Interim Findings on Cluster of Neurologic Diseases in Hunters

(MADISON, September 12, 2002) – The Wisconsin Division of Public Health released information today on the status of an investigation into fatal cases of degenerative neurologic illnesses in three men who consumed wild game. The 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 neurologic diseases had occurred in three acquaintances who shared meals of wild game. The meals were served during multiple gatherings that were held in northwestern 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. The names of the three men have been previously released by the media.

Jeffrey Davis, MD, Wisconsin State Epidemiologist for Communicable Diseases, stressed that the investigation is still ongoing, but shared the following information.

The first component of the investigation is a re-examination of brain tissue collected from the patients during their autopsies. Two of the patients died in 1993 and the third died in 1999. Tissue samples from all three men were recently forwarded to the National Prion Disease Pathology Surveillance Center in Cleveland, Ohio. Pathologists there are examining the tissue specimens for evidence of Creutzfeldt-Jakob Disease (CJD) and the presence of abnormal prion protein.

Test results from the National Prion Disease Surveillance Center are complete on one of the three sets of samples. Pathologists concluded that the samples from Roger Marten, whose death in 1993 was attributed to Pick’s disease, showed no evidence of CJD and did not contain any detectable prions.

Creutzfeldt-Jakob Disease is a fatal degenerative brain condition of humans caused by an abnormally-shaped protein called a prion. It occurs at a rate of about one case per million people throughout the world, and was first described in the 1920s. Chronic wasting disease in deer and elk is also caused by a prion and produces brain lesions similar to CJD in humans, but the deer CWD prion is not the same agent as the human CJD prion. The CWD prion has never been shown to cause human illness.

Public health investigators are also looking into the wild game feasts that took place from the late 1970s into the 1990s, and which were hosted by one of the deceased hunters. Based on information gathered to date, an estimated 75 people attended these gatherings over the years. Investigators have been able to contact 43 individuals so far who were questioned about their state of health to determine whether other cases of rare neurologic illnesses had occurred in this group. No such illnesses were discovered among these individuals. In an effort to determine whether the game that had been served had been harvested in areas where CWD is known to occur, attendees at the feasts were also asked about the sources of venison and elk meat that was brought to these events.

“Due to the long incubation period of CJD, the potential exposures of interest would have occurred in the late 1970s and early to mid- 1980s”, said Dr. Davis. “So we were particularly interested in where game had been harvested in the western states of Colorado and Wyoming, since CWD is known to have been endemic in those states for several decades.” Of the feast attendees who could recall where the game had been harvested, none have identified areas where CWD is known to have been present.

Although the investigation is ongoing, the findings to date are consistent with statements by the CDC and the World Health Organization that CWD has not been shown to be a human pathogen. As a precaution, health officials continue to advise that hunters process their venison in a safe manner and not ingest tissues where the CWD prion is known to concentrate. These 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

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