The Wisconsin Division of Public Health today released completed test results related to the investigation into the fatal cases of degenerative neurological illnesses in three men who consumed wild game served during a series of feasts.
The test results announced today indicate that Wayne Waterhouse, a northern Wisconsin resident who died in 1993, did not have Creutzfeldt-Jakob disease (CJD) or any other evidence of prions or prion-related illness. Results already made public indicated that another of the patients, Roger Marten, a northern Wisconsin resident who died in 1993, also did not have CJD or any other evidence of prions or prion-related illness. Only one of the three men, James Botts, a Minnesota resident who died in 1999, had a confirmed diagnosis of CJD.
“These results are important because if all three men had developed a rare disease like CJD, such a cluster would suggest a common source of exposure,” said Dr. Jeffrey Davis, Wisconsin State Epidemiologist for Communicable Diseases, in reporting the findings. “Thanks to a new testing process not available at the time of the initial diagnosis of CJD in these patients, we are able to demonstrate the absence of prions in the brain tissues of two of the patients. Therefore, these three cases cannot be attributed to a common source of illness.”
The current investigation, conducted by the Division of Public Health and the U.S. Centers for Disease Control and Prevention, was initiated after reports surfaced that rare degenerative neurological diseases had occurred in three acquaintances who shared meals of wild game in northern Wisconsin. The reports generated considerable public interest due to the concern that these illnesses might somehow be linked to chronic wasting disease (CWD) of deer and elk.
“These findings are consistent with earlier statements by the CDC and the World Health Organization that the CWD prion has not been shown to cause human illness,” Dr. Davis added. “They also illustrate the ongoing need to apply the most current scientific techniques to the important issue of understanding CWD and other prion-related conditions.”
Specimens of brain tissue from each of the three men had been collected during the individuals’ autopsies. The tissues were recently forwarded to the National Prion Disease Pathology Surveillance Center in Cleveland, Ohio, where pathologists examined the specimens for evidence of CJD and the presence of abnormal prion proteins which cause the illness. This pathology center was established during 1996-1997 by CDC in collaboration with the American Association of Neuropathologists to enable state-of-the-art laboratory investigation of physician-diagnosed and suspected cases of prion disease in the United States.
Creutzfeldt-Jakob disease is a fatal degenerative brain condition of humans believed to be caused by an abnormally-shaped protein called a prion. It occurs at a rate of about one case per million people per year throughout much of the world, and was first described in the 1920s. Chronic wasting disease in deer and elk is also believed to be caused by a prion and produces lesions in the brain, but the deer CWD prion has not been shown to affect humans.
Dr. Davis reiterated that while these new results are reassuring, it is still impossible to say with absolute certainty that the CWD prion will never cause human illness. As a precaution, he continues to advise that hunters process their venison in a safe manner and not ingest tissues where the CWD prion is known to concentrate. These tissues include brain, spinal cord, eyes, lymph nodes and spleen. The Wisconsin Department of Agriculture, Trade, and Consumer Protection has issued recommendations on processing deer. These can be found on their website at http://datcp.state.wi.us/ah/agriculture/animals/disease/chronic/pdf/venison_safety_2side.pdf