As a deadly form of avian influenza continues ravaging bird populations around much of the world, scientists are tracking infections among other animals — including various types of mammals more closely related to humans.
Throughout the last year, Canadian and U.S. officials detected highly pathogenic H5N1 avian flu in a range of species, from bears to foxes. In January, France’s national reference laboratory announced that a cat suffered severe neurological symptoms from an infection in late 2022, with the virus showing genetic characteristics of adaptation to mammals.
Most concerning, multiple researchers said, was a large, recent outbreak on a Spanish mink farm. Last October, farm workers began noticing a spike in deaths among the animals, with sick minks experiencing an array of dire symptoms like loss of appetite, excessive saliva, bloody snouts, tremors, and a lack of muscle control.
The culprit wound up being H5N1, marking the first known instance of this kind of avian influenza infection among farmed minks in Europe, notes a study published in Eurosurveillance this month.
“Our findings also indicate that an onward transmission of the virus to other minks may have taken place in the affected farm,” the researchers wrote. Eventually, the entire population of minks was either killed or culled — more than 50,000 animals in total.
That’s a major shift, after only sporadic cases among humans and other mammals over the last decade, according to Michelle Wille, a researcher at the University of Sydney who focuses on the dynamics of wild bird viruses.
“This outbreak signals the very real potential for the emergence of mammal-to-mammal transmission,” she said in email correspondence with CBC News. It’s only one farm, and notably, none of the workers — who all wore face shields, masks, and disposable overalls — got infected.
But the concern now, said Toronto-based infectious disease specialist Dr. Isaac Bogoch, is if this virus mutates in a way that allows it to become increasingly transmissible between mammals, including humans, “it could have deadly consequences.” “This is an infection that has epidemic and pandemic potential,” he said. “I don’t know if people recognize how big a deal this is.” (SOURCE)
