Denmark to cull all farmed mink to stop coronavirus outbreaks

A photo of a mink in a farm in Hjoerring, in North Jutland, Denmark, on October 8, 2020
(Image credit: MADS CLAUS RASMUSSEN/Ritzau Scanpix/AFP via Getty Images)

Denmark, the world's largest producer of mink, will cull all farmed mink in the country to prevent the spread of coronavirus infection, both between the animals and to their human handlers, Danish authorities announced Wednesday (Nov. 4).

There are currently more than 15 million mink being raised at more than 1,000 farms in Denmark, The New York Times reported; so far, several hundred farms have reported SARS-CoV-2 infections among their mink, including more than 200 farms in Jutland, the mainland part of Denmark, according to the Danish Broadcasting Corporation

While the virus spread among these mink, it picked up new genetic mutations. That's not unexpected as viruses mutate continually, and new variants often emerge over time, especially when that pathogen hops between different species. New variants of the coronavirus may or may not change how it infects cells or how easily it spreads. 

However, Danish authorities expressed concern that, should the mutated virus spread among humans, the COVID-19 vaccines currently in development may not work as well against the new variant. The first cases of minks transmitting the coronavirus to humans emerged from the Netherlands over the summer, according to The Washington Post, and already, 12 people in the Jutland region have caught the newfound virus variant from mink, Danish Prime Minister Mette Frederiksen said at a press conference, according to the Times. 

Warnings about the mutated virus came from the State Serum Institute, the Danish government's public health and infectious disease arm.

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"We have a great responsibility towards our own population, but with the mutation that has now been found, we have an even greater responsibility for the rest of the world as well," Frederiksen said at the press conference, according to BBC News.

Research by the State Serum Institute suggests that, in infected people, the mutated virus shows "reduced susceptibility to antibodies," she said, but no details have been shared about how that conclusion was reached. Until those details are published, statements about how the mutated virus interacts with the human immune system cannot be properly evaluated, Stanley Perlman, a microbiologist at the University of Iowa, told the Times. 

Denmark has informed the World Health Organization of the mutation and infections. 

"We are in touch with them to find more about this event," the WHO told the Times in an email. Again, until scientists study the mutations more closely, they won't know whether the new variant could interfere with the effectiveness of COVID-19 vaccines. Right now, there isn't enough information to determine whether or not the variant presents a significant problem. 

"Someone would have to release the [genetic] sequences soon, and the evolutionary biologists will be all over it," Dr. Jonathan Epstein, vice president for science and outreach at the EcoHealth Alliance, a conservation organization, told the Times.

Farmed minks began contracting the novel coronavirus in the Netherlands as early as April, and in June several farm workers reportedly caught the virus from the sick animals, The Washington Post reported. Some infected minks show no overt symptoms, while others can develop nasal discharge, difficulty breathing and even pneumonia, Science Magazine reported. By mid-June, 12 of about 130 Dutch mink farms had cited cases of the virus, but Denmark had not yet reported any outbreaks. 

At this point, mink SARS-CoV-2 infections have been reported in several additional countries, including Spain, Sweden and the United States, where thousands of mink were recently culled in Utah. Worldwide, millions of farmed mink have already been culled due to these outbreaks, BBC News reported.

Originally published on Live Science.

Nicoletta Lanese
Channel Editor, Health

Nicoletta Lanese is the health channel editor at Live Science and was previously a news editor and staff writer at the site. She holds a graduate certificate in science communication from UC Santa Cruz and degrees in neuroscience and dance from the University of Florida. Her work has appeared in The Scientist, Science News, the Mercury News, Mongabay and Stanford Medicine Magazine, among other outlets. Based in NYC, she also remains heavily involved in dance and performs in local choreographers' work.