It is not yet clear to scientists why mink disperse Covid-19 so fast / Article / LSM.lv

No infection with the new coronavirus has been detected in mink farms in Latvia. The Food and Veterinary Office (FVS) is stepping up its monitoring of fur farms, which are required to comply with strict biosecurity measures. Why mink are suffering from Covid-19 is not yet clear to scientists.

In Denmark, the world’s largest producer of mink fur, farms are empty. 15 million fur animals were eliminated in a short time. In the mink population, the virus also mutated, and humans became infected with the new strain. Mink disease has also been confirmed in France and Poland. This week, mink also started dying on a fur farm in Lithuania. The animals were infected from a sick farm worker.

“It’s hard to say if the virus has mutated. Full sequencing of the full genome must be performed, ”says Professor Arūns Stankevičs of the Lithuanian University of Health Sciences. In Lithuania, the infection has not reached a level where infected mink could infect humans. Measures and restrictions are being taken and sick animals are being destroyed.

There are nine mink farms in Latvia. At the beginning of the summer, they contained about half a million mink. In the autumn, the animals began to be euthanized to obtain skin. At present, the work has been completed in four warehouses. In two – all mink have been removed. Five farms with breeding animals will remain for the winter.

“This disease has not been detected in mink in Latvia. Therefore, mink can not transmit this disease. If a mink were to get sick in Latvia, then it could happen through infected people, common people who would come into contact with the mink, ”says Kristīne Lamberga, Director of the Veterinary Surveillance Department of the Food and Veterinary Service.

The FVS, together with the BIOR Scientific Institute, conducts wastewater tests to determine whether mink farms have Covid-19 feet.

‘The first results from the farms surveyed do not show any indication that the mink have become infected there. We know from the experience of other countries that on farms where mink have been diagnosed with the disease, there is an increased mortality of these animals. Even in the framework of such passive monitoring, we have no indication from the nurseries that such a problem would exist, ”points out Lamberg.

Researchers are looking for answers to the question – why is there an outbreak in the mink population? According to scientists, it is not really known how many animal species have received SARS viruses from bats. Pangolin, from which the virus has spread to humans and then to mink, is commonly mentioned as one of the intermediate species.

“Scientists have found that the virus mutates much faster in the bat population than in humans. Mink also seems to have a factor that causes this virus to mutate, and there is a fairly high risk that the virus will transform and cause a second wave with a changed virus structure. But one of the main factors that determines all this is the ACE2 receptor, which is widely distributed among mammals, ”explains Professor Kaspars Kovaļenko, Dean of the Faculty of Veterinary Medicine of the Latvia University of Agriculture (LLU).

The ACE2 receptor in the body is responsible for lowering blood pressure. It is located on the lung epithelium, blood vessels, liver, intestines, kidneys. The disease begins when the virus enters the lungs through the upper respiratory tract.

“It finds this ACE2 receptor, which attaches to and enters the cell. Now, looking at the structure of the ACE2 receptor between different animals, we see that the receptor between humans and mink is similar. It is also similar to cats, whales, dolphins, if you look at all mammals in general, ”says Kovalenko.

It is not yet clear why other animals are not infected in this case. “When compared to other animals, such as pigs, which have been shown to be able to replicate the virus, (it is not clear) why reproduction.

This means that there is another mechanism that we do not fully know about, ”admits the professor.

Probably one of the factors could be the high density of the animals. Mink farms are kept in cages, outdoors. Animals can easily stick to each other. In addition, in Europe, some mink breeds are more susceptible, others less susceptible to disease. More resilient are those that are related to wild mink.

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