Bird Flu Has Raged Unchecked for Two Months on a Utah Mink Farm. Experts Call It 'Playing With Fire.'

For more than two months, a strain of bird flu has been killing mink by the thousands on a commercial fur farm in Utah — and neither state nor federal officials have ordered the animals culled, imposed a formal quarantine, or systematically tested the workers who handle them every day. Infectious disease experts, reviewing the response, have called it 'irresponsible,' 'puzzling,' and 'playing with fire.'

The outbreak at C&T Fenn Farms, about an hour south of Salt Lake City, is the first confirmed case of highly pathogenic avian influenza H5N1 in captive mink in the Americas, according to genomic surveillance data published on Virological.org by researchers at the National Institutes of Health, Imperial College London, and the CNRS in Paris. Samples collected on August 7, 2026, confirmed the virus belongs to genotype B3.13 — the same strain that has been circulating in U.S. dairy cattle since 2024. By late September, the outbreak was still ongoing and approximately 80 percent of the herd had died, according to ProPublica, which obtained state communications through Utah's public records law.

Why mink? The answer lies in biology. Mink express a high proportion of the same α2,6-linked sialic acid receptors found in the human upper respiratory tract — the molecular doorway that influenza viruses use to enter cells — making them susceptible to both avian and human flu strains, according to the Virological.org genomic report. That dual susceptibility means a densely housed mink population is precisely the kind of environment where an avian virus could swap genetic material with a human flu strain, potentially producing a new variant capable of spreading between people. Researchers call this process reassortment; it is one of the mechanisms that produced past pandemic influenza strains.

Every other country that I'm aware of that has had H5N1 in fur farms, depopulation has happened pretty quickly. The fact that the first instinct wasn't just to depopulate and figure stuff out later is very concerning to me.— Tom Peacock, avian influenza researcher, Pirbright Institute

The genomic analysis adds a specific molecular reason for concern. All ten Utah mink virus sequences carried a PB1-K388R substitution — a mutation previously observed in the 2022 H5N1 mink outbreak in Galicia, Spain, but rarely seen in avian hosts and absent from cattle isolates, according to the NIH-led team on Virological.org. The virus also retained the PB2-M631L mutation already present in the cattle-adapted B3.13 genotype, which increases replication in mammals. The combination has not been seen before in the Americas.

When Spain identified H5N1 on a mink farm in 2022, authorities announced depopulation of the entire farm within two weeks. Finland followed a similar playbook across 27 fur farms in 2023. In Utah, the response has been different. State veterinarian Amanda Price sought guidance from the U.S. Department of Agriculture, which told her it did not regulate mink and had no approved vaccine for the species, according to ProPublica. CDC officials spoke with Utah health department staff but never directly with Price, and she never reached out to them. The result was a regulatory vacuum with no federal authority claiming ownership of the problem.

There's just not a lot of options out there other than kind of sitting and waiting and seeing what happens.— Amanda Price, Utah state veterinarian

Filling that vacuum was the fur industry. A fur trade representative warned Price that culling the mink at C&T Fenn Farms would destroy the business and ultimately the industry — mink farms spend decades developing unique genetic lineages, making a single herd difficult to replace. Price told ProPublica she felt the weight of that: 'It has been devastating. This is his life's work that he's seeing be destroyed.' Farm owner Chad Fenn did not dispute the outbreak but told ProPublica that a worker observed with a red eye — a symptom the CDC says warrants testing for bird flu — simply had dust in his eye, and that the state health department had not recommended testing.

The contrast with how poultry outbreaks are handled is stark. Under existing federal rules, a single positive chicken triggers mandatory culling of the entire flock, with farmers reimbursed for their losses. No equivalent rule exists for mink. Utah officials placed only a non-binding 'verbal hold' on the movement of live mink, carcasses, and manure, according to CRV Science, which reviewed the public records. No follow-up viral samples were collected after the initial August submission, meaning there is no genomic window into how the virus may have evolved over the two months it has been replicating inside thousands of mammals.

Worker monitoring fell through a separate gap. CDC guidance calls for active symptom surveillance of people exposed to infected animals. Utah health officials had previously done such monitoring, but stopped after the agriculture department reported that farmers found it intrusive. 'Us doing active monitoring was making it so that farms didn't want to work with them,' respiratory disease epidemiologist Pamela Gomez Pinedo told ProPublica. ProPublica reporters independently located two farm workers, one of whom had a red eye.

No animal or human will be protected from the toll of this virus through secrecy. The risk is greatest among people who have exposure to sick animals. If that is not you, I think you can take this off your worry list, [but] it does not abdicate the government of its responsibility to try to prevent a pandemic.— Jennifer Nuzzo, epidemiology professor and director, Pandemic Center, Brown University School of Public Health

Nuzzo said she sees no current signals that the virus is spreading to humans, and she was careful to note that the probability of a pandemic emerging from this specific outbreak 'could be zero.' But she framed the danger in terms of what is not being done: farm workers are not being protected with vaccines that other countries are using, and the expert briefings that federal officials once held with outside researchers — sessions that allowed scientists to scrutinize government decisions — have stopped since the start of the Trump administration's second term.

The scenario I'm worried about is this one: workers who are exposed to these animals will get sick, and some of them might die, and that is awful because we potentially could prevent that through thinking about protecting farm workers with a vaccine, like other countries are using.— Jennifer Nuzzo, epidemiology professor and director, Pandemic Center, Brown University School of Public Health

The Utah outbreak is not the first time mink in the United States have been caught in a zoonotic crisis. During the COVID-19 pandemic, nearly 10,000 mink in Utah died from the coronavirus and quarantines were implemented at nine farms, according to The Guardian, citing the journal Emerging Infectious Diseases. In that case, the virus was transmitted to the animals from infected workers — the reverse of the direction experts now worry about.

The broader federal surveillance context has also narrowed. Shortly after President Trump took office for his second term, his administration fired federal employees who had been responding to a bird flu outbreak among dairy cows, according to The Guardian. Nuzzo said the regular expert briefings that once allowed outside researchers to question federal decision-making have ended. 'A lot is lost when that doesn't happen,' she said. 'It might mean that things are going on that people don't see or know about. It might also be that actions don't get the scrutiny they deserve.'

As of the latest available reports, no human cases linked to C&T Fenn Farms have been reported, and no major new containment measures have been announced. The USDA did not respond to requests for comment from The Guardian. Price and the Utah Department of Agriculture and Food also did not respond.

Why it matters — An uncontained H5N1 outbreak in mink — mammals whose respiratory cells closely resemble human ones — represents one of the conditions scientists have long identified as a potential stepping stone to a human pandemic, and the regulatory gaps exposed in Utah have no clear fix in place.

Sources differ on Red eye in farm worker: Worker had a red eye warranting CDC-recommended bird flu testing (propublica.org) vs Worker had dust in his eye; state health department did not recommend testing (propublica.org (quoting Chad Fenn))

Reported by theguardian.com, propublica.org, virological.org, crvscience.com, yahoo.com, respiratory-therapy.com