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With deer hunting season winding to a close, Minnesota wildlife researchers are somewhat encouraged that a huge increase in testing for chronic wasting disease (CWD) in hunter-harvested deer resulted in only 12 new detections as of Friday.

The positive test results all came from the southeast CWD management zone where hunters cooperated to give the Department of Natural Resources more than 11,000 tissue samples from as many deer. That’s a 144 % increase in test samples from the previous hunting season, when 15 hunter-harvested deer were found to be infected with the fatal brain-wasting disease.

DNR Wildlife Health Group Leader Michelle Carstensen said she was pleased with the preliminary results but was still analyzing them. This season’s testing program for hunter-harvested deer covered a lot more territory and sampled every deer that was more than 1 year old. Researchers found less infection in the region’s “CWD Core’’ area between Preston and Lanesboro than in previous years.

Southeastern Minnesota deer hunter Jeremy Schmit, secretary for Bluffland Whitetails Association, said the addition of 12 positive CWD test results throughout the hunting season is a good sign.

“We’re not seeing an explosion of new cases,’’ he said.

Schmit said more hunters in the region are seeing value in the DNR’s strategy to thin the region’s deer population with extra hunting, test all deer for the disease and emphasize safe carcass handling to prevent the spread of infectious prions shed by diseased deer — dead or alive.

This season’s testing confirmed a suspected hot spot of CWD around a defunct Winona County deer farm that was 100% infected with CWD when it was shut down early in 2018. The farm was poorly fenced and had unreported escapes of deer into the wild, state officials have said.

Six cases of CWD are now confirmed in wild deer killed near the farm, including three harvested this fall by hunters. Meanwhile, a small cluster of CWD-positive test results emerged this hunting season in Houston County. Carstensen said the DNR is investigating.

Outside of southeastern Minnesota, the DNR this hunting season actively tested hunter-harvested deer around two defunct deer farms north of the Twin Cities where CWD was detected starting in 2016. Zero positives were found among 532 deer tested this fall in Meeker County, and zero positives were found among the first 3,500 test results in Crow Wing County.

A relatively small number of test results were still pending for all areas as of Friday.

Minnesota’s only large-scale outbreak of CWD in wild deer showed up during the 2016 firearms hunting season in Fillmore County. Since then, 60 more diseased deer have been detected throughout the Driftless Region and one more tested positive early last year in Crow Wing County.