DNR: CWD testing in ’20 shows low prevalence of disease in areas tested
Testing results from Minnesota’s 2020 hunting season and early 2021 special hunts confirmed chronic wasting disease in 22 wild deer, all within current disease management zones, according to the Minnesota DNR.
In total, 7,682 samples were tested from hunter-harvested deer or opportunistic samples (deer killed by vehicles, reported sick or found dead). Nineteen of the positives were from deer in the southeast management zone and three were from the south metro management zone.
CWD was not detected in the north-central disease management zone, the southeast control zone, or the surveillance areas put in place for the 2020 hunting season. The surveillance areas added in 2020 were in east-central and west-central Minnesota, as well as a south metro surveillance area that surrounds the south metro management zone.
“Though CWD is detected in Minnesota’s wild deer, our recent test results show that the disease prevalence remains relatively low,” said Erik Hildebrand, DNR wildlife health specialist. “Keeping deer healthy is our priority, and we continue to take aggressive action in areas where the disease has been detected in wild deer and monitor for the disease in areas where there are elevated risks for CWD.”
Some test results from the year’s management activities and any deer reported sick or dead are still pending; results will be updated as they become available.
The DNR monitors CWD by testing wild deer. When the disease is detected in either captive or wild deer, the DNR establishes surveillance areas and tests wild deer for at least three years after the detection. This is because it can take 1 ½ to 3 years before a deer shows clinical symptoms. If three consecutive years of test results fail to confirm CWD, and an adequate number of deer are sampled, the DNR will end surveillance in an area.
In fall 2020, the DNR shifted to voluntary self-service sampling to facilitate social-distancing measures at sampling stations during the COVID-19 pandemic. With the shift, the DNR set sampling goals that would allow the agency to confidently assess disease prevalence in an area. While the majority of areas received enough samples to meet sampling goals, some surveillance areas did not.
The DNR will continue sampling for disease in these areas to enhance confidence about disease detection.
“We appreciate all those who participated in sampling this year. Each deer tested gives valuable information that contributes to our understanding of the disease’s prevalence and geographic distribution in our herd,” Hildebrand said.