First evidence of the COVID-19 virus in Canadian wildlife in the wild: White-tailed deer infected with SARS-CoV-2.
For the first time since the beginning of the COVID-19 pandemic, the SARS-CoV-2 virus has been detected in free-ranging animals in Canada. Last November, the analysis of samples taken from three white-tailed deer (Odocoileus virginianus) from the Estrie region of Quebec revealed the presence of the virus responsible for COVID-19. These white-tailed deer were sampled at a large game recording station between November 6 and 8, 2021 as part of a monitoring activity put in place by the Ministère de la Forêt de la Faune et des Parcs. The positive animals appeared to be in good health and did not show clinical signs. Detection of the virus has been confirmed by the National Centre for Foreign Animal Disease of the Canadian Food Inspection Agency.
This discovery is not surprising, because the presence of SARS-CoV had already been detected in white-tailed deer in several regions of the United States. It is believed that wild deer are infected via humans, since the viral variants isolated from humans matched variants present in nearby human populations during the same period. White-tailed deer can potentially become infected either through direct contact (supplemental feeding, research activities) or through indirect contact by sharing peri-urban habitat with humans. However, the route of transmission of the virus to wildlife remains uncertain. White-tailed deer appear to develop a subclinical infection (no evidence of disease), but can still transmit the virus to other deer effectively.
SARS-CoV-2 is already responsible for multiple outbreaks in captive wild animals, especially in big cats and non-human primates in zoological institutions. However, there is still little data on the importance of the virus in wild animal populations. At this time, there is no data that suggest that white-tailed deer are able to infect other species, such as humans. However, it is still recommended to take basic protective measures when in contact with a white-tailed deer (gloves, mask and protective glasses).
In Canada, a continuous surveillance program targeting wild species potentially susceptible to this infection is underway with the collaboration of the various regional centres of the CWHC. This surveillance is part of the actions to fight against the current pandemic, in order to identify a natural reservoir.
For more information on the subject:
Chandler, J., Bevins, S., Ellis, J., Linder, T., Tell, R., & Jenkins-Moore, M. et al. (2021). SARS-CoV-2 exposure in wild white-tailed deer (Odocoileus virginianus). Proceedings of the National Academy of Sciences, 118(47), e2114828118. doi: 10.1073/pnas.2114828118
Cool, K., Gaudreault, N., Morozov, I., Trujillo, J., Meekins, D., & McDowell, C. et al. (2021). Infection and transmission of ancestral SARS-CoV-2 and its alpha variant in pregnant white-tailed deer. Emerging Microbes & Infections, 1-39. doi: 10.1080/22221751.2021.2012528
Damas, J., Hughes, G., Keough, K., Painter, C., Persky, N., & Corbo, M. et al. (2020). Broad host range of SARS-CoV-2 predicted by comparative and structural analysis of ACE2 in vertebrates. Proceedings of the National Academy of Sciences, 117(36), 22311-22322. doi: 10.1073/pnas.2010146117
Environment and Climate Change Canada (2021, December). First case of SARS-CoV-2 detected in Canadian wildlife. https://www.canada.ca/en/environment-climate-change/news/2021/12/first-case-of-sars-cov-2-detected-in-canadian-wildlife.html
Hale, V. L., Dennis, P. M., McBride, D. S., Nolting, J. M., Madden, C., Huey, D., et al. (2021). SARS-CoV-2 infection in free-ranging white-tailed deer (Odocoileus virginianus). Biorxiv.
Sharun, K., Dhama, K., Pawde, A., Gortázar, C., Tiwari, R., & Bonilla-Aldana, D. et al. (2021). SARS-CoV-2 in animals: potential for unknown reservoir hosts and public health implications. Veterinary Quarterly, 41(1), 181-201. doi: 10.1080/01652176.2021.1921311 Organisation mondiale de la santé animale (OIE) (2021, octobre). Fiche technique : Infection par le SARS-CoV-2 chez les animaux.
Louise Quesnel, Stéphane Lair, CWHC – Quebec
