Probable African Tick Bite Fever in the United States

African tick bite fever (ATBF) is a tick-borne rickettsial disease most often observed in North American and European tourists returning home from the southern portion of Africa. Ticks infected with Rickettsia africae transmit this parasitic bacterium to humans, who subsequently develop an influenza-like illness, one or more inoculation eschars, and in some cases, a cutaneous rash. Because ATBF often presents with non-specific symptoms that suggest other infectious diseases, establishing the diagnosis may be difficult. Confirmatory assays, including serology and nucleic acid amplification, may take weeks to return and cannot help with acute treatment decisions. We present a case of a previously healthy 60-year-old woman who developed an illness strongly suggestive of ATBF after a missionary trip to Zimbabwe and discuss the disease’s diagnostic challenges. Our paper also reviews the epidemiology of this disease and the currently available diagnostic laboratory tests and recommended treatment options.