Monitoring Suspected Links to Chronic Wasting Disease

Alzheimer's Association

April 8, 2003

Researchers from Colorado reported that they had found no evidence to date suggesting that chronic wasting disease had been transmitted from animals to humans. The research team from the Colorado Department of Public Health and the University of Colorado presented their findings at the 55th Annual Meeting of American Academy of Neurology in Honolulu, Hawaii.

The Colorado program is an ongoing surveillance project to investigate certain cases of dementia in people who could have come in contact with elk or deer in regions where chronic wasting disease is fairly common. This disorder in elk and deer is a prion disease, in which abnormally formed prion proteins in the brain lead to the loss of brain cells.

The most common prion disease in humans is Creutzfeldt-Jakob disease (CJD). In Europe, a form of this disease, called variant CJD (vCJD) has been attributed to the consumption of meat from cattle with another prion disease called bovine spongiform encephalopathy, or mad cow disease.

There is no reported evidence that vCJD or some form of the disorder can develop from eating deer or elk with chronic wasting disease. The Colorado surveillance project has been set up to collect data regarding this issue.

To date the team has evaluated two cases of dementia in which the symptoms progressed in a very short time. This rapid decline is common in CJD and vCJD.

The first case was a 52-year-old woman who had worked in a laboratory that tested chronic wasting disease tissues samples. An autopsy confirmed that she did not have abnormally shaped prion proteins and that she had Alzheimer pathology.

The second case was a 25-year-old man who had hunted deer and elk. This individual's mother had died of a dementing illness at the age of 40, but there had been no autopsy to determine the cause. His autopsy showed misshapen prion proteins. However, a genetic analysis showed that he carried a gene mutation for familial CJD.

Therefore, the researchers concluded that they had found no evidence linking the prion disease in elk and deer to prion disease in humans. They noted that the cases studied so far demonstrate the value of thorough autopsy investigations to arrive at a well-documented understanding of this issue.

For more information, please see our chronic wasting disease fact sheet.