The strain of bird flu that’s ripped through American barns for the last four years has killed two people who caught it from sick animals, but as far as anyone can tell, humans can’t spread it:
The virus has remained a true “bird” flu, tailored to attach to avian cells, not invade human throats and noses, where coughing and sneezing reliably spew droplets.
Under the right conditions, however, that could change. A single mutation could give the bird flu a foothold in people and spark a pandemic that experts fear could be deadlier than COVID-19.
For that to happen, this bird flu would likely need to find an intermediate host — an animal vulnerable to viruses that infect both birds and humans. These animals would be crowded together, each infection raising the odds that a new strain could arise through mutation. Then, for that strain to jump across species, it would have to have access to humans and time to spread among them undetected.
That perfect petri dish exists right now, a ProPublica investigation found. For over two months, an outbreak of bird flu has raged uncontrolled on a Utah farm that raises thousands of mink for fur. Mink have lungs and airways that on a cellular level are remarkably similar to those of people; they have caught and spread other flus and infected some humans with COVID-19.
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Utah agriculture officials learned in mid-August that mink were dying of bird flu on C&T Fenn Farms, about an hour’s drive south from Salt Lake City, according to communications released under the state’s public records law.
Had poultry been infected, the playbook would have been clear: The strain is so virulent that if a single chicken tests positive, the U.S. government requires farmers to kill the whole flock to protect other farms as well as public health. Poultry farmers are reimbursed for the loss.
But there are no federal rules for how to deal with sick mink.
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A telltale sign of bird flu infection in humans is eye redness. It is present in over 90% of cases and is often the sole symptom a person displays.
Last Saturday, a ProPublica reporter tracked down two people who worked at the Utah mink farm. One had a visibly red eye.