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Covid infections in animals raise scientific concerns

This week’s decision by the Danish government to kill millions of minks due to coronavirus concerns and effectively wipe out major domestic industries is the science of animal vulnerabilities to pandemic viruses and what infectious diseases It may make sense for humans among animals that have spotlighted the simmering worries between those and protectionists.

The most annoying possibility is that the virus can mutate in animals and become more contagious or more dangerous to humans. In Denmark, the virus traveled from human to mink and back to humans, mutating in the process. Mink is the only animal known to have passed the coronavirus to humans, except for the first spillover event from an unknown species. Other animals, such as cats and dogs, have been infected by human exposure, but there are no known cases of infection by pet exposure.

The version of the virus that mutates in mink and spreads to humans is less contagious and does not cause more serious illness in humans. However, one of the variants found so far in 12 people was less responsive to antibodies in lab tests. Danish health officials were concerned that the effectiveness of the vaccine under development could be reduced in this variant and decided to take all possible steps to stop its spread. This included killing all minks in the country and effectively blocking the northern part of the country where the mutated virus was found. The UK bans travelers from Denmark who are not British citizens.

Scientists outside the World Health Organization and Denmark say they have not yet seen evidence that the mutant has any effect on the vaccine. However, they have not criticized Denmark’s decision to eliminate mink populations.

Mink is not the only animal that can be infected with the coronavirus. Dogs, cats, tigers, hamsters, monkeys, ferrets and genetically engineered mice are also infected.

Dogs and cats, including tigers, appear to be largely unaffected. Other animals used in laboratory experiments responded differently. However, farmed mink has died in large numbers in Europe and the United States. This is probably due to the congestion of these ranches, which could increase exposure.

However, public health experts are worried that potentially infectious species can become reservoirs that allow the virus to reappear and infect people at any time. The virus can also mutate in other animal species, as shown to mutate in mink. Most mutations are likely to be harmless, but SARS-CoV-2 can probably recombine with another coronavirus and become more dangerous. Conservation experts are also worried about the impact on already problematic animal species.

One approach to studying susceptibility is to examine the animal’s genome to see if it has a gene sequence that encodes a protein on the cell called the ACE2 receptor that allows the virus to latch. was. One research team studied the genomes of more than 400 animals. Another group conducted a similar study on primates, which are often infected with the human respiratory virus.

“One of the prerequisites for doing this study was that we thought that apes were at great risk because they are genetically closely related to humans,” said Amanda, an anthropologist and author at the University of Calgary. D. Melin said. Study of primates.

But she and her colleagues also wanted to consider “all other primates and their potential risks,” she added. In addition to investigating the genome, the team also computer-modeled the interaction of viral spike proteins with various ACE2 receptors.

The findings of both papers reinforce each other and reveal that Old World monkeys and all apes are at greatest risk. Both papers were published earlier this year as unpeer-reviewed studies.

Dr. Melin and her colleagues were talking to representatives of wildlife sanctuaries and zoos about the need for attention. Many of these facilities have tightened restrictions on interactions between people and primates.

Zarin Machanda of Tufts University, who is studying the behavior of chimpanzees in the Kibale Orangutan Project in Uganda, said the sanctuary’s security measures have been strengthened for the pandemic.

“We are always paying attention to respiratory viruses,” she said. Because such viruses are the leading cause of death in Kibaale orangutans. Even the common cold in humans can be fatal.

Orangutans suffer from the development of other coronaviruses. Normally, Kibaale humans are kept at least 20 feet away from chimpanzees. It has increased to over 30 feet. Local workers stay in the reserve rather than going back and forth to the community. The project also reduced field research time. All of these measures were directed by the Ugandan government.

Tony Goldberg, a veterinarian at the University of Wisconsin-Madison and head of the Kibaale Eco-Health Project, said he saw the devastation caused by respiratory illness in orangutans. The fatal outbreak in the protected area in 2013 was found to be the result of hitrinovirus C, the most common cause of colds around the world. Until then, it was not seen in orangutans.

“The last thing we need is that SARS-CoV-2 can move to an animal reservoir and reappear from there,” said Dr. Goldberg.

Other researchers are studying species from beluga whales to white-footed mice for signs of coronavirus. Kate Sawatsuki, animal surveillance coordinator for pet and other animal testing projects at Tufts University’s Cummings Veterinary School, said: “So far, we have tested 282 wildlife samples from 22 species, primarily New England rehab facilities, from bats, and we are pleased to report that none of us were positive.”

They also tested 538 domesticated pets, including those from homes with Covid-19 people, but showed no signs of active virus. However, according to Dr. Sawatsuki, the lab also performed a blood test for the antibody, showing exposure, and found the antibody, which is common in humans. The pet appeared to be infected, but did not get sick or get infected with the virus.

So far, Danish mink is the only known example of a virus that infects animals, mutates and infects humans. Emma Hodcroft of the University of Basel, Switzerland, tracked various mutated versions of the coronavirus that spread throughout Europe and confirmed scientific information published by the Danish health authorities. She said she took swift action and praised the government’s decision to eliminate mink. “I hesitated and waited before many countries acted.

However, she did not approve the way the information was disclosed. In particular, the government’s Wednesday press conference warned of a dire threat to potential human vaccines, but did not provide details of concerns. “Scientific communication is much clearer and may have reduced concerns around the world,” said Dr. Hodcroft.

Covid infections in animals raise scientific concerns

Source link Covid infections in animals raise scientific concerns

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