Surveillance of spotted fever rickettsioses at Army installations in the U.S. Central and Atlantic regions, 2012-2018.

Spotted fever rickettsioses (SFR) are emerging in the Atlantic and Central regions of the U.S., though cases have been reported across the contiguous U.S. Military populations may be at increased risk for SFR because of residence in these regions and frequent field training in tick habitats. Surveillance for Rocky Mountain spotted fever in the Army began in 1998 and was expanded to include all SFR in 2017. Between 2016 and 2017, the rate of active component cases reported from Army installations in the Atlantic and Central regions of the U.S. increased nearly five-fold from 2016 (0.55 per 100,000 person-years [p-yrs]) to 2017 (2.65 per 100,000 p-yrs). The majority of SFR cases were reported from Fort Leonard Wood, MO, and Fort Bragg, NC. Most reported cases had no documented symptoms consistent with SFR and could not be confirmed as "cases" by standard case-defining methods. SFR surveillance and control efforts in military populations can be improved by better adherence to guidelines for SFR diagnosis and through the use of available advanced laboratory techniques.