The Chronic Wasting Disease Controversy

ConsumerFreedom.Com published a review of concerns about chronic wasting disease in deer and elk (often referred to as “mad deer disease.”) Like Mad Cow Disease and Cruetzefeld-Jakobs, CWD involves prions that cause lesions to form in the brain of deer and elk. The current debate is centered around what, if any, risk the disease poses to human beings.

In deer and elk, the disease was first identified in the late 1970s in deer that were held in captivity. The perception, however, is that the disease has spread rapidly with some studies suggesting that as many as 3 percent of deer in some areas may be suffer from CWD.

A major problem in assessing the extent of the risk to human beings is that no one knows how CWD is transmitted. The Mad Cow epidemic was caused when tissues from the central nervous system and brains from cows were fed back to other cows after the rending process. But CWD is clearly infectious in the wild without requiring such an elaborate transmission method, and has also jumped to elk.

As The Center for Consumer Freedom noted, groups such as the Organic Consumers Association and people like John Stauber, author of Mad Cow USA, are claiming that CWD has already killed humans. They point to four cases of young people who died from CJD.

CJD generally kills people in their 60s and 70s, so several cases of the disease among young adults certainly calls for investigation. The Center for Disease Control ruled out Mad Cow Disease as a possible culprit, at which point Stauber and others pointed out that two of the men who died were hunters and a third victim was the daughter of a hunter.

Stauber told The Wall Street Journal back in May that, “I think that we have to assume the worst of CWD — that it could be even more dangerous and costly than mad cow because of its unique ability to spread through the environment and animal to animal.”

This ignores a couple of salient points. First, Stauber never bothers to mention that the CDC also investigated whether or not exposure to CWD might have caused these individuals’ disease, and concluded that there was “no strong evidence for a causal link” between CWD and the deaths of the four people from CJD.

Moreover, Stauber’s claim that CWD can spread quickly from “animal to animal” is a distortion. Obviously it spreads among deer and elk, but there is apparently a species barrier that keeps it from jumping to other mammals. Cows penned in with deer suffering from CWD, for example, do not contract any sort of prion disease from the deer. Besides, the important issue for human beings is whether or not the disease can spread easily from deer/elk to human beings. So far the answer is no.

Even with Mad Cow Disease there is clearly a high species barrier that makes transmission to humans very difficult. Despite all of the claims that potentially tens of thousands of people would die in Great Britain, the number of actual cases of vCJD in the UK has been very small. Traditional food poisoning is a far higher risk to human beings than Mad Cow Disease.

Second, although researchers at the National Institutes of Health’s Rocky Mountain Laboratory were able to use CWD prions to transform healthy human prions into a deadly diseased form, this transformation turned out to be surprisingly difficult to do even under laboratory conditions.

Rather than the sort of hysteria that Stauber and his ilk promote, a better course is that already adopted by state and federal authorities who are proceeding on numerous fronts to find out once and for all how CWD is spread among deer and elk and what, if any, risk of infection it poses to human beings.

Of course, don’t look for animal rights activists to line up behind such research since it largely involves laboratory research with mice and other animals. In fact, it is fascinating to look at animal rights sites that mention Nobel Prize winner Stanley Prusiner’s ongoing research into prions without even a hint that Prusiner is working with laboratory animals.

Sources:

‘Mad deer’ plague baffles scientists. Antonio Regalado, Wall Street Journal, May 24, 2002.

“Mad Cow”: A Review. Center for Consumer Freedom, July 10, 2002.

Study adds to ‘mad cow’ worries. Lou Kilzer, Rocky Mountain News, March 19, 2002.

Study: Deer with CWD considered edible. Larry Porter, The Omaha World-Herald, April 8, 2002.

The Prion Diseases. Stanley B. Prusiner.

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