Minnesota's outbreak of chronic wasting disease (CWD) in wild deer appears to be spreading within the southeastern zone where it was first detected early last fall.
According to preliminary tests, seven new CWD cases are under investigation in Fillmore County. That's where 11 other whitetails were confirmed to be infected during surveillance that started during last year's hunting season.
Lou Cornicelli, wildlife research manager for Minnesota, said three of the new cases were detected in deer shot by hunters in Forestville-Mystery Cave State Park. That area is about 7 miles southwest of the main cluster of diseased deer shot by hunters and marksmen between Preston and Lanesboro.
"I don't know what it means yet," Cornicelli said.
He said the seven new cases showed up in a sample of 700 hunter-killed deer. That 1 percent infection rate is less alarming than the fact that three of the diseased deer were found in the state park, a fair distance away from the original cluster, Cornicelli said.
In Fillmore County's special disease management zone established last year by the Department of Natural Resources, CWD testing is mandatory for all whitetails taken by archery or firearms. Additional testing — not yet complete — will tell if the fatal animal disease has spread outside the special zone.
Craig Engwall, president of the Minnesota Deer Hunters Association, said the DNR informed him Tuesday of the new cases. "I'm going to check into it some more, but it's a downer," he said.
Until last year when the CWD outbreak was detected near Preston, Minnesota was said to be free of the disease in its wild herd of more than 1 million whitetails. The DNR hoped to stop the outbreak with an aggressive thinning of the deer herd in Fillmore County, backed up by comprehensive CWD testing of newly killed animals.
Because the outbreak originally was detected in a tight geographic cluster, it was believed to be in its early stages. Once the latest test results are in, the DNR will consider disease-management steps that may include expanded hunting to further thin the herd.
Jim Leach, director of the DNR's Fish and Wildlife Division, thanked southeastern Minnesota deer hunters for going along with CWD testing regimes and a ban on exporting deer from the area until test results are returned.
"Compliance was very high," Leach said.
The DNR also is testing for CWD in deer harvested by hunters in two special zones centered in Meeker and Crow Wing counties. The surveillance, which included mandatory testing of all deer taken on opening weekend of the firearms season, was set up around two deer farms that reported CWD in captive deer within the past year. So far, there have been no preliminary signs of CWD in wild deer in those areas, Cornicelli said.
According to the Centers for Disease Control and Prevention (CDC), no reported cases of CWD infection have shown up in people. However, the agency says animal studies suggest there may be a risk to people from eating meat from CWD-infected animals or coming in contact with brain or body fluids from infected animals.
Tony Kennedy • 612-673-4213
