Spotted Fever Group Rickettsiosis: Wisconsin Data

Commonly available tests to diagnose spotted fever group rickettsioses (SFGR) cannot distinguish between the different spotted fever group bacteria. Therefore, cases of Rocky Mountain spotted fever (RMSF) and all other diseases caused by this group of bacteria are all reported as SFGR. It is unknown how many reported cases in Wisconsin are RMSF, and how many cases are due to other, less severe, SFGR.

SFGR cases are reported by county of residence, not by county of exposure. On average, half of SFGR cases in Wisconsin were among people who reported travel to another U.S. state where SFGR is much more common prior to becoming sick. This means that some of the SFGR cases in Wisconsin were most likely acquired outside of Wisconsin.

The first case of SFGR in Wisconsin was identified in 2009. In 2020, Wisconsin had three probable cases of SFGR. SFGR is preventable and treatable.

Below are the statewide data for SFGR. For information on national data, including a map detailing cases in the United States, visit the Centers for Disease Control and Prevention (CDC) Statistics and Epidemiology page.

Map of Spotted Fever Group Rickettsiosis by County in Wisconsin


SFGR Cases in Wisconsin

Total Spotted Fever Group Rickettsiosis Cases in Wisconsin

Cases Reported by Month and Age

Month of illness onset

Spotted Fever Group Rickettsiosis Cases by month

Age group

Spotted Fever Group Rickettsiosis Cases by age

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Last Revised: September 21, 2022