MARINETTE — The prevalence of Chronic Wasting Disease (CWD) in Wisconsin has been increasing every year since it was first discovered in the southern part of the state in 2001 and 2002 and that trend is likely to continue, Department of Natural Resources wildlife biologist Dave Halfmann told the Marinette County Development Committee on Tuesday.

“The first counties to find Chronic Wasting Disease were Dane and Iowa counties,” he said. “The prevalence rate of that is increasing every year at a pretty significant rate.

“In Iowa County, the prevalence is 50 percent in adult bucks, that’s very high. It should be a concern to everyone. The incidence is occurring across the entire state.”

Halfmann said only 16 of Wisconsin’s 72 counties have not been affected by CWD, explaining that affected means either having a wild or captive positive CWD deer in a county or within 10 miles of its boundary.”

“So this disease should be on everyone’s radar,” he said. “In Marinette County we’ve had two incidences of Chronic Wasting Disease.”

Halfmann said in June of 2018 within a captive deer farm in the northwest part of Marinette County, a deer tested positive for CWD and a surveillance zone was established from Goodman toward Armstrong Creek and Fence. In October of 2018, a wild adult doe in Dickinson County in the Upper Peninsula tested positive for CWD and a surveillance zone was established in the northeast part of nearby Marinette County from Pembine to Niagara.

“We’re trying to get 250 to 300 deer samples in the surveillance zones,” Halfmann explained. “That seems easy, but it can be very difficult to convince people to bring a deer head into us for disease  testing.

“Why 250 to 300?” he said. “That’s what we need based on what we model the population density to determine the disease to have a one-percent prevalence. The older (the deer) the better. The incidence of the disease increases with age.”

Halfmann said deer heads can be dropped off for testing either to kiosks, DNR staff or cooperators (individuals and businesses such as meat processors who assist with CWD sampling).

He presented a map of where the kiosks in the surveillance zones are located.

Committee member Mary Noll asked Halfmann how long it takes to get the results of testing for CWD?

“We have turned around samples early in the season in as soon as nine days,” he said. “Fourteen days on average.”

Supervisor Robert Holley asked what the long-range forecast is for CWD?

“It’s a disease currently that’s going to increase in prevalence,” Halfmann said. “We’ve seen that documented since 2001, particularly in the past five or six years. So the prevalence can be expected to increase and the spread is going to continue to occur because deer density is too high in many parts of the state.”

He said “there are not a lot of tools for good change coming.”

“We need public and legislative support to make changes that will continue to help slow the spread,” Halfmann said. 

He said proper handling and disposal of deer waste can help slow the spread of CWD.

“We haven’t double-fenced deer farms, that’s been an issue that has been lingering for a couple of years,” Halfmann said. “Deer spread the disease by close contact and that can happen through fences. 

“It can also happen between wild deer. The main thing that can slow this disease down is reducing the populations.”

Holley asked if there’s any legislation coming forward to reduce deer populations?

“Not that I’m aware of,” Halfmann said. “The DNR is continually working with county deer advisory councils. It just takes everyone in this state to get involved in deer management. We either have to come to acceptance of this disease or we have to limit these populations.”

He said the possibility of developing vaccines to stop the spread of the disease is being researched.

“There’s no practical application of a vaccine (to deer) at this time,” Halfmann said. “There’s a minor resistance within the deer population to the disease, but it’s very minor.”

Besides CWD, Halfmann said another major concern is the DNR is West Nile Virus.

“The West Nile Virus in grouse has been a concern in Wisconsin and Minnesota,” he said. “The department has worked with hunters to get grouse samples and tested those samples for the West Nike Virus. 

“It is a disease carried by mosquitoes. In some years the disease influences the deer population, as well as the wildlife population. Michigan felt it was having an impact on the grouse population so Wisconsin took up that effort to research what is going on.”

Halfmann said kits are available for hunters to take a sample of a grouse and send it to the DNR for testing.

“The sampling turned into such a big thing last year,” he said. “There were a lot of samples available and the labs are still working on testing. This is established as a three-year research project so the sampling of grouse is going to continue  this year.”

Halfmann said 2018 was a big year for the West Nile Virus, that it was found in cattle, humans, livestock, game birds and crows.

“This year across the state there have been very few reports (of the West Nile Virus),” he said. “How does  that make sense, you would think with all the rainfall this year that there’d be mosquitoes and illness all over. There’s not true for some reason, that’s what we’re trying to find out. Maybe something happened last year when we had cold stretches and lots of snow.”