Submitted to: Emerging Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2009
Publication Date: 5/1/2009
Citation: Angers RC, Seward TS, Napier D, Green M, Hoover E, Spraker T, et al. 2009. Chronic wasting disease prions in elk antler velvet. Emerg Infect Dis 15(5):696-703.
Interpretive Summary: Chronic wasting disease (CWD) is a fatal neurologic disease of deer and elk in the United States and Canada. The disease is associated with accumulations of infectious proteins in the brain, nervous system, blood, and a limited number of other tissues. In this study, the investigators examined elk antler velvet, the covering that grows on elk antlers every year. Antler velvet is rich in blood and nervous supply and may represent a source of infectious material as the velvet is shed every year. Antler velvet and brain tissue from four infected elk was examined by immunohistochemistry and biochemical methods, with no evidence of the abnormal prion protein in antler velvet. The same preparations were tested in genetically engineered mice susceptible to CWD. Mice in both inoculated groups developed prion disease. This finding demonstrates that antler velvet from CWD infected elk contain infectious material and may represent a risk material to other elk.
Technical Abstract: Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy or prion disease of captive and free ranging white tailed deer, mule deer, Rocky Mountain elk and moose in the some parts of the United States and Canada. The presence of the disease has sharply curtailed movement of captive animals and reduced the domestic or international market for some cervid by-products. The disease appears to be transmitted by Rocky Mountain elk relatively late in the disease course, but the sources of the infectious material remain undefined. Brain and lymphoid tissue contain the highest levels of the abnormal prion protein, the marker for disease, and transmission in white tailed deer can be accomplished by blood transfusion from experimentally infected deer to naive deer. In this study, the investigators examined the transmission potential of antler velvet, a highly vascularized and innervated epidermal tissue covering the growing antler. Antler velvet is shed each year and is widely used as a nutritional supplement. Genetically engineered mice susceptible to CWD were inoculated with homogenates of paired brain and antler velvet from 4 elk with CWD. Mice in both groups developed a transmissible spongiform encephalopathy. These findings demonstrate prion infectivity accumulates in antler velvet and may have impact on marketing of this product.