African tick bite fever (ATBF) is a vector-borne zoonosis caused by Rickettsia africae, an obligate intracellular gram-negative bacillus belonging to the spotted fever group of rickettsioses. It is common in travelers to southern African countries during the rainy season, in regions with tall grasses or abundant shade, and is the second most frequent cause of fever, after malaria, in travelers returning from sub-Saharan Africa. The bacterium is transmitted to humans primarily through the bite of hard ticks belonging to the Amblyomma genus, with Amblyomma hebraeum and Amblyomma variegatum being the principal vectors in sub-Saharan Africa.

Cattle, sheep, and other animals are the natural hosts, and humans are accidental hosts. Amblyomma ticks are aggressive and can bite people multiple times. ATBF occurs most frequently in individuals aged 18–64 years and shows a slightly higher incidence in males. Risk factors include outdoor exposure on safaris, game hunting trips, military exercises, field work, and participation in recreational sports. Dog owners who crush engorged ticks are also at risk for acquiring infection via conjunctival contamination (subsequently rubbing their eyes).

The disease is characterized by an acute influenza-like illness that develops 5-7 days after tick exposure. Common symptoms include myalgias, headache, fatigue, nightmares, and fevers. Neck pain and neck stiffness can also be prominent.

The febrile illness is often preceded by the formation of 1 or more eschars at the site(s) of tick bites. Regional lymphadenopathy is also a feature, and a widespread exanthematous or vesicular eruption occurs in about one-third of patients.

Systemic complications are rare but may include neuropsychiatric features, prolonged subacute neuropathy, and encephalopathy. Isolated cases of painful sacral syndrome, myocarditis, purpuric cellulitis, convalescent-phase asthenia, reactive arthritis, retinitis, and panuveitis have been described in untreated patients. Mortality is generally low with appropriate treatment.