The incidence of human babesiosis has been increasing in Wisconsin. This parasite, Babesia (Theileria) microti, is transmitted by the deer (blacklegged) tick. We find as many as 12% of the nymphs may be infected, depending on the location in Wisconsin. The human disease graph and maps on this page are from the Wisconsin Department of Health Services. Check out this link to find out more: https://www.dhs.wisconsin.gov/tick/babesiosis.htm