The first potential case of deer transmitting the novel coronavirus to humans was reported in Canada. Researchers identified the genome cluster of SARS-CoV-2, the Corona virus that causes COVID-19 that mutated in white-tailed deer.
This study underscores the potential of deer to act as an animal reservoir for viruses. The team of scientists analyzed 300 samples collected in the November-December 2021 range from white-tailed deer in Southwest and Eastern Ontario. They found that 17 deer in Southwestern Ontario tested positive for SARS-CoV-2.
"When the researchers sequenced the genomes of five viral samples, they identified a "new and very different lineage from SARS-CoV-2," the researchers wrote, quoted from Live Science.
A lineage is a group of viruses that are closely related to a common ancestor, according to the US Centers for Disease Control and Prevention (CDC). SARS-CoV-2 itself has many lineages. This lineage has 76 mutations compared to the original version of the virus identified in Wuhan, China. Further analysis indicated that the viral lineage may have evolved in animals since late 2020.
Next, the researchers compared the viral genomes found in deer with those found in humans in the area. They identified a person infected with a genetically similar strain of SARS-CoV-2.
This person lives in Southwest Ontario and is known to have been in close contact with deer, so it seems plausible that the deer transmitted the virus to humans in this case. However, the researchers note that the limitations of the data obtained make it difficult for them to definitively link human and reindeer COVID-19 cases.
"Although previous studies have shown that COVID-19 can spread from humans to deer, and in deer populations, this is the first evidence of deer-to-human spread," the authors said.
So far, the case appears to be an isolated case. The researchers found no evidence of cases in other humans from this lineage. Preliminary analysis by the researchers also suggests that the mutation is unlikely to have a major effect on the ability of the COVID-19 vaccine to protect against this viral lineage.
The researchers emphasize the need for surveillance of SARS-CoV-2 in deer and other animals to identify reservoirs capable of driving transmission and evolution of the virus.
"Until we know more, people who hunt, work or handle wildlife should take precautions to prevent the potential spread of the virus," Canada's public health agency said.
