Outdoors: CWD experts address first meeting of advisory committee

Tim Eisele  —  8/22/2007 10:46 am

Why should we care?

That was a rhetorical question asked by Scott Craven, professor of Wildlife Ecology at UW-Madison, in leading off the second CWD Stakeholder Advisory Committee meetings in Madison last Saturday.

The meeting, held at Lowell Inn and Conference Center on the UW-Madison campus, drew a surprisingly small public attendance, less than 10 people. However, the reason for the meeting was for the 16-member committee to hear from experts about what is known about chronic wasting disease.

The committee will meet monthly between August and January and then come up with recommendations for the DNR on how it should change its CWD management program.

The meetings are open to the public and, theoretically, this would have been an important meeting for members of the public who cared to attend and learn from experts directly, with the opportunity to question them following their presentations.

Craven said that he was influenced by CWD both personally and professionally. He participated in a deer hunting camp located just six miles from where the first three CWD-positive deer were shot in the 2001 deer hunting season. During the next three years that deer hunting camp disappeared as hunters moved on. He and his son have since killed two deer that turned out to be CWD positive.

"I obviously care for both personal and professional reasons, but this issue is just not on people's radar screen like it was three years ago," he said. "One of the most important challenges that you face, as liaisons to groups of citizens and hunters, is to bring that back."

Craven said the discovery of CWD followed a long period of general satisfaction of deer management and deer hunting opportunities. Until CWD was discovered, deer hunting couldn't get any better. Hunter numbers were high, the harvest was 500,000 every year and people knew about the trophy potential of several Wisconsin counties.

"Then all of a sudden on that fateful February day in 2002, CWD was discovered and the world of deer and deer hunting in the state changed very dramatically," Craven said. "Even though deer are only one of about 500 vertebrate species in the state, they remain incredibly important."

Deer have great economic potential, plus social and recreational values. Though they can cause environmental complications, such as deer/vehicle collisions and crop damage, Craven said these problems were on their way to being managed.

But, when the discovery of CWD was announced, there was confusion, concern and anxiety.

"The response from the DNR was immediate and firm, and although that has caused anxiety over time I don't think it could have been done any other way," Craven said. "Surveys were conducted to find the scope of the problem, teams set up to handle the science, public health aspects (if any) communications and field management all over a weekend."

Some of the plans were not palatable to some landowners and hunters within the area affected by CWD. Talk of deer eradication, anxiety over venison safety, constantly changing hunting regulations, and the uncertainty over many aspects of CWD caused much concern and resistance to DNR actions.

Five years after the discovery of CWD, Craven said that millions of dollars and many human resources were expended, a Herculean effort to reduce deer numbers, and scientists have learned much about CWD.

"But CWD is still present and it has been found over a much larger area in southern Wisconsin and northern Illinois," he said. "Many deer remain on the landscape. Progress is slow, but there has been progress."

Craven believes people underestimated the passionate response to the devastating impact of CWD on Wisconsin's rich deer hunting traditions. In some cases it has been divisive, pitting neighbor against neighbor.

Craven said that he believes that people do care, but that CWD must be brought back on the radar screen for the average hunter and landowner.

"Deer are too important to stand idly by and watch CWD run its course whatever course that may be," he said. "Most experts feel CWD can only get worse. If they are correct, the finger pointing and accusations that will occur in 10, 20 or 30 years will be far worse than the current unfortunate situation."

"There really is no choice, we have to care, and we have to act on the best information and advice we can muster from any conceivable source," he said. "For people to care, there must be hope and for that, people must believe that a solution is possible and I believe that to be the case."

Craven asked the committee to base their opinion on facts and not on rumors. This meeting was a presentation of facts by the experts and the committee needed to blend its opinion and perspectives with the facts to come up with a set actions that people can get behind.

Still lots of unknowns: Jim Kazmierczak, epidemiologist with the Wisconsin Division of Public Health, gave the CWD Advisory Committee a primer on prion diseases, or Transmissible Spongiform Encephalopathies. They are caused by abnormal prions and include: scrapie in sheep and goats; mink transmissible encephalopathy; Bovine Spongiform Encephalopathy otherwise known as "mad cow disease" in cattle, CWD in deer and elk and Creutzfeldt-Jakob Disease (CJD) in humans.

He noted that CJD is not found more frequently in states where chronic wasting disease occurs in wildlife.

"And, according to the World Health Organization there is no scientific evidence that CWD causes human illness," Kazmierczak said. He went on to talk about the species barrier, saying that the CWD prion is very inefficient at converting the normal human prion into an abnormal form.

All of the research is reassuring that CWD can not jump the species barrier, he said, but there still are some concerns, such as:

** Saliva and blood from CWD positive deer have been shown to be infectious for other deer.

** Muscle tissue from CWD-infected deer has been found to contain infectious prions.

** Passage of prions through intermediary hosts has been shown to infect other species.

Chad Johnson, assistant scientist in the UW-Madison School of Veterinary Medicine, talked about CWD risks to other species, reporting that a moose was diagnosed with CWD in 2005 and picked up the disease in the natural environment.

Whether CWD can be transmitted to domestic animals is under research. Johnson said that, so far, there have been no clinical signs of CWD in cattle that were inoculated with CWD. However, it can not be concluded that it can't happen.

Researchers know that raccoon, opossum, dog, skunk, coyote, cat, fox and mice all eat deer carcasses. Tests are being done to see if they are susceptible to CWD.

Joel Pedersen, associate professor of Soil Science at UW-Madison, emphasized that if abnormal prions get into the environment they will not go away rapidly. He noted a study of scrapie in Iceland where a new flock of sheep came down with scrapie 16 years after the diseased original flock was eliminated.

Tim Eisele  —  8/22/2007 10:46 am