Anaplasmosis: Wisconsin Data

Anaplasmosis is the second most common illness spread by ticks in Wisconsin, after Lyme disease.

From 2016 through 2025, Wisconsin had an average of 617 confirmed and probable cases of anaplasmosis reported per year.

In 2025, a total of 1076 confirmed and probable cases of anaplasmosis were reported, the highest ever documented in Wisconsin.

Cases are most commonly reported among people living in the northern, western, and northeastern regions of the state.

Anaplasmosis is preventable and treatable. Learn more about Tick Bite Prevention.

Read about Treatment and Signs and Symptoms from the CDC (Centers for Disease Control and Prevention).

The map and graphs on this page show statewide data for anaplasmosis.

For national data, visit the CDC webpage on Anaplasmosis Epidemiology and Statistics.