Table 10.

Transmission pathways of SARS CoV‐2 for different scenarios in white‐tailed deer (WTD), probability of transmission and related preventive and control measures

Possible transmission pathways	Risk factors/periods/areas	P of transmission	Possible monitoring approach	Potential preventive and control measures in/for animals	Potential preventive and control measures in humans
Human > deer In the next 12 months, what proportion of the WTD in the EU will get infected with SARS‐CoV‐2 due to contact with infected people?	Hunting season (e.g. contaminated baiting, feeding) Outdoor activity Occupational exposure (e.g. forest workers, deer farmers) Proximity to urban settings (wastewater, rubbish) Epidemiological situation (level of infection) in general population	Very low to low, < 10%–33% quality of evidence: moderate (Palmer et al., 2021; Vandegrift et al., 2022)	To set up integrated monitoring of relevant species (Cardoso et al., 2021)	Good hunting practices (avoid feeding or baiting) Safe disposal of garbage and use of animal‐proof containers	Testing and symptom monitoring PPE for close contact (e.g. face masks) No contact with live wild animals for people with symptoms Wastewater management Avoid unnecessary contact in general. Vaccination of people in contact with live animals
Reasoning to support estimation of P of transmission: several variants circulating among humans spilled over to deer, although no case in EU, the majority of white‐tailed deer WTD in the EU are in Finland, where the circulation of SARS‐CoV‐2 has been among the lowest in the EU all through the pandemic. Nevertheless, this could be linked to the diversity of hosts and the limited and generally non‐systematic sampling.
Deer > deer In the next 12 months, out of SARS‐CoV‐2 infected WTD in the EU, what is the proportion that will transmit the infection to one or more WTD?	Population density Mating season Epidemiological situation (level of infection) in general population	Low to high, 33–99%; quality of evidence: moderate for WTD (Hale et al., 2021; Kotwa et al., 2022), but very limited evidence for European wild ruminants Reasoning: there is clear maintenance of infection in WTD populations in North America	Monitoring group sizes and contact rates	Avoid aggregation of susceptible animals at focal points such as feeding sites (Gortazar et al., 2015) To avoid situations of overabundance of susceptible wildlife	Not applicable
Deer > humans In the next 12 months, out of SARS‐CoV‐2 infected WTD in the EU, what is the proportion that will transmit the infection to one or more humans?	Hunting season Hunting practices and carcass handling Outdoor activity Population density of deer Closer/more frequent contacts in protected or urban areas Epidemiological situation (level of infection) in general population	Very low, < 10% quality of evidence: moderate Reasoning: a report of SARS‐CoV‐2 WTD‐adapted lineage with epidemiological link to a human case may support the hypothesis of deer to human transmission (Pickering et al., 2022b)	Testing of found dead animals, or shot/road kill animals Integrated monitoring	same as above pathway, human to deer	PPE when managing fresh carcasses Hand hygiene Testing Vaccination of people in contact with live animals (hunters, visitors, etc.)