A mule deer shot by a hunter last fall in southwestern North Dakota has tested positive for chronic wasting disease, the first time the fatal brain disease has been detected in North Dakota.

That means that CWD has been found in wild deer in three of the four states bordering Minnesota. Only Iowa is CWD-free. Wild deer in Wisconsin and South Dakota also have been found with the disease. Despite testing of more than 30,000 deer in recent years in Minnesota, the disease hasn't been found in the wild here.

And state officials are desperately hoping to keep CWD from infecting the wild deer herd. The Minnesota DNR has increased deer testing in the border area with Wisconsin, and plans to do more testing next fall. The North Dakota discovery -- because it occurred in the western part of the state far from the Minnesota border -- won't have an immediate impact on Minnesota's actions, said Lou Cornicell, DNR big game program manager.

In North Dakota, a sick-looking adult mule deer was taken in western Sioux County. It was tested for both CWD and bovine tuberculosis.

The North Dakota Game and Fish Department's targeted surveillance program is an ongoing, year-round effort that tests animals found dead or sick. In addition, the department annually collects samples taken from hunter-harvested deer in specific regions of the state. In January, more than 3,000 targeted and hunter-harvested samples were sent to a lab in Minnesota. As of Wednesday, about two-thirds of the samples have been tested, with the one positive. The remaining one-third will be tested over the next month.

CWD affects the nervous system of members of the deer family and is always fatal. Scientists have found no evidence that it can be transmitted naturally to humans or livestock.