Researchers say there is an urgent need to find out if animals are likely to be infected with the new coronavirus and transmit it to humans. Shortly after the new coronavirus began to spread around the world, there were reports of animal infections – pet cats in Hong Kong, tigers at New York City Zoo and otters on Dutch farms. Now, researchers are eagerly exploring which species will be infected with the new coronavirus and whether they will transmit the virus to humans.
So far, only two animals have reported transmission of the new coronavirus SARS-CoV-2 to humans – both otters. The researchers say the current likelihood of contracting a new coronavirus from infected animals is negligible compared to the probability of infection in humans.
However, as the number of human infections declines and population mobility restrictions ease, infected animals may trigger a new outbreak. Researchers are calling for extensive sampling of pets, livestock and wildlife to improve understanding of the potential risks.
Joanne Santini, a microbiologist at University College London, said the new coronavirus may have spread among animals that we don’t know yet, and “our data is not enough.” “
Several scientists worry that the new coronavirus will eventually spread back and forth between animals and humans. Arjan Stegeman, a veterinary epidemiologist at the University of Utrecht in the Netherlands, said it would undermine the epidemic and “we need to take immediate steps to prevent that from happening.” “
Animals at risk
There are about ten species of animals known to be susceptible to the new coronavirus. Several species, including pet cats and dogs, captive tiger lions and farm-bred otters, have almost all been infected with the virus from humans. This may mean that close relatives of canines, cats, and ferrets, including otters, weasels, moles, moles and wolves, are also susceptible, but so far no cases have been detected, said J.rGen, a veterinary virologist at Kansas State University.
Laboratories deliberately infected hamsters, rabbits and common macaques with the new coronavirus in experiments, and the results showed that they were also susceptible to the virus. Experiments on pigs, ducks and chickens have shown that they are not susceptible, but there is no research on other livestock, such as cattle and sheep. “If SARS-CoV-2 can spread among wild animals or other species that are in close contact with livestock, this increases the likelihood of interspecies transmission. Linda Saif, a virologist at Ohio State University, said.
Richt said more research should be done to assess the susceptibility of different species and whether they can infect other animals. In the laboratory, cats, ferrets, hamsters and chrysanthemum bats are able to transmit the new coronavirus to similar species, and the virus spreads between otters living not far from home on Dutch farms.
But the fact that an animal can infect a similar species doesn’t necessarily mean it can infect people, Saif says. To assess this risk, researchers need to learn more about how small amounts of the virus a person needs to be exposed to to become infected, she said.
Martin Beer, a virologist at the Federal Institute for Animal Health, said animals that emit large amounts of the virus and are in close contact with humans should be closely monitored.
Infections in Dutch otter farms have shown that some animals can infect humans. At least 24 otters were infected with SARS-CoV-2 at four farms in the Dutch province of North Brabant, some of whom suffered from pneumonia and were dying.
Stegeman and his colleagues studied the genomes of otters and humans on two of the farms and found that it was possible that some workers had transmitted the new coronavirus to the otter, which then spread between the otters. The findings were published May 18 in bioRxiv.
Stegeman said further genome analysis, which has not yet been published, suggested that a worker on one of the farms may have been infected with a otter. He said the worker appeared to have been infected after being exposed to otters at work, so it may have been that the otters were infected with people, not people. The infected person’s viral genome is also closer to the virus genome of the otter than to the genome of other infected people, including those living near farms.
Saif hasn’t seen the genome data yet, but she thinks the direction of the virus’s spread is hard to prove. Finding viruses close to each other, along with other circumstantial evidence, such as the timeline of virus exposure and onset, may help, but “it’s very difficult to directly prove that the virus from animal to human,” she said.
Still, Soren Alexandersen, director of the Geelong Centre for New Infectious Diseases in Geelong, Australia, said that could not be ruled out. He said the new coronavirus could spread quietly on other mink farms in Europe, North America and Asia.
It is not uncommon for pathogens to spread between different species, which makes it more difficult to control transmission. SARS-CoV-2 is most likely to originate in bats, but researchers don’t know if other animals have passed through it before it is transmitted to humans. The 2009 H1N1 influenza virus originated in pigs and spread to humans, then spread around the world, and finally back to pigs. The virus continues to spread among pigs and binds to other influenza viruses to form new variants that then spread to humans, Stegeman said.
Some scientists also worry that SARS-CoV-2 will spread back and forth between cats and humans, as cats often move between human families. Although cats can infect other cats, there have been no reports of cat infections.
Asisa Volz, a veterinary virologist at the School of Veterinary Medicine in Hanover, Germany, plans to investigate whether the cat has spread the new coronavirus in a Bavarian nursing home, where some people isolated from infected people have been infected. A cat was found to have traces of the new coronavirus RNA, which means the cat may have been able to excrete the virus while moving in the hospital. Volz and Beer will test the nursing home for new coronavirus antibodies and comb the timeline of the incident to see if the cat is a source of infection.
Stegeman also plans to test cats in the Netherlands for those who live with COVID-19. He says it will be harder to control the spread of the virus if cats are found to be able to transmit the new coronavirus to humans.
“It is no small matter that the pandemic virus forms a chain of transmission in animal populations and this possibility should always be taken into account. Beer said.