food system that is not only less vulnerable to the supply chain shocks being felt today, but would be better for the environment, human health, and animals. It would be healthier, kinder, and more resilient.

A global economic recession and possible food shortages are looming as the war in Iran grinds on. While the devastating impact of the current conflict on people, their families, and communities must be foremost in our minds, the shock waves from the crisis are having system-wide impacts on energy supplies, cost of living, and food prices. As the seasons turn and farmers prepare to plant their crops, they are facing a new pressure: a sudden and critical rise in fertilizer and fuel costs.

As the price of petrol and diesel have skyrocketed since the closure of the Strait of Hormuz, so too have fertilizer costs due to shortages of urea and ammonia. A third of the world’s key fertilizer chemicals pass through the Strait, and prices have risen steeply since the outbreak of war, with predictions that prices for nitrogen-based fertilizers like urea could roughly double if the war drags on. Alongside a rise in red diesel prices, agricultural profit margins are highly volatile.

The current war is heinous, but inadvertently it has created an inflexion point, a moment to rethink global distribution of goods, and our broken food system.

Farmers taking the financial hit will likely pass on the costs to the consumer, but this isn’t sustainable and undermines the financial, social, and environmental health of the global food system. What if we flip it? Could the Middle East War not only accelerate a shift to renewable energy but also reduce our dependency on fertilizer-hungry crops? Legumes such as beans and peas, which fix nitrogen in soils, root vegetables, soybeans, and hardy grains such as rye could be viable alternatives.

Since the Second World War, a burgeoning (and hugely profitable for a few) chemical industry has created food systems dependent on inputs such as fossil fuel-based fertilizer, pesticides, herbicides, and fungicides. While delivering greater crop surplus, industrial farming has brought new problems: algal blooms, less wildlife and pollinators, monocultures, local air pollution, global climate change, and the loss of small-scale farming and farmers.

We’ve reached a tipping point; we overproduce food, a third of which is wasted, and too many people are eating too much of the wrong types of food. Noncommunicable diseases such as cardiovascular disease and diabetes are becoming a much bigger health burden than infectious diseases. Meanwhile, entrenched inequalities mean that, despite a global food surplus, millions of people go hungry every day, and 2.6 billion people can’t afford a healthy diet. An insatiable demand for meat now means that there are over 76 billion farmed chicken, pigs, and cattle in production around the planet, driving a largely invisible burden of animal suffering.

The current war is heinous, but inadvertently it has created an inflexion point, a moment to rethink global distribution of goods, and our broken food system. Growing crops that don’t need so many fossil fuel-derived chemicals but still provide enough food to feed our populations, and sustainable farming for current and future generations, is where we should be heading. We need to transition away from industrial agriculture, to food systems built on fairness—to people, animals, and the planet—not one geared toward feeding animals to feed ourselves. It’s a stark reality that over one-third of land used to grow arable crops is used to grow crops for animal feed.

Animal farming industry groups have been calling for public money to weather supply shocks, which begs the question of how resilient are the industrial systems we currently rely on. The US government provided $1 billion in response to avian flu, for example, while the European Union directed €46.7 million to Italian farmers, plus another €15 million for weather and animal-disease-related impacts in parts of Europe, and Canada extended livestock tax relief linked to bovine TB and extreme weather. The Food and Agricultural Organization of the United Nations (FAO) is also calling for urgent action in the form of government funds to protect the countries heavily exposed to import disruptions.

It’s clear that the current industrial animal farming model is not resilient. It depends heavily on unstable supply chains exposed to geopolitical shocks, climate change, extreme weather events, and disease outbreaks, and is a deeply inefficient use of plant resources to feed the world. Yet public money keeps being used to stabilize food systems that are structurally fragile, rather than directed toward sustainable and humane agriculture.

The current crisis in the Middle East has once again spotlighted our dependence on fossil fuels for energy and for food production. The growing success of renewable energy technologies—wind, solar, electric vehicles, and heat pumps—provides a roadmap to achieving energy independence at local and national levels. This has been achieved through several decades of policy and fiscal support, such as feed-in tariffs, technological advances, and growing public support.

Changing how we produce food could advance rapidly on the coat tails of our energy revolution. Calls for a just transition in farming and food production are growing from independent, small-scale farmers to development organizations, from Indigenous people’s groups to animal welfare charities. This transition would pivot away from destructive, insecure industrial agriculture toward more equitable, humane, and sustainable forms of agriculture, such as agroecology.

Rethinking food is not a nice to have, it’s essential if we are to strengthen the resilience of farmers, consumers, and nations, reducing exposure to geopolitical tensions, supply-chain disruptions, and future global shocks.


Our work is licensed under Creative Commons (CC BY-NC-ND 3.0). Feel free to republish and share widely.


Frances Macguire
Frances MacGuire is the director of research and animal welfare at World Animal Protection.
Full Bio >

Hantavirus contact person to be brought to Germany for testing

06.05.2026, DPA

Photo: Alexander Woelfl/SDMG/dpa

A person who came into contact with hantavirus on the Hondius cruise ship is to be brought to Dusseldorf for medical testing, a hospital in the western German city said on Wednesday. 

The University Hospital in Dusseldorf said the transportation and precautionary medical testing of the person would take place on Wednesday. It added that the person concerned is asymptomatic and presumed not to be infected with the virus. 

"This is a contact person with no confirmed evidence of a hantavirus infection. Admission is purely precautionary for medical evaluation," the hospital emphasized.

Three passengers of the Hondius - which is anchored off Cape Verde after sailing across the Atlantic from Argentina with just under 150 people on board - have died amid an outbreak of hantavirus. 

Another passenger has tested positive for the virus after returning to Switzerland.

According to the World Health Organization (WHO), three people suspected of having hantavirus have been evacuated from the cruise ship. WHO head Tedros Adhanom Ghebreyesus said they are on their way to receive medical treatment in the Netherlands.

It was initially unclear whether the person who is to be transported to Dusseldorf had been in contact with one of these three people. 

The WHO is working with the operators of the Hondius to closely monitor the health of passengers and crew and to arrange evacuations if necessary.  

"At this stage, the overall public health risk remains low," the WHO head wrote on X.

• Statement from ship operators
• German Health Ministry on Hantavirus, in German
• RKI report, in German
• Swiss Health Ministry's statement, in German
• WHO on X

(c) 2026 dpa Deutsche Presse Agentur GmbH

Human Spread Of Hantavirus Not Ruled Out On Cruise Ship

 May 6, 2026 

UN News

By Dominika Tomaszewska-Mortimer

Hantavirus victims on a ship in the Atlantic Ocean may have been infected prior to joining the cruise and human-to-human transmission on board cannot be ruled out – although it is rare – the World Health Organization (WHO) said on Tuesday.

The deadly disease outbreak has triggered an international public health response. Seven individuals of the 147 passengers and crew have been reported ill and three have died in what remains a fluid situation, WHO’s chief of Epidemic and Pandemic Preparedness and Prevention Dr Maria Van Kerkhove told reporters in Geneva.

“One patient is in intensive care in South Africa, although we understand that this patient is improving,” she said, while two patients still on board the ship, which is currently off the coast of Cabo Verde, are being prepared for medical evacuation to the Netherlands for treatment. 

Dr Van Kerkhove stressed that the situation is being closely monitored. As a precaution, passengers have been asked to remain in their cabins while disinfection and other public health measures are carried out. Medical teams from Cabo Verde are providing support on board the ship.

“The plan is, and our highest priority is, to medically evacuate these two individuals” to make sure that they receive the required care, she insisted. 

There are no other symptomatic patients on board. A third suspected case who reported a mild fever at one point “is currently doing well”, the WHO official said.

Spain cooperation

The ship is set to continue on to the Canary Islands. Ahead of arrival, Dr Van Kerkhove said that WHO is working with the Spanish authorities who “have said that they will welcome the ship to do a full epidemiologic investigation, full disinfection of the ship, and of course to assess the risk of the passengers”. 

Hantaviruses are carried by rodents and can cause severe disease in humans. Thousands of infections are estimated to occur each year. People usually get infected through contact with infected rodents or their urine, their droppings, or their sali

Discussing the suspected origins of the outbreak, Dr Van Kerkhove said that the initial patients, a husband and wife, boarded the boat in Argentina. 

“With the timing of the incubation period of hantavirus, which can be anywhere from one to six weeks, our assumption is that they were infected off the ship,” she said. “This was an expedition boat… many of the people on board were doing bird watching” and “seeing a lot of different wildlife.”

The cruise stopped at several islands off the coast of Africa, Dr Van Kerkhove continued, some of which “have a lot of rodents”. 

“There could be some source of infection on the islands as well for some of the other suspect cases,” she said. “However, we do believe that there may be some human-to-human transmission that’s happening among the really close contacts” such as the husband and wife and others who have shared cabins.

Past outbreak lessons

Transmission of infection between people is uncommon, but limited spread has been reported among close contacts in previous outbreaks of the Andes virus, which is part of the hantavirus group.

There are no specific treatments for hantavirus other than supportive care. 

“Typically, people will develop respiratory symptoms, so respiratory support is really important,” Dr Van Kerkhove said, stressing that some people require mechanical ventilation. Intensive care may be required, especially if the condition of patients deteriorates.

Directing her message at the people on the boat, where more than 20 nationalities are represented, the WHO official said: “We just want you to know we are working with the ship’s operators” and with the travellers’ countries of origin.

“We hear you. We know that you are scared,” she said. “We’re trying to make sure that the ship has as much information as they can…that you’re cared for and of course, that you get home safely.”

Hantavirus cruise highlights the environmental risks of ‘last chance tourism’, scientists warn

Copyright AP Photo/Mark Baker, File

By Ruth Wright with AP
Published on 06/05/2026 - EURONEWS

Trips to Antarctica “need to be regulated appropriately, as you would with any of the world’s sensitive and precious ecological sites,” says one expert.

Some of the most remote destinations on Earth are irreversibly melting away, giving rise to 'last chance tourism' - an industry built around the desire to see places like Antarctica before they disappear.

But a deadly outbreak of the rare hantavirus aboard a Dutch cruise ship has experts warning that tourists can inadvertently contaminate very fragile ecosystems.

Hantavirus is confirmed to have killed two people and suspected to have killed another onboard the MV Hondius, a cruise ship which left Argentina on 1 April and visited Antarctica and several isolated islands.

The ship has been at the centre of an international health scare since Saturday, after it was revealed that the rare disease, generally spread from infected rodents, was at the centre of an outbreak onboard the "ice-strengthened cruise ship".

The 107-metre polar explorer vessel is currently off the coast of Cape Verde, awaiting the evacuation of passengers who require medical attention. From there, the ship is hoping to sail to the Canary Islands but local authorities have not yet granted permission for the boat to dock there.

Health workers get off the Dutch-flagged MV Hondius, a cruise ship carrying nearly 150 people as it remains off Cape Verde on 4 May, 2026 Qasem Elhato via AP

The Antarctic Peninsula is one of the fastest-warming places in the world

Tourism to the bottom of the world is soaring. Experts warn that with more visitors comes an increased risk of contamination, illness and other damage to the continent.

While visitor numbers are still small – in part due to the high costs and time it can take – they are growing so fast that scientists and environmentalists are sounding alarms.

Most expeditions head to the Antarctic Peninsula, one of the fastest-warming places in the world. From 2002 to 2020, roughly 149 billion metric tons (164 billion tons) of Antarctic ice melted per year, according to the National Aeronautics and Space Administration.

A common route is to voyage south from Argentina toward Antarctica before heading north up the coast of Africa – the same route taken by the cruise ship MV Hondius.

Passengers walk inside the volcano at Deception Island in Antarctica, Wednesday, Nov. 26, 2025. AP Photo/Mark Baker, File

Bird flu has spread to Antarctica

Officials have not indicated any evidence of contamination from the MV Hondius.

However, flocks of migratory birds brought avian flu from South America to Antarctica in recent years, according to the US Centers for Disease Control and Prevention.

That outbreak prompted the International Association of Antarctica Tour Operators and others to harden rules for tourists’ conduct and hygiene to protect visitors from being contaminated.

To protect the fragile ecosystem from invasive species large and microscopic, visitors are told to stay away from animals and to avoid touching the ground with anything but their feet.

“There are rules that people are bound by when they’re heading south,” Nielsen said, describing her five voyages as a former guide. Crews and passengers use vacuums, disinfectants and brushes to scrub shoes and equipment clear of bugs, feathers, seeds and microbe-carrying dirt.

“Between the tongues and the laces of the boots you can find a lot of things,” she said.

Cruise ships have been struck by outbreaks of diseases like norovirus, which can spread quickly in a ship's close quarters. In 2020, a COVID-19 outbreak on the Diamond Princess turned the cruise ship into an incubator for the then-mysterious virus.

Hantavirus usually spreads by inhaling contaminated rodent droppings.
Explosive growth of trips to the southern continent

In 2024, more than 80,000 tourists touched down on the vast ice-cloaked continent and 36,000 viewed from the safety of ships, according to data collected by the International Association of Antarctica Tour Operators.

The International Union of Concerned Scientists estimates that tourism to Antarctica has grown tenfold in the past 30 years.

That number could rise further in the next decade as costs fall with more ice-capable hulls hitting the water and technological advances, says Hanne Nielsen, a senior lecturer of Antarctic law at the University of Tasmania. Her colleagues at the university estimate the annual figure could triple or quadruple to over 400,000 visits in that time.

The Hondius' island hopping cruise

WHO is investigating possible human-to-human transmission on the cruise ship, said Dr. Maria Van Kerkhove, WHO’s director of epidemic and pandemic preparedness. Officials suspect the first infected person likely contracted the virus before boarding, she said, and officials have been told there are no rats on board.

Antarctica is governed by the Antarctic Treaty, which in 1959 enshrined the territory as a scientific preserve used only for peaceful purposes. A series of rules that followed “aim to ensure that all visits, regardless of location, do not adversely impact the Antarctic environment or its scientific and aesthetic values,” according to the treaty’s secretariat.

Companies and scientific ventures voluntarily comply with biosecurity guidelines and submit environmental impact assessments for Antarctic operations.
RelatedCruises have doubled in size since 2000: NGO calls for €50 tax to stem ‘out of control’ emissions

The treaty was written when tourism numbers were much lower, Christian said.

“Activity needs to be regulated appropriately, as you would with any of the world’s sensitive and precious ecological sites,” Christian said from Hiroshima, Japan, where she was preparing for an Antarctic Treaty Consultative Meeting. There she'll join calls to strengthen protections for Antarctica's penguins, whales, seabirds, seals and krill — tiny creatures at the base of the food chain.

For now, the lure of the frozen frontier continues to draw visitors.

“You can put a footprint in Antarctica and it’s still there 50 years later,” Christian said.

Dairy Farms In California May Transmit H5N1 Virus Through Multiple Sources

 May 6, 2026

By Eurasia Review

The H5N1 strain of highly pathogenic avian influenza H5N1 has been detected in over 700 herds of dairy cows in California, the largest dairy-producing state in the U.S. A study published in the open-access journal PLOS Biology led by Seema S. Lakdawala at Emory University School of Medicine, U.S. and Jason Lombard at Colorado State University, U.S. suggests that avian influenza (H5N1) is transmitted through multiple, previously unknown sources and that some H5N1 positive cows do not show clinical signs of infection.

H5N1 may spread on dairy farms through direct contact with unpasteurized milk, such as via contaminated milking equipment. However, the full picture of how the virus can be spread on farms with infected cows is unclear. In order to better understand transmission routes of avian flu on dairy farms, researchers took air, farm wastewater, and milk samples on fourteen dairy farms testing positive for H5N1 across two different California regions between October 2024 and January 2025. They tested all samples for the presence of virus and performed genome sequencing on detected virus to identify any genetic variants and mutations.

The researchers detected airborne virus from the exhaled breath of infected cows and in the dairy parlor, identified the presence of virus in the wastewater, and found a high prevalence of cows who tested positive for H5N1 despite being asymptomatic.

The extensive environmental contamination of infected dairy farms suggests a higher risk of viral spread from cows to humans and other animals. However, future studies are needed to validate these results as longitudinal sampling of individual cows was limited to only fourteen animals. Sampling across a larger sample of farms over a longer time period is also needed to support the findings.

Dr. Lakdawala notes, “Our data confirm the presence of infectious H5N1 virus in the air and reclaimed farm wastewater sites. In addition, we observed high viral loads and H5 antibodies in the milk of cows, including those without clinical signs, suggesting that multiple modes of H5N1 transmission likely exist on farms. These results identify additional sources of viral exposure for cows, peridomestic wildlife, and humans, highlighting the need for multiple mitigation strategies to reduce the spread of H5N1 within a herd and to humans.”

The authors add, “Detection of infectious virus in the air and waste streams on farms was surprising but highlights that there is a considerable amount of infectious virus on farms and multiple sources of infection exist.”

“Targeted interventions in the dairy parlors to reduce the amount of aerosols in the air and inactivation of sick milk prior to disposal will provide additional barriers to infection of farm workers and likely other farm animals.”