Viral outbreak dynamics and evolution in wildlife at the interface with humans

Area of Science:

• Veterinary Virology
• Wildlife Epidemiology
• Zoonotic Disease Research

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been detected in various wildlife species.
• Understanding viral dynamics in animal populations is crucial for managing zoonotic disease risks.

Purpose of the Study:

• To investigate SARS-CoV-2 transmission and persistence patterns in a wild white-tailed deer population.
• To differentiate between deer-to-deer transmission and human-to-deer spillover events.

Main Methods:

• Multi-faceted approach combining serology, traditional disease modeling, individual-based modeling with GPS tracking, and phylogenetic analyses.
• Analysis of deer-derived and human-derived SARS-CoV-2 sequences.
• Assessment of transmission parameters such as R0 and recovery period.

Main Results:

• Serological data confirmed SARS-CoV-2 transmission and persistence in white-tailed deer over seven months.
• Phylogenetic analysis indicated recurring patterns of deer and human viral sequences, suggesting repeated human-to-deer spillover events.
• While deer-to-deer transmission occurs locally, widespread persistence is linked to frequent human spillover.

Conclusions:

• SARS-CoV-2 outbreaks in white-tailed deer are localized and recurrent, primarily driven by frequent spillover from human populations.
• Deer-to-deer transmission plays a role at smaller spatiotemporal scales, but human-to-deer spillover is key for longer-term persistence and broader geographic spread.
• This study highlights the importance of considering human-wildlife interfaces in the epidemiology of zoonotic viruses.