March 17, 2002 The Plain Dealer by D'Arcy EganChronic Wasting Disease (CWD) has been detected in three Wisconsin deer killed by hunters last November, sending shock waves through wildlife management communities from Texas to Ohio.
It was the first time CWD has been discovered east of the Mississippi River. The disease "could spread like wildfire in states such as Ohio that have a high deer density," said Mike Reynolds, a wildlife research biologist with Ohio Division of Wildlife at the Waterloo Wildlife Research Station in New Marshfield, Ohio.
Initially discovered in captive herds in Colorado in the 1960s, CWD was documented in wild mule deer, white-tailed deer and elk in the 1980s. The disease moves quickly through captive herds, but has slowly spread in free-ranging deer and elk herds. That could change if CWD takes hold in the Midwest and the eastern United States. While deer and elk density in Colorado, Nebraska, Wyoming and South Dakota where CWD has been found is low, an average of about two animals per square mile, that density jumps to 20 to 30 deer per square mile in Ohio and Midwest states. In some urban areas around Cleveland, Chicago and major cities the deer density jumps as high as 90 animals per square mile.
"It's a whole different world with [CWD] east of the Mississippi with our high-density deer herds," John Buhnerkempe told the Chicago Sun-Times. Buhnerkempe is acting chief of Wildlife Resources for Illinois.
The Wisconsin deer infected with CWD were harvested near Mount Horeb, about 40 miles north of the Illinois border. Federal and state officers and landowners in the Mount Horeb area will shoot 500 white-tailed deer so they can be tested by Wisconsin officials for the deadly brain disease.
"The only way to test for CWD is to sample the brain stem," Reynolds said. "You can't test live deer for the disease."
First discovered in deer and elk in the northwest corner of Colorado, CWD is a relative of bovine spongiform encephalopathy, or mad cow disease. While similar to a disease of humans called Creutzfeld-Jacobs Disease (CJD), there is no evidence CWD can be transmitted to humans. [There is evidence that CWD prions can infect human brain tissue--BSE coordinator]
Wisconsin officials say there is no threat to cattle or sheep. The World Health Organization has monitored the CWD-infected area in Colorado and reports no scientific evidence that CWD is contagious to humans or cattle.
"We are just at the front end of evaluating the scope of the problem," said Julia Langenberg, a Wisconsin Department of Natural Resources veterinarian and administrator of the deer testing program.
The incidence of CWD is highest in captive herds of deer and elk. There are many deer and elk farms in Ohio, which raise the animals for human consumption. While the Ohio Division of Wildlife issues permits to allow deer and elk ranchers in Ohio to possess the animals the Ohio Department of Agriculture would have to issue guidelines for testing them for CWD and other diseases.
"We'll be working with the Ohio Department of Agriculture and may be seeking a ban on the importation of deer and elk to Ohio," Reynolds said. "We're most concerned about the captive deer and elk in Ohio."
The only testing that Ohio wildlife officials have done in recent years is for bovine tuberculosis.
"When tuberculosis was discovered in [free-ranging] deer in Michigan in the mid-1990s, we tested several hundred deer from northwestern Ohio for tuberculosis and other diseases," Reynolds said. "It is likely that we will begin a monitoring program starting with road-killed deer and deer harvested by hunters."
Michigan has already banned the importation of elk and deer from Wisconsin to protect both captive and wild deer and elk. There are more than 900 deer and elk operations in Michigan. The Michigan Department of Agriculture will also identify and trace all cervids, or deer and elk, which have been imported from Wisconsin over the past three years.
It is the first time Michigan has banned deer and elk imports from an entire state. Of 450 deer tested for CWD in Michigan, all have proven negative.
The spread of CWD became a high priority for Minnesota wildlife officials several months ago. Officials there plan to test wild deer killed by hunters next fall and is formulating a contingency plan if there is an outbreak of CWD.
This disease literally eats away at the brain of an infected animal and prevents the animal from converting food and body fat to energy. Animals become listless and begin to waste away. The disease is always fatal.
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