A recent study done by Michigan State University is reacting to that by focusing on white-tailed deer, a core host for black-legged ticks (deer ticks). The number of deer ticks is slowly increasing here in the state of Michigan. Tick Spread and Disease Trends in MichiganLyme disease cases have jumped up by 168% from 2020 to 2024, from 452 cases to over 1,200 cases. Anaplasmosis, another disease carried by black-legged ticks, has surged almost fivefold in the same period of time. Officials have detected black-legged ticks in all 83 Michigan counties now.