African tick bite fever (ATBF) is a bacterial infection spread by the bite of a tick. Symptoms may include fever, headache, muscle pain, and a rash. At the site of the bite there is typically a red skin sore with a dark center. The onset of symptoms usually occurs 4–10 days after the bite. Complications are rare but may include joint inflammation. Some people do not develop symptoms.Tick bite fever is caused by the bacterium Rickettsia africae. The bacterium is spread by ticks of the Amblyomma type. These generally live in tall grass or bush rather than in cities. The diagnosis is typically based on symptoms. It can be confirmed by culture, PCR, or immunofluorescence.There is no vaccine. Prevention is by avoiding tick bites by covering the skin, using DEET, or using permethrin treated clothing. Evidence regarding treatment, however, is limited. The antibiotic doxycycline appears useful. Chloramphenicol or azithromycin may also be used. The disease will also tend to resolve without treatment.The disease occurs in sub-Saharan Africa, the West Indies, and Oceania. It is relatively common among travelers to sub-Saharan Africa. Most infections occur between November and April. Outbreaks of the disease may occur. The earliest descriptions of the condition are believed to be from 1911. African tick bite fever is a type of spotted fever. It has previously been confused with Mediterranean spotted fever. Signs and symptoms
African tick bite fever is often asymptomatic or mild in clinical presentation and complications are rare.
The onset of illness is typically 5–7 days after the tick bite, although in some cases it may take up to 10 days for symptoms to occur. Symptoms can persist for several days to up to three weeks. Common presenting symptoms include:

Fever
Headache
Muscle aches
Inoculation eschar, which is dead, often black, tissue around a bite site (see photo above)
Eschars may or may not be present. Amblyomma ticks actively attack cattle or humans and can bite more than once. In African tick bite fever, unlike what is typically seen with other Rickettsial spotted fevers when only one eschar is identified, multiple eschars may be seen and are considered pathognomonic. Swollen lymph nodes near the site of the bite
Maculopapular and/or vesicular rash

Complications
Complications are rare and are not life-threatening. No deaths due to African tick bite fever have been reported. Reported complications include:

Prolonged fever > 3 weeks in duration
Reactive arthritis
Moderate to severe headache

Cause
Bacteriology
Rickettsia africae is a gram-negative, obligate intracellular, pleomorphic bacterium. It belongs to the genus Rickettsia, which includes many bacterial species that are transmitted to humans by arthropods. Vectors
Two species of hard ticks, Amblyoma variegatum and Amblyomma hebraeum are the most common vectors of R. africae. Typically, Amblyomma hebraeum transmits the bacteria in South Africa while Amblyoma variegatum carries R. africae throughout West, Central and East Africa and through the French West Indies. Other species of Amblyomma in sub-Saharan Africa can also transmit R. africae and it may be that up to 100% of Amblyomma ticks in sub-Saharan Africa carry R. africae.