CWD Risk Assessment and Surveillance Plan

Principal Investigator: Krysten Schuler

Department of Population Medicine and Diagnostic Sciences
Sponsor: Tennessee Wildlife Resources Agency
Grant Number: 17-55318
Title: CWD Risk Assessment and Surveillance Plan
Project Amount: $28,200
Project Period: July 2017 to June 2018

DESCRIPTION (provided by applicant): 

Chronic Wasting Disease (CWD) is a progressive, fatal, degenerative neurological disease of captive and free ranging deer, elk, and moose. First identified in research deer in Colorado in the 1960’s, it has now spread to wild and captive deer and elk in 24 states and Canada. In locations where it has become established, the disease has been detrimental to population health. In Wyoming where the disease is endemic, prevalence rates have reached over 50% in some areas. CWD-infected deer don’t live as long as uninfected deer, they may be more vulnerable to predators, and heavily infected deer populations can see population declines over time.

States’ experience has shown CWD is exceptionally difficult to manage in captive and wildlife populations. Deer or elk infected with CWD may shed prions, but exhibit no symptoms for a year or more. Prions are also extremely resilient in the environment; they may remain infectious for at least 16 years. CWD prions are almost impossible to remove because of their persistence in the environment; they bind to soil and are taken up into plant tissues. There is no vaccine or treatment for this disease, and it is always fatal. Early detection provides the best opportunity for intervention by wildlife managers. Therefore, proactive prevention efforts and rapid response to disease outbreaks are critical for disease management.

CWD monitoring in Tennessee began in 2002 and has included testing of approximately 10,000 deer and elk. As of 2017, CWD has not been detected. TWRA recognizes that prevention efforts, monitoring, and early detection are critical for disease management. To increase the likelihood of early detection, sampling and testing should be focus on geographic areas of highest disease introduction risk and sex and age distributions most affected. Risk of disease introduction and spread may be increased with movement of infected deer, live or dead, and their parts and fluids.