The Minnesota Department of Natural Resources (MN DNR) this week reported finding chronic wasting disease (CWD) only in deer in the southeastern corner of the state and not near recent captive-deer detections elsewhere, while Wisconsin officials today reported a newly affected county.
The Minnesota report comes after extensive sampling during the 2019 hunting season and special hunts in CWD-affected areas. Officials detected CWD in 27 wild deer, all in southeastern Minnesota, according to a Jan 21 MN DNR news release. The disease was not detected in central and north-central Minnesota, areas in which captive deer have tested positive.
"Overall, this is good news for Minnesota's wild deer," said Lou Cornicelli, PhD, MN DNR wildlife research manager. "The disease is still relatively rare across the state, and the CWD-positive test results this year came from areas where we had the most risk."
CWD is a deadly neurologic prion disease that affects cervids such as deer, elk, and moose. Though the disease has not yet jumped to humans, some experts fear it could mimic bovine spongiform encephalopathy ("mad cow" disease).
Officials tested 12,618 hunter-harvested deer in the southeastern CWD management and control zones, 3,965 in the north-central management zone, and 536 in the central surveillance area. They also sampled 282 deer found dead or reported sick, and 1 from the southeastern zone tested positive. Researchers are still submitting some samples from taxidermists, and the state DNR will post updated results on its website as they become available.
Of the 27 CWD-positive deer, 23 were from the fall hunting season and 3 from two special hunts after the regular hunting season. Officials found no CWD in deer from the southeast control zone, a buffer area around the management zone.
In all of 2018—not just during the hunting season—38 deer tested positive statewide, according to data on the MN DNR site.
New Wisconsin detections
Meanwhile, the Wisconsin DNR (WDNR) confirmed the first-ever detection of CWD in deer in Marathon County and the first CWD detection in Marquette County in more than a year, according to separate news releases today.
Marathon County is in the north-central part of the state, while Marquette County is in south-central Wisconsin.
The deer in Marathon County was harvested during the state's anterless hunting season in 2019 and was an adult. It was from an area within 10 miles of Shawano, Portage, and Waupaca counties.
State law requires that the WDNR enact a ban on baiting and feeding of deer in counties or portions of counties within a 10-mile radius of a deer that tests positive for CWD. Marathon, Shawano, Portage, and Waupaca counties are already identified as CWD-affected counties and already have baiting and feeding bans in place. The new detection will renew baiting and feeding bans in Marathon and Waupaca counties, while recent detections in a wild deer in Portage County and in a farm-raised deer in Shawano County renewed bans there.
Ryan Haffele, WDNR wildlife area supervisor said, "We have had a concerted effort to sample in this area since 2014 following the detection of CWD in a captive deer herd."
The CWD-positive deer in Marquette County was an adult doe and was harvested during the firearm season in 2019, which ran from Nov 23 to Dec 1. It is only the second deer in the county that tested positive for CWD, with the first occurring during the 2018 deer season. The finding renews baiting and feeding bans in Marquette, Green Lake, and Columbia counties.
Jan 21 MN DNR news release
Jan 23 WDNR news release on Marathon County
Jan 23 WDNR news release on Marquette County