The CDC has been tracking the Human Powassan Virus (POW) for the last decade.  While it is rare, some of the highest reported number of cases have been from Minnesota & Wisconsin.

People are infected with the virus from tick bites. The virus can cause the following symptoms according to the CDC:

Signs and symptoms of infection can include fever, headache, vomiting, weakness, confusion, seizures, and memory loss. Long-term neurologic problems may occur. There is no specific treatment, but people with severe POW virus illnesses often need to be hospitalized to receive respiratory support, intravenous fluids, or medications to reduce swelling in the brain.

In the last 10 years there have been 100 cases reported in the United States, and nearly half of those have come from Minnesota & Wisconsin.  MN had 25 cases reported since 2007.  Wisconsin has had 20 cases. The CDC has put together a incident map showing where the reports have come from in the last 10 years.

Even more concerning is many of the cases have come from Northern Minnesota.

The best way to prevent tick born illness is to wear long sleeves and pants when outdoors.  Also use tick repellent and check yourself after spending time outdoors in long grass or the woods.