MINNEAPOLIS (WCCO) — The Minnesota Department of Natural Resources says a disease that has killed millions of bats in North America has been confirmed in six Minnesota counties.

White-nose syndrome (WNS), which can be fatal to hibernating bats, was recently confirmed in Becker, Dakota, Fillmore, Goodhue and Washington counties. Last March, it was confirmed in St. Louis County.

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The DNR says in locations where WNS is confirmed, bat populations have decreased anywhere from 31 to 73 percent.

“While some locations are still testing negative, the results of recent surveys lead us to conclude that WNS is likely to be present anywhere bats hibernate in Minnesota,” said Ed Quinn, DNR natural resource program supervisor. “Four of Minnesota’s bat species hibernate, and four species migrate. WNS will have a substantial effect on Minnesota’s hibernating bat population. Neighboring states have reported declines of 70 to 95 percent in specific locations, as we recorded this year at Soudan Mine.”

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The disease is named after the white fungal growth that can be seen on infected bats. It is not known to pose a threat to humans, pets, livestock or other wildlife.

According to the DNR, the disease is mostly transmitted from bat to bat, but humans can inadvertently bring fungal spores into other caves via their clothing and caving gear.

Now, the DNR is working with federal and state officials to consider a variety of treatment trails to test if new fungicides can help kill WNS spores. While the treatments are unlikely to end WNS, it could slow the spread of the disease and reduce the number of bat deaths.

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The DNR says WNS was first discovered in 2007 in eastern New York and has since spread to 30 states and five Canadian provinces – killing more than 5.7 million bats.