Expanding CWD Disease Surveillance Options Using Environmental Contamination at Deer Signposts

Authors

Miranda H. J. Huang, Mississippi State UniversityFollow
Steve Demarais, Mississippi State University
Alejandro Banda, Mississippi State University
Bronson K. Strickland, Mississippi State University
Anna Grace Welch, Mississippi State University
Scoty Hearst, Mississippi College
Stuart Lichtenberg, University of Wisconsin-Madison
Allan Houston, University of Tennessee
Kim M. Pepin, USDA APHIS WS NWRC Fort Collins

ORCID IDs

Huang 0000-0001-8891-9772
Strickland 0000-0002-3119-2514
Lichtenberg 0000-0002-2445-8927
Pepin 0000-0002-9931-8312
VanCauteren 0000-0002-4783-493X

Date of this Version

2024

Citation

Ecological Solutions and Evidence (2024) 5: e12298

doi: 10.1002/2688-8319.12298

Handling editor Dave Augeri

Comments

License: CC BY-NC 4.0

Abstract

1. Environmental surveillance can allow early detection of diseases, which increases management options and can improve disease trajectories. Chronic wasting disease (CWD) in cervids is a significant prion disease that has been spreading across North America since the 1960s, leading to cervid population declines and concern from hunters and state wildlife agencies. White-tailed deer have a unique breeding season behavior called scraping, where they deposit urine and saliva at shared sites. Since both these fluids can contain CWD prions, scrape sites have the potential to serve as sentinel sites for environmental surveillance of CWD.
2. To examine this potential, we used camera traps to monitor deer behavior and collected environmental samples from 105 scrape sites. The 48 km² study site was located at the center of the CWD zone in southwestern Tennessee (United States), where CWD prevalence is ~50%. We also sampled scrapes in northern Mississippi at the leading edge of the same CWD distribution to test the potential for early CWD detection using scrape sampling.
3. From camera data, we identified 218 unique bucks visiting 105 scrapes, with a mean of 12.2 ± 7.5 bucks per scrape (mean ± SD, range 1–39) and individual bucks visiting a mean of 5.9 ± 4.6 monitored scrapes each (range 1–23).
4. Using real-time quaking-induced conversion (RT-QuIC), we detected prion seeding activity in 20% of the soil and 41% of the licking branches of the scrape sites within the CWD study area, and in 25% of the soil and 11% of the licking branches of scrape sites sampled at the edge of the known CWD distribution.
5. Our data show there is environmental prion contamination at scrape sites. This supports the idea that scrapes could serve as early warning sentinel sites for CWD surveillance through testing soil and licking branches for prion seeding ac-tivity, especially in areas with limited access to harvested deer samples.