Questions and Answers: 

SARS-CoV-2 Surveillance 

in Free-Ranging Deer and 

Other Cervids 

Summary

In November 2021, the U.S. Department of Agriculture’s 

(USDA) Animal and Plant Health Inspection Service 

(APHIS) began sampling wild white-tailed deer 

(Odocoileus virginianus) for active infection of SARSCoV-2 (SCV-2) virus and the presence of antibodies 

indicative of prior infection. In fall 2022, APHIS expanded 

disease surveillance efforts to investigate the presence 

of SCV-2 in other members of the deer family (cervids). 

This approach to monitoring and evaluation of cervid 

populations across the United States aligns with APHIS’ 

American Rescue Plan Strategic Framework.

What did APHIS study?

Federal and academic researchers have documented 

that captive and wild WTD can be infected with SCV2 and transmit the virus to other WTD. To better 

understand the susceptibility of wild WTD to SCV-2, 

APHIS’ Wildlife Services (WS) Program conducted a pilot 

serological study in four States. WS collected blood 

samples from a total of 385 WTD between January and 

March 2021. Approximately 40 percent of those samples 

contained SCV-2 antibodies suggesting that the virus is 

circulating in wild WTD populations in the four States 

evaluated. In March 2022, APHIS’ National Veterinary 

Services Laboratory (NVSL) confirmed the first detection 

of SCV-2 in a wild mule deer (Odocoileus hemionus) from 

Utah. Additional research suggests that other members 

of the cervid family are susceptible to infection by SCV-2.

Is the study ongoing? 

Yes. Given the significant level of detectable SCV-2 

antibodies found in previous studies and the extensive 

populations of cervids across diverse habitats throughout 

the country, APHIS is conducting ongoing surveillance 

to better understand the scale and scope of exposure 

to the virus in cervids. In November 2021, APHIS and 

its partners began a multi-year WTD monitoring and 

surveillance effort funded by the American Rescue Plan 

Act to understand the scope of SCV-2 infection in WTD 

and assess the potential human and animal health risks. 

In October 2022, APHIS expanded disease surveillance 

efforts to investigate the presence of SCV-2 in other 

members of the deer family, including free-ranging mule 

deer, elk, and moose. 

This project is helping us understand if cervids are acting 

as a host or a “reservoir species,” meaning an animal 

host in which the virus can survive in the wild and 

potentially mutate into new variants. We are also looking 

at which SCV-2 variants are circulating and potentially 

emerging in cervids, and the transmission pathways to 

and from cervids, or if pathways exist within other cervid 

populations. Additionally, this project allows APHIS and 

its partners to better understand the impacts of SCV-2 

in cervid populations and how widespread it is in the 

United States.

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www.aphis.usda.gov/onehealth

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How is APHIS conducting this study? 

WS is partnering with State and Tribal wildlife 

management agencies across the country to 

opportunistically collect samples from hunter-harvested 

cervids and/or cervids taken during WS wildlife damage 

management and State agency harvest activities. 

Samples consist of paired swabs, either nasal or oral, 

and whole blood collection on Nobuto filter strips. 

WS’ disease diagnostic laboratory then tests swabs 

by qPCR for the presence of SCV-2 RNA and Nobuto 

strips by surrogate virus neutralization assay for SCV-2 

antibodies. NVSL conducts confirmatory testing of qPCRpositive swab samples. SCV-2 is a reportable disease; 

APHIS reports the first confirmed case of SCV-2 in a new 

species to the World Organization for Animal Health. 

What’s next for this study? 

After the project has been completed or as significant 

milestones are met, APHIS will share a summary on our 

One Health website. 

APHIS will continue to coordinate the nationwide 

collection of samples from cervids through winter 

2023. WS anticipates robust sampling to occur in 

future years, with additional State and Tribal partner 

participation. Future surveillance and analysis of the 

gathered data will be crucial in determining whether 

certain variants are persisting in cervid populations 

and in determining if cervids in the United States are a 

reservoir species for SCV-2. This work will help APHIS 

better understand possible SCV-2 transmission routes, 

and the potential risk these populations may pose to 

people, domestic animals, and wildlife. 

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Why did APHIS do this study? 

Cervids regularly interact with humans, and human 

byproducts, such as wastewater. In urban-suburban 

environments, where both deer and humans may be 

abundant, there is the potential for human-to-deer 

transmission of SCV-2, although the frequency of 

these events is largely unknown. The project aims to 

build the Nation’s capability to detect SCV-2 in cervids 

by strengthening and standardizing procedures and 

processes for sample collection. 

Further, cervids are one of the most economically 

important game species in the United States. Big game 

hunting is a powerful economic contributor, generating 

more than $60 billion annually, much of which cascades 

to local and regional economies across the Nation. An 

estimated 6 million WTD are harvested annually by 

hunters. Beyond economics and hunting, recreation 

involving big game species provides cultural and social 

value that is immeasurable. 

Can people get COVID-19 from deer and other 

cervids? 

We are still learning about SCV-2 in animals, but there 

is currently no evidence that animals, including deer, 

play a significant role in spreading the virus to humans. 

Based on the limited information available to date, the 

risk of animals spreading SCV-2 to people is low. Further 

studies are needed to understand if and how different 

animals could be affected by the virus that causes 

COVID-19 and the role animals may play in the spread of 

the virus. 

How are deer and other cervids exposed to the 

virus? 

We do not know how the deer are exposed to SCV-2. 

It’s possible they were exposed through people, the 

environment, other deer, or another animal species. 

Further studies are needed to better understand this issue.

Resources

USDA APHIS | Cases of SCV-2 in Animals in the United States

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Revised January 2023 | APHIS 11-55-014