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A bird flu outbreak on a Spanish mink farm has scientists alarmed. An expert urges vigilance.
Avian flu is affecting more and more wild bird species worldwide. The virus now also occurs in summer and no longer only in winter and has already infected various mammal species, sometimes with fatal consequences for seals, dolphins, foxes and cats. Until now, the virus has been passed on through direct contact with an infected bird.
Now it is most likely jumping from one mink to another on a farm in Spain, says Ursula Höfle from the National Research Institute for Wildlife at the University of Castile-La Mancha.
SRF News: How did the virus get into the Spanish mink farm?
Ursula Höfle: It has not yet been 100% proven, but it was probably carried to the farm by black-headed gulls. These are open at the side for ventilation. The mink are fed on cages within easy reach of birds. We don’t know exactly yet, because individual sequences from mink virus and gull virus are not yet available for comparison.
This one mutation does not mean that it can be transmitted to every mammal. But it shows that the virus can acquire such mutations.
A mutation of the pathogen was detected in the mink, which favors the replication of the virus in mammals. How worrying is that?
This is very worrying for the mink. The mutation is very specific and may actually have ensured the spread from mink to mink. But this outbreak has stopped. And this one mutation does not mean that it can be transmitted to every mammal. But it shows that the virus can acquire such mutations.
Although there is no immediate danger to humans, the all-clear signal cannot be given under any circumstances.
The WHO has so far assessed the risk to the population as low. How justified is the fear of human-to-human transmission?
One does not already stand one step from a new pandemic. However, the H5N1 influenza virus has long been a good candidate because it is obviously very flexible. With the currently very high number of infected animals, there are constantly new infections and opportunities. The constant new infections in new species clearly show that the virus is currently changing very quickly. Although there is no immediate danger to humans, the all-clear signal cannot be given under any circumstances.
We are currently facing a panzootia, i.e. an animal disease that is spreading worldwide.
How dangerous is the virus for wildlife?
We are currently facing a panzootia, i.e. an animal disease that is spreading worldwide. And this especially in the colonies of breeding birds. In comparison, the cases of dying mammals are still sporadic. The mink farm is a special case, and the case of 600 dead sea lions sounds grim.
Legend:
Symbolic picture: dead eider duck on the North Sea beach, February 2022
Keystone/Axel Heimken
But at the same time, 8000 cranes are dying on one corner and 2000 pelicans, sguas or sandwich terns on another. Some of these are endangered species. Many experts expect major effects. It cannot be ruled out that individual species will disappear. It is practically impossible to contain the virus in wild animals across the board.
The conversation was led by Matthias Kündig.