Researchers detect first potential case of COVID-19 transmission between deer and humans – Dal News


A team of researchers from Dalhousie and other Canadian organizations have discovered what may be the first link between a case of COVID-19 in deer and humans, suggesting in a new paper that the virus can be transmitted from wildlife to the man.

Finlay Maguire, a data scientist and assistant professor in the faculty of computer science and the department of community health and epidemiology at Dal, participated in the national research project that monitors the spread of SARS-CoV-2 in animals.

The article, which has not yet been peer-reviewed and is published on the online preprint server bioRxiv, explains that although there is evidence of the spread of the COVID-19 virus from humans to white-tailed deer, there has been no clear discovery yet. of such transmission from deer to humans.

“With respect to this specific lineage, it is not of great concern at this time. We have not detected any additional related human cases and experimental work suggests that current mRNA vaccines would be effective in protecting against this lineage” , says Dr. Maguire.

“However, the overall evolutionary scenario this represents is concerning: SARS-CoV-2 viruses undergo significant evolution within animal populations and then spread to humans.”

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The multidisciplinary team, made up of researchers from several universities, federal and provincial government agencies, identified a novel, highly divergent lineage of SARS-CoV-2 that has 76 mutations, including 37 previously associated with animal hosts. Of these, 23 had not been previously reported in deer.

The analysis also revealed one epidemiologically linked human case in the same region of Ontario during the same sampling period.

“Together, our findings represent the first evidence for a highly divergent lineage of SARS-CoV-2 in white-tailed deer and transmission from deer to humans,” the authors state.

The finding is significant since scientists are closely monitoring wild animal populations to determine if they could generate new variants or harbor the current SARS-CoV-2 virus.

The team analyzed samples from hundreds of deer killed by hunters in Ontario in 2021. They compared the mutation pattern of deer virus and a person who had contact with deer in the area, finding strong similarities. They also used these models to try to recreate the “family tree” of these viruses, which tells them that the virus they found in a human likely descended recently from a deer SARS-CoV-2 virus. .

By sequencing this virus, they also found signs suggesting that it has been spreading and evolving in deer for one to two years. And, this has a very different genetic profile from the omicron and delta variants.

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Contact with humans

Scientists have long known that SARS-CoV-2 can infect a wide range of mammals and likely originated in animal populations, with research indicating that a market in Wuhan, China is the source of the outbreak. coronavirus pandemic. New studies have recently revealed that the virus was likely present in live animals sold at a seafood market in late 2019 and infected people who worked or shopped there.

SARS-CoV-2 has been identified in wild white-tailed deer across North America. This is potentially a problem because there are lots of deer, they move around a lot and they have a lot of contact with humans and other animals, Dr Maguire says.

“This means that if SARS-CoV-2 is able to spread stably in deer and retransmit to humans, it could represent a difficult source for new variants to control.”

“Our findings likely represent the last leap of the virus between animals and humans: from animals to humans during the original Wuhan event(s), back to animals such as mink and deer around 2020, then this last transmission from deer to the man. “

Dr Maguire says the findings point to the need for further surveillance and study of the viruses in wild animal populations, saying “the limited amount of work on SARS-CoV-2 in animals means that much information is lacking on the specifics of how, when and why these transitions occur or their impact on human health.”

The Public Health Agency of Canada advises “those who hunt, trap, or work closely with or handle wild animals to take precautions to prevent the potential spread of the virus.” It says on its website that there has been a suspected case of deer-to-human transmission, adding that it appears to be an isolated case and that animal-to-human transmission is likely very rare.

The research was a large collaboration, including Bradley Pickering, Oliver Lung and Peter Kruczkiewicz from the Canadian Food Inspection Agency, Samira Mubareka from the Sunnybrook Research Institute, Marceline Côté from the University of Ottawa, Jennifer Guthrie from Public Health Ontario/Western and Tore Buchanan, Larissa Nituch and Jeff Bowman at the Ontario Ministry of Northern Development, Mines, Natural Resources and Forestry.


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