What a bird flu outbreak in mink could mean for humans

Globally, the H5N1 variant that has spread in birds has resulted in fewer than 10 known cases in humans since December 2021, and there have been no documented instances of human-to-human transmission, according to the CDC

“The H5 virus is not well adapted to humans,” said Dr. Jim Lowe, a veterinarian at the University of Illinois College of Veterinary Medicine at Urbana-Champaign.

The fact that the virus emerged in a mink farm is not particularly surprising, he said, and is not necessarily alarming. “This is not, in my mind, a particularly worrisome situation for human health,” Dr Lowe said. “Obviously it’s not very good for the mink.”

But a mink-adapted version of the virus could pose a greater potential risk to humans. “It’s more likely that such a virus spreads more easily and efficiently among humans,” Dr Kuiken said.

Eleven farm workers had contact with the mink; all tested negative for the virus, Dr. Monne and colleagues reported. This fact is “reassuring”, said Dr Monne. “But clearly what is worrying is that this virus is spreading everywhere.” This means there will be more opportunities for the virus to infect, and potentially spread, in mink and other mammals.

The permeability of mink farms also means that a virus that begins to spread among mink could exit the farm. Mink sometimes escape from farms and dogs and cats in mink farms with coronavirus outbreaks have also been infected with the virus, scientists have found.

These animals could potentially act as intermediate hosts, transmitting a mink-mutated version of the virus to humans or wild animals. In a recent study, Dr. Barton Behravesh and his colleagues used GPS collars to track the movements of free-ranging cats living in or around several Utah mink farms that had experienced coronavirus outbreaks. The cats roamed widely, the researchers found.