From Deer-to-Deer: SARS-CoV-2 is efficiently transmitted and presents broad tissue tropism and replication sites in white-tailed deer

Authors: MARTINS, MATHIAS - Cornell University; Boggiatto, Paola; Buckley, Alexandra; Cassmann, Eric; Falkenberg, Shollie; CASERTA, LEODARDO - Cornell University; FERNANDES, MAUREEN - Cornell University; Kanipe, Carly; Lager, Kelly; Palmer, Mitchell; DIEL, DIEGO - Cornell University

Submitted to: PLoS Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2022
Publication Date: 3/21/2022
Citation: Martins, M., Boggiatto, P.M., Buckley, A., Cassmann, E.D., Falkenberg, S.M., Caserta, L.C., Fernandes, M.H., Kanipe, C.R., Lager, K.M., Palmer, M.V., Diel, D.G. 2022. From Deer-to-Deer: SARS-CoV-2 is efficiently transmitted and presents broad tissue tropism and replication sites in highly susceptible white-tailed deer. PLoS Pathogens. 18(3). Article e1010197. https://doi.org/10.1371/journal.ppat.1010197.
DOI: https://doi.org/10.1371/journal.ppat.1010197

Interpretive Summary: The high susceptibility of white-tailed deer (WTD) to SARS-CoV-2, their ability to transmit the virus to other deer, and the recent findings demonstrating widespread SARS-CoV-2 infection in wild WTD populations in the US underscore the need for a better understanding of the infection and transmission dynamics of SARS-CoV-2 in this potential reservoir species. Here we investigated the transmission dynamics of SARS-CoV-2 over time and defined the major sites of virus replication during the acute phase of infection. Additionally, we assessed the evolution of the virus as it replicated and transmitted between animals. The work provides relevant information on the infection dynamics of SARS-CoV-2 in WTD, an animal species that - if confirmed as a new reservoir of infection - may provide many opportunities for exposure and potential transmission of the virus back to humans.

Technical Abstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus Disease 19 (COVID-19) in humans, has a broad host range, and is able to infect domestic and wild animal species. Notably, white-tailed deer (WTD, Odocoileus virginianus) the most widely distributed cervid species in the Americas was shown to be highly susceptible to SARS-CoV-2 with reported natural infection rates approaching 40% in wild WTD populations in the U.S. Thus, understanding the infection and transmission dynamics of SARS-CoV-2 in WTD is critical to prevent future zoonotic transmission to humans and for implementation of effective disease control measures. Here, we demonstrated that following intranasal inoculation with SARS-CoV-2, deer fawns shed infectious virus up to day 5 post-inoculation (pi), with high viral loads shed in nasal and oral secretions. This resulted in efficient deer-to-deer transmission on day 3 pi. Consistent with lack of infectious SARS-CoV-2 shedding by inoculated animals on days 6 and 9 pi, no transmission was observed to contact animals on these days. We have also investigated the tropism and sites of SARS-CoV-2 replication in WTD. Active virus replication was observed in respiratory-, lymphoid-, and central nervous system tissues, indicating broad tissue tropism and multiple target sites of virus replication during acute infection. The study provides important insights on the infection and transmission dynamics of SARS-CoV-2 in WTD, a wild animal species that is highly susceptible to infection and with the potential to become a reservoir for the virus in the field.