Contact with infected wildlife can likely spread COVID-19 to humans, scientists report

CANADA—In January, the Ministry of Northern Development, Mines, Natural Resources and Forestry (MNR) reported that the virus that causes COVID-19 (SARS-CoV-2) had been found in five white-tailed deer in London, Ontario. More recently, a similar strand was found in a human who had contact with the deer.

In a scientific paper published in late February (that has not yet been peer reviewed), researchers say that at least one case of COVID-19 in humans can be traced to a strain of the virus found in hunted deer. One of the authors of the report, Finlay Maguire (an assistant professor at Dalhousie University in Halifax, Nova Scotia) told The Expositor last week, “the results of sampling suggests transmission from deer into humans can take place. This is first time there has been evidence of this type of thing happening.”

Mr. Maguire said a large collaborative of academic researchers in Ontario, along with the federal protection agency, wrote the paper. “We know that deer can get COVID, and we knew that there could be spillover from humans into nearby wildlife.”

“But now, through the sampling of hundreds of white tail deer hunted last fall in southwestern Ontario, and a similar strand found in a human who had contact with the deer, that humans could conceivably get the virus from deer,” said Mr. Maguire.

“All of this suggests that transmission of COVID from deer into humans could presumably take place,” said Mr. Maguire.  He explained that researchers collected about 300 samples in November and December (last year) of white-tailed deer in Canada and found that 17 of the deer in southwestern Ontario had tested positive for SARS-CoV-2. Through further research, they also found a person who was infected with a genetically similar strain of SARS-CoV-2. The person lives in the same area as the 17 deer in southwestern Ontario and had close contact with the deer population prior to testing positive.

Scientists stress that the study only states that this is possible and in no way does it confirm deer infected the human.

Roderick Gagne, a wildlife disease ecologist at the University of Pennsylvania School of Veterinary Medicine was quoted by the New York Times as saying “we don’t have enough information yet to confirm that transmission back to humans.”

Mr. Maguire told The Expositor that the researchers had sequenced the genomes from five of the virus samples and, according to the study, they found “a new and highly divergent lineage of SARS-CoV-2. He also said the study found the lineage has a close genetic link to a strain that was in the samples taken from humans and mink in Michigan two years ago.

Arinjay Banerjee, a virologist at the University of Saskatchewan told the New York Times, “the more hosts you have, the more opportunities the virus has to evolve.”

Canada’s public health agency has indicated that there is no evidence that the virus had spread to humans and said it was likely an isolated case. “Until we know more, people who hunt, trap or work closely with or handle wildlife should take precautions to prevent the potential spread of the virus.”

“The good news is that only one case that this was found,” said Mr. Maguire. “we have a lot of questions to ask and need corresponding answers concerning these results.”

The Ontario MNR confirmed the five cases of deer found with COVID are the first cases reported in free-ranging wildlife in Ontario. Cases in wildlife have been detected in deer in Quebec and Saskatchewan, as well as in northeastern US.