# Diseased deer may pose risk to humans



## Tom Morang (Aug 14, 2001)

Diseased deer may pose risk to humans

Experts investigate link between infected venison and deadly brain illness

By JOHN FAUBER
of the Journal Sentinel staff
Last Updated: April 28, 2002


Six years ago, D. Kevin Boss died of a rare disease, a degenerative disorder that seemed to dewire the brain of the computer engineer, circuit by circuit.

The death of the former Minneapolis resident from Creutzfeldt-Jakob disease (CJD) otherwise might be unremarkable except for this: Boss got the disease at an unusually young age, 39, and he regularly consumed venison, including deer meat from Wisconsin.

Last month, chronic wasting disease, an always-fatal brain disorder that affects deer, elk and other cervids, was found in the Wisconsin deer herd. The disease is similar to Creutzfeldt-Jakob disease, an always-fatal brain disorder that affects several hundred people in the U.S. every year.

No one is saying that Boss got Creutzfeldt-Jakob disease from eating infected venison. In fact, such a case has never been established in medical science.

But the emergence of chronic wasting disease in deer in Wisconsin and other states has raised questions about whether eating meat from infected deer can cause deadly brain illness in people.

It's an area that scientists now are actively investigating.

Already, several red flags have been raised.

A variant form of Creutzfeldt-Jakob disease has been linked to the large-scale outbreak of bovine spongiform encephalopathy (BSE), also known as mad cow disease, in cattle herds in Europe.

Bovine spongiform encephalopathy has been tied to the deaths of more than 100 people since 1995. It is believed that those people became ill after eating beef from infected cattle.

Could a similar story be unfolding with deer meat and people?

"We really don't know," said Piero Antuono, a professor of neurology at the Medical College of Wisconsin who has autopsied the brains of Creutzfeldt-Jakob disease patients. "You wonder if there is a connection. "This is very reminiscent of the BSE story in England in 1986 and '87 when we didn't know."

In October 2001, a study in the journal Archives of Neurology reported on the cases of three relatively young individuals who contracted CJD and who also had been deer hunters or had regularly eaten venison.

The three individuals, who were from Maine, Oklahoma and Utah, all were under the age of 30 and came down with the disease between 1997 and 2000. The vast majority of CJD patients get the disease in their 60s and 70s.

The researchers, who included scientists from the U.S. Centers for Disease Control and Prevention, concluded that although the circumstances suggested a connection with chronic wasting disease, they could find "no strong evidence of a causal link."

Such statements are far less emphatic than those made by British officials, who in the mid-1990s tried to assure the public about the safety of beef by having their children eat hamburgers in front of television cameras.

In 1995, then-Prime Minister John Major categorically stated that "humans don't get mad cow disease," only to have his health secretary announce a year later that BSE was spreading from cows to people.

In the U.S., no one is saying that chronic wasting disease can't jump from deer to people.

They point out that the overall incidence of Creutzfeldt-Jakob in the U.S. is about one in a million.

The annual incidence among people under age 30 is about 5 per billion, said Lawrence Schonberger, a medical epidemiologist with the Centers for Disease Control and Prevention. However, if you eliminate cases involving infections caused in medical settings, such as cornea transplants and injections of growth hormones obtained from cadavers, that rate drops to roughly 1 per billion, Schonberger said.

In fact, only four such cases were found in the U.S. between 1979 and 1996.

So three cases of young hunters in just four years is cause for concern.

"There isn't any hard data, but what data there is suggests that humans may be vulnerable," said Michael Hansen, a biologist and senior research scientist with the Consumers Union, which publishes Consumer Reports.

The Union has been pushing the federal government to do more to prevent mad cow disease from entering the U.S. and to limit the spread of other so-called transmissible spongiform encephalopathies, or TSEs, such as chronic wasting disease.

For instance, the Union says stricter rules are needed to ban the feeding of meat from deer and elk possibly infected with chronic wasting disease to other animals such as hogs, poultry and pets. That's because another big fear is that chronic wasting disease may someday jump from deer to another species such as cattle.

In a dairy state such as Wisconsin, that concern is especially relevant.

So far, no such cases have been found.

However, laboratory research suggests that it is possible.

TSE diseases such as chronic wasting are believed to be caused by prions, mutant proteins that have the ability to cause normal proteins to mimic their distorted shape, resulting in a buildup of sponge-like holes in the brain.

Prions are particularly adept at infecting nerve cells such as those found in the brain, spinal cord and eyes.

One reason prions are so feared as infectious agents is that they are highly resistant to heat and other sanitizing methods. It is believed that they can exist in the soil and other locations for years and resurface to infect animals.

Two years ago, Byron Caughey and other researchers at the Rocky Mountain Laboratories in Hamilton, Mont., analyzed prions from deer infected with chronic wasting disease.

If lab tests can be both reassuring and chilling, that's what Caughey, a National Institutes of Health researcher, found.

The analysis showed there was a substantial molecular barrier that helped prevent chronic wasting prions from converting normal human protein to the mutant form. However, despite the barrier, the deer prions ultimately were able to convert human protein to the mutant form.

And it did so with about the same level of efficiency as mad cow prions.

"It is low efficiency . . . but it can happen," Caughey said.

Caughey, who obtained his doctorate from the University of Wisconsin-Madison, also found that mad deer prions converted cattle protein to the mutant form at a slightly higher efficiency than it converted human protein, suggesting that cattle might be more vulnerable than people.

Jim Kazmierczak, an epidemiologist with the Wisconsin Division of Public Health, said that while Caughey's research raises concern, it was done under laboratory conditions that may or may not accurately mimic what occurs in nature.

"I'm not saying it doesn't mean anything," he said. "To me it's not terribly alarming."

He noted that Creutzfeldt-Jakob disease has been around a long time, and the incidence has not changed much. It is still a very rare disease, with only about five new cases a year in Wisconsin.

However, he added, "We just can't reassure people the risk is zero."

State health officials now are on the lookout for suspicious Creutzfeldt-Jakob cases and have asked hospitals to report any such patients under the age of 55.

Several ways to infect
Another disturbing bit of science was presented in March by Stanley B. Prusiner, the University of California at San Francisco researcher who won a Nobel Prize for his study of prions.

Prusiner found that prions linked to mad cow disease were found in the muscles of mice that were experimentally inoculated, suggesting that the mutant agents can exist not just in nerve tissue, but also in meats.

The researchers noted that the pooling of prions in the muscles may vary from species to species. Although disconcerting, the researchers said that does not prove that eating muscle meat from infected cattle causes disease.

The study did not involve prions from infected deer.

However, the report and comments from health officials suggest that there may be several ways that deer prions could infect people.

A bullet fragment could travel through prion-infected nerve tissue and into muscle tissue.

Another possibility is in the processing of meat from diseased deer. Saws and butchering equipment could cut through diseased nerve tissue and then into meat.

Complicating matters further, butcher shop hygiene is a far cry from the strict hospital standards required when invasive procedures are done on CJD patients.

Prions from CJD are so infectious that rigorous rules are followed when doing autopsies on the brains of CJD patients.

A 1999 World Health Organization report also noted that there have been several cases of people being infected after coming into contact with contaminated neurosurgical instruments. Cornea transplants also have infected people.

For surgical and other invasive procedures, "Persons with confirmed or suspected TSEs are the highest-risk patients," the report warned. "They must be managed with specific precautions."

Lab work needed
As far back as 1986, studies had suggested a possible link between exposure to deer and the risk of Creutzfeldt-Jakob disease.

That year, a small study involving 26 CJD patients by researchers at Temple University and the National Institutes of Health found that exposure to deer through a hobby such as hunting resulted in up to a ninefold increased risk for the disease.

Chronic wasting disease was first recognized by biologists in Colorado deer during the 1960s.

Ultimately, establishing a strong link between chronic wasting disease and CJD will take extensive lab work.

Such work now is going on at the National Prion Disease Pathology Surveillance Center at Case Western Reserve University in Cleveland.

For several months, researchers there have been looking for molecular similarity between infected deer prions and prions from people who have died from CJD.

It probably will be a couple months before any results are known, said Shu Chen, an assistant professor of pathology at the university.

In the meantime, deer hunters and widows of CJD patients can only wonder.

Linda Boss Price, whose husband, D. Kevin Boss, died of CJD in 1996, said it never occurred to her that there might be a connection to chronic wasting until the disease was found in the Wisconsin deer herd last month.

She said her brother hunted deer in Minnesota and Wisconsin, mainly in Barron County, and often supplied the couple with deer meat. Her husband was a bird hunter and often returned the favor by giving his brother-in-law pheasant.

The couple regularly ate venison in the form of steaks, chops and sausage.

Then, in 1994 he started having problems.

First he had trouble using his computer keyboard. He lost verbal skills. He couldn't feed himself. He would walk outside in the winter without pants on.

"It was like a real fast Alzheimer's," said Boss Price, who has since remarried. "It was like his brain was disconnecting."

Eventually, he had problems swallowing and breathing. He died in a nursing home two years after the first symptoms appeared. He was 41.

She said she has no clue how her husband got sick or whether it was related to chronic wasting disease.

But, she said, "He was far too young for it."


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## sadocf1 (Mar 10, 2002)

In England during the Mad Cow epidemic, to assure the public that beef was safe to eat- to protect the livestock industry with no regard for public health- John Major and the Minister of Agriculture scarfed hamburgers on public TV.
From the Rocky Mountain News, Oct. 12, 2001
Visitors to Elkfest 2001 in Estes Park this weekend will be greeted with 1,400 free barbecue patties of farm elk, courtesy of the Colorado Elk Breeders Association.
It is USDA APPROVED, said Jan Forrest of the Anita Grande elk ranch near Del Norte. "AND IT'S CWD NEGATIVE''
The meat will come from farm elk, some possibly from herds in which CWD has been detected, said Ron Walker, president of the breeders association. However, none is from an infected animal, he added.
"It's healthier than what you get when you hunt in the wild,''Walker said. He said he expects long lines of people wanting to get a taste of "the healthiest food you can have''
As Yogi would say "its deja vu all over again''
Industry must be protected- thats where the money is!


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## Steve (Jan 15, 2000)

This is most definitely the most scary thing to sportsmen in this state that I can remember. You can talk about big lake fish contaminated with chemicals, but at least with those eating one probably won't kill you. With an CWD infected deer, it sounds like it could.


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## sadocf1 (Mar 10, 2002)

Scientists at the Centers for Disease Control and Prevention in Atlanta say there have been no known cases of elk or deer transmitting CWD to humans. There will be increasing media releases - scare tactics- to promote public perception of the possibility of human infection.
WE SAW THIS HERE IN MICHIGAN. REMEMBER THE HIGHLY INFECTIOUS, DEADLY, DEVASTATING DISEASE- BOVINE TB??
THIS IS STANDARD PR PROPAGANDA TO PROMOTE FUNDING!!
FUNDING IS NECESSARY, PROBABLY THE MOST IMPORTANT INGREDIENT FOR ANY GOVERNMENT PROGRAM.
THERE WILL BE MANY STATE AND FEDERAL PROGRAMS TO ADDRESS THE CWD PROBLEM.
We fervently hope there will be no human infection, and if it does occur hopefully will be limited to a few cases


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## Tom Morang (Aug 14, 2001)

Sadocf1, it seems to me that you are sending mixed messages and are intentionaly pointing in many directions within your posts. What is it you are trying to say......exactly................tm


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## Pinefarm (Sep 19, 2000)

Sadocf1, are you implying that the WDNR is going to wipe out the deer herd, the economies of many small towns, and gut their own revenue by a huge loss in license sales in order to get some funding? If there's the fear that people can get some form of mad cow by eating or dressing out a deer, they won't be able to give those tags away. Imagine what would happen to the WDNR if they had a 90% drop in deer license sales for the next five years. I'm not trying to pick a fight, but I think you're looking at the nightmare of CWD through fairly jaded glasses. Just to lighten things up...they may want some extra funding, as long as the helicopters they'll be buying are going to be black helicopters! LOL


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