The World Health Organization is investigating mink farming around the world over concerns that the animals might pass on dangerous new Covid-19 strains to humans — some of which threaten the effectiveness of vaccines currently in development — a day after Denmark ordered the cull of its entire 17 million-strong herd after failing to contain mink-related outbreaks that have already infected at least 214 people in the country since June.
Denmark ordered the culling of its entire mink herd after failing to contain coronavirus outbreaks … [+]
Maria van Kerkhove, the WHO’s technical Covid-19 lead, said the organization was looking at the biosecurity of mink farms around the world in a bid to “prevent spillover events,” Reuters report, a day after Denmark ordered the culling of its entire herd.
Spillover events, which van Kerkhove described as “a concern,” are events where pathogens jump the species barrier into a new host such as from a mink into a human.
Spillovers can be exceptionally dangerous to the new species — with Ebola, HIV, Zika, and the virus behind Covid-19 all the products of such events — and mink seem to be exceptionally vulnerable to Covid-19, a situation worsened in farms where they are kept in large numbers in close proximity.
One mutated coronavirus strain in particular worried the Danish authorities so much that they ordered the culling of the country’s entire herd of mink, even though it has only been found on five farms and in 12 people.
Speaking Thursday, Danish prime minister Mette Frederiksen described the threat from the mutated virus as “very, very serious” with potentially “devastating consequences worldwide.”
Minks appear to be particularly hard hit by the coronavirus, with outbreaks tearing through herds around the world which, in some cases, make the move back into human populations. Authorities in Denmark are worried about a particular strain of coronavirus moving back into humans from mink that appears to make it less sensitive to antibodies. This could render many of the vaccines currently in development less effective.
What We Don’t Know
There’s not much known at the moment about the particular strain of mutated coronavirus the Danish are so worried about, or about precisely why it represents such a threat. It is likely much more will be learned about the various viral strains and their prevalence when the animals are culled, something Denmark’s national police chief said “should happen as soon as possible.”
What To Watch Out For
Outbreaks of Covid-19 have already killed the Dutch mink industry, which was one of the largest in the world, by forcing forward existing plans to end the industry in 2024. It is unclear how other major producers, China and Poland, have been affected, or whether the WHO’s investigation and Denmark’s wholesale culling will prompt them to act in similar fashion.The response of other countries will also bear watching. The U.K. moved swiftly to remove Denmark from its coronavirus travel corridor list in direct response to the mink-related outbreaks.
Coronavirus is killing the Dutch mink industry (National Geographic)
Spillover: animal infections and the next human pandemic. David Quammen.
The Coming Plague: newly emerging diseases in a world out of balance. Laurie Garrett.