MICHIGAN SURVEILLANCE AND RESPONSE PLAN FOR CHRONIC WASTING DISEASE (CWD) OF FREE-RANGING AND PRIVATELY OWNED CERVIDS, MI DNR, 2002, revised 2012
2. CWD is transmitted between animals by direct contact with infectious saliva, respiratory aerosols, urine, and feces. Infected animals are infectious for other
animals before they appear sick. Infected animals inevitably succumb, although the amount of time that takes to happen can vary from months to years.
3. CWD is also transmitted indirectly from contaminated items in the environment such as soils where it persists for decades.
Where the disease becomes established, environmental contamination likely drives CWD outbreaks perpetually, and may be the most critical factor limiting their control. Substantial environmental contamination with CWD may effectively define the threshold for when the disease is ‘established’.
Chronic Wasting Disease: Natural Deer Urine Attractants Illegal in Virginia, Virginia Department of Game and Inland Fisheries, July 2015
- The infectious proteins (i.e., prions) known to transmit CWD have been found in the urine, feces, and saliva of infected individuals. In experiments conducted in Colorado mule deer were able to catch CWD with no exposure other than the urine, feces, and saliva of infected individuals.
- To make these commercial scents, urine from captive elk and/or deer kept outside of Virginia is collected over a grate system that does not prevent contamination from either feces or saliva. Many of these facilities are located in areas or states with CWD. There is no USDA-approved live animal test for CWD, nor is there a way to test urine for CWD prions once it has been collected, and so the collection facility has no way of knowing that their deer are CWD free.
- The “urine” product is not treated chemically or with heat to kill the infectious proteins because these treatments would also secondarily destroy the desired scent characteristics.
- The infectious proteins causing CWD are extremely resistant to degradation and may persist in the environment for years in contaminated soil, thereby posing a disease transmission risk to deer for extended lengths of time.