Minnesota's leading authority on chronic wasting disease (CWD) wants deer hunters and landowners to fight harder against the disease despite signs that expanded hunting has chipped away at CWD's prevalence in Fillmore County.

"That's when you put the pressure on … not take it off,'' said Lou Cornicelli, wildlife research manager for the Department of Natural Resources (DNR).

In an interview this week, Cornicelli said the DNR has struggled recently to draw in good numbers of hunters and landowners to harvest more whitetails in the disease-management zone that includes rural Preston and the area around Forestville Mystery Cave State Park.

For two consecutive years, most of the county has been pounded by extra hunting and shooting to thin the local herd and stop the state's largest-ever outbreak of CWD, an always-fatal neurological disease in deer, elk and moose.

DNR's latest attempt to curb the outbreak targets 375 people who own private land around places where CWD was detected in wild deer. They've all been offered shooting permits, but only about 50 have signed up.

"How do we get more people to come along?'' Cornicelli said. "Folks aren't taking this as seriously as we are.''

Like last year, the Minnesota Deer Hunters Association is adding an incentive for participation. Anyone who takes a deer with a shooting permit this month or next month will be entered in a free drawing for a new muzzleloader rifle.

"We take CWD very seriously and we want to be active on the issues,'' said Craig Engwall, executive director of the Deer Hunters Association.

The shooting permits will be effective until mid-March. Only landowners or their designees can take deer. There is no public hunting opportunity. All deer will be sampled for CWD, including fawns.

Under a related deer-reduction plan last month, hunters harvested 374 whitetails in a special late-season hunt throughout Fillmore County. But that paled in comparison to the late-season hunt in January 2017 when 900 whitetails fell and were tested for CWD.

In all, DNR testing of deer harvested in Fillmore County since the fall of 2016 has identified 17 cases of CWD. Only six of those positives arrived last fall.

"We have acknowledged short-term reductions'' in prevalence of the disease, Cornicelli said.

But he said a greater herd reduction is needed to sustain the trend. The same strategy worked for the DNR in response to a previous outbreak of CWD in deer near Pine Island, Minn. In fact, the state's wild deer herd was thought to be free of CWD until the Fillmore County outbreak began in 2016.

Cornicelli said he wants Minnesota to stay aggressive in its campaign against the disease even though it's thoroughly established in nearby Iowa and Wisconsin. He said CWD-infected deer in advanced stages of the disease were seen in Wisconsin this year "staggering around.''

The central nervous system infections are caused by misshaped proteins known as prions. Infected animals shed the prions and scientists are still studying the human health implications. In areas where CWD is known to be present, the Centers for Disease Control and Prevention (CDC) recommends that hunters strongly consider having their big game tested before eating the meat.

Cornicelli said he knows some hunters are upset with the herd reduction in southeastern Minnesota. But it's the only workable strategy to keep disease-management zones from expanding and spilling over into new territories, he said.

Neil Mensink, an avid deer hunter who owns private land bordering Forestville Mystery Cave, said participation in the DNR's anti-CWD campaign has dwindled along with the herd. A lot of hunters don't believe the strategy will work, and they're unhappy that wildlife biologists haven't come up with an alternative.

"It's really hard for me to see all these deer get shot down,'' Mensink said. "It's been pretty devastating around here.''

Mensink said Fillmore County is now devoid of big bucks and that hunters especially frown on the late-season shooting permits because small bucks have shed their antlers and are mistaken for does.

In addition, shooting fawns is against the principles of many local hunters and fawns dominate the remaining deer population. "If I count 20 deer now, three-quarters are fawns,'' Mensink said.

Mark White, park manager at Forestville Mystery Cave, said he's heard from disgruntled deer hunters.

"I tell them there's no magic bullet on this and our people are just trying to do their best,'' White said. "We're trying to do something to battle the disease.''

White said there are no longer any deer to be found in the interior of the park. In the late-season hunt that ended last month, a lowly average of six deer per day were handled at the park's registration and CWD sampling station, he said. Far more deer were harvested in last year's late-season hunt, he said.