The strain of bird flu that has affected American farms for the last four years has led to the deaths of two individuals who contracted it from infected animals. However, it appears that the virus isn’t capable of spreading between humans. Essentially, it’s still very much a “bird” flu, designed to latch onto avian cells and not human respiratory systems, where it might typically cause coughing and sneezing that spreads the virus.
That said, there are conditions under which this could change. Experts warn that a single mutation could allow the bird flu to infect humans and potentially trigger a pandemic, which could be more lethal than COVID-19.
For such a scenario to unfold, the virus would likely need to find an intermediate host—an animal susceptible to both bird and human viruses. These intermediate hosts would have to be in close quarters, increasing the likelihood of a mutation that enables a cross-species leap. After that, this new strain would need to have the opportunity to spread among humans without being detected.
A recent investigation reveals that the right conditions are currently present. An outbreak of bird flu has been raging on a Utah mink farm for over two months. Mink possess lungs and airways that are, on a cellular level, quite similar to those of humans, and they have previously been known to catch and transmit various strains of the flu, including COVID-19.
Instead of trying to contain the outbreak to protect humans, state and federal authorities have largely remained silent, attempting to keep what’s happening under wraps. This lack of action has been described by flu experts as “irresponsible” and “puzzling,” with one expert even likening it to “playing with fire.”
Utah agriculture officials were aware as early as mid-August that birds were dying of bird flu at C&T Fenn Farms, located roughly an hour south of Salt Lake City, based on communications disclosed under public records laws.
Had poultry been infected, standard protocol would dictate that if a single chicken tested positive, the entire flock would need to be culled to safeguard other farms and public health. Farmers who lose their poultry are typically compensated for their losses.
However, there are no federal regulations governing how to handle sick mink. The state’s veterinarian, Amanda Price, sought assistance from the U.S. Department of Agriculture, which manages bird flu outbreaks in poultry and livestock.
The USDA indicated it does not regulate mink and lacks an approved vaccine for them. Though the Centers for Disease Control and Prevention reached out to Price’s health department colleagues, they did not communicate with her directly, nor did she initiate contact.
Throughout this situation, concerns about the potential for the outbreak to spill over into humans seem to have escaped the notice of Utah officials. Instead, they have focused on the interests of the fur business that relies on these animals, which has drawn criticism from various experts.
“It has been devastating,” Price said about the situation, expressing sympathy for the farm’s owner, whose life’s work is being compromised. “There’s a level of humanity here that should be acknowledged.”
Experts in flu transmission have argued that the government should have ordered the farm to cull its mink, as other countries have done in similar situations involving bird flu outbreaks. Yet, Utah officials did not seriously contemplate this course of action, as a representative from the fur industry warned Price that a culling would effectively destroy the business.
“There aren’t many paths forward other than waiting to see what happens,” Price noted, adding that USDA officials had not pressured her to cull the mink nor indicated that bird flu in those animals was any more concerning than infections in other species such as cows and ducks.
This response has surprised many flu specialists. “Most countries that have encountered H5N1 in fur farms have acted quickly to depopulate those animals,” said Tom Peacock, who studies avian influenza. “The hesitation to act immediately is alarming.”
Moreover, there’s been a lack of monitoring for symptoms among mink farm workers, which is something the CDC advises. Given that workers are often in close proximity to the mink, their exposure risk is quite high.
“The mink are tough creatures,” explained a nearby worker, showcasing scars from bites. “They can be really aggressive; it’s a bit scary.”
In Washington state, officials are currently trying to locate the contacts of a person who recently showed symptoms after being exposed to infected dairy cattle with bird flu. This proactive tracking is something that Utah health officials used to do, but these efforts ceased after complaints from the agriculture department about the inconvenience it caused farmers.
“Active monitoring was reportedly making it difficult for farms to cooperate,” lamented Pamela Gomez Pinedo, a respiratory disease epidemiologist in Utah’s health department. As a result, public health workers have struggled to obtain detailed information from agricultural officials.
The Department of Agriculture in Utah and the health department agreed not to actively monitor workers unless there’s evidence of human-to-human transmission. This policy persisted even as the outbreak lingered, raising alarms among health officials who questioned how to identify potential infections if no one is being tested.
Price argued that the lack of monitoring was intended to allow farmers to decide whether to contact health officials rather than impose it upon them. “If we start seeing active human cases, things might change pretty quickly,” she remarked.
Researchers have identified eye redness as a typical symptom in human cases of bird flu. This symptom appears in over 90% of reported cases, sometimes being the only observable sign.
Recently, a reporter managed to find two individuals who worked at the Utah mink farm, one of whom exhibited noticeably red eyes. Following this, the owner contacted the health department, who suggested there was no need for testing since the condition had resolved.
“They’re not going to do anything about it,” said Fenn, the farm owner. “Their stance was there’s no need unless other symptoms appear.”
Flu experts expressed shock over the lack of government action regarding testing the workers or managing the farm effectively. “It’s astonishing,” remarked Gail Hansen, a former public health veterinarian. “We don’t want ourselves to be the epicenter of another flu pandemic.”
Historically, many of the new viruses that have emerged in humans stem from animal sources, such as Ebola from bats and HIV from chimpanzees. The predominant theory surrounding COVID-19 traces its origins to a jump from bats to humans via an intermediate mammal, while previous flu pandemics resulted from bird flu viruses mutating to infect humans.
Experts have urged a “one health” approach, emphasizing that threats to animals should also be seen as threats to people. However, this approach is currently lacking in Utah, according to the findings of the ProPublica investigation.
Officials from both state and federal levels failed to act decisively. “There’s no leadership coordinating this ‘one health’ initiative,” noted Erin Sorrell, a researcher at Johns Hopkins University. “This void allows the virus to persist and adapt, increasing the chances it could infect another host, whether animal or human.”
This particular bird flu strain began causing problems for poultry in early 2022 and has since adapted to infect other species, including cows. Despite this development, federal guidelines do not consider cows a risk for infection on mink farms. These guidelines mainly suggest preventing wild birds from entering and avoiding feeding raw poultry to mink, ignoring the common practice of using beef parts for mink during summer months.
While cattle exposed to bird flu are not culled, they can still be slaughtered and sold for consumption, even though research has shown the presence of the virus in their tissues. Fenn acknowledged that mink are often fed raw livestock organs, including those from cows.
The genomic data from sick mink in Utah indicates they were infected with the same strain circulating in dairy cattle. However, there’s still uncertainty regarding whether contaminated beef caused the infections in the mink.
Mink’s respiratory systems may make them a more suitable host for the bird flu to adapt into a strain that could infect humans compared to other animals. A study conducted on dairy strains showed that a solitary mutation could enable the virus to shift from preferring avian receptors to those found in humans. Research on ferrets has illustrated that mutations allow the virus to target human-type receptors.
Experts are still unsure of how significant an evolutionary shift would be necessary for this strain of bird flu to spread among humans or if mink could indeed serve as the host for this change.
How this situation unfolds “really depends on the virus’s behavior,” remarked Meghan Davis, an epidemiologist at Johns Hopkins University. “We might get lucky and avoid a significant outcome, but then again, we might not.”
Additionally, there’s a danger of “reassortment,” where another flu virus could infect the same cell together with the bird flu virus, potentially exchanging segments of genetic material already optimized for human infection.
The outbreak occurred when seasonal flu activity was low, but by September, the flu season started unusually early. This timing heightens fears as an overlap of strains might provide the necessary conditions for a pandemic. Jennifer Nuzzo, director of the Pandemic Center at Brown University, warned that the most likely scenario for a pandemic would be a virus that reassorts with another virus, and “having this circulate amidst a human flu season is less than ideal.”
Interestingly, Utah officials showed more urgency regarding spillover threats in 2020, when COVID-19 outbreaks surged on mink farms in the same area. They had invited federal officials to study how the virus changed and spread during that time.
Traps were set around infected properties to catch mink capable of escaping, revealing those infected with COVID-19 that had likely come from the farms. Both wild and farmed mink were tested to help track how the virus propagated and mutated.
Unlike those proactive efforts, no similar measures are being taken now in response to bird flu in Utah.
A spokesperson for the USDA noted that its heightened involvement in 2020 was due to the pandemic potential of COVID-19, which presented significant risks to both humans and animals. They had initially provided genomic data from dead mink showing no concerning mutations, as reported by experts and the CDC.
However, experts now believe that the virus has likely continued mutating as it spread among mink. The key question remains whether these mutations could enhance its ability to infect humans.
“As long as the virus circulates among the mink, the probability of it jumping to humans increases,” stated Hansen.
Fenn mentioned that new samples were taken about two weeks ago, and Price confirmed she is still awaiting results.
These circumstances remain concerning. Experts stress that the conditions on that Utah farm could easily lead to a significant health threat if left unchecked. “Honestly, I’d want every precaution possible if I were there,” Peacock commented. “Or better yet, I’d rather not be there at all.”
