African tick bite fever

African Tick Bite Fever

African tick bite fever is an infectious disease caused by the bacterium Rickettsia africae. It is transmitted to humans through the bite of infected ticks, primarily of the Amblyomma genus. This disease is part of the spotted fever group of rickettsial infections.

Etiology

The causative agent of African tick bite fever is Rickettsia africae, a gram-negative, obligate intracellular bacterium. It is transmitted by ticks of the Amblyomma genus, particularly Amblyomma variegatum and Amblyomma hebraeum.

Epidemiology

African tick bite fever is endemic in sub-Saharan Africa and the Caribbean. It is considered a common travel-associated infection for individuals visiting rural areas in these regions. The disease is often reported in travelers returning from safaris or hiking trips.

Clinical Presentation

The incubation period for African tick bite fever is typically 5 to 7 days. The disease is characterized by the sudden onset of fever, headache, muscle pain, and a distinctive skin rash. A key feature is the presence of an eschar at the site of the tick bite, which is a necrotic lesion surrounded by a red halo.

Leg lesion caused by African tick bite fever

Diagnosis

Diagnosis of African tick bite fever is primarily clinical, based on the presence of fever, rash, and eschar in a patient with a history of tick exposure in endemic areas. Laboratory confirmation can be achieved through serological tests or polymerase chain reaction (PCR) assays to detect Rickettsia africae DNA.

Treatment

The treatment of choice for African tick bite fever is doxycycline, an antibiotic effective against rickettsial infections. Treatment typically leads to rapid resolution of symptoms.

Prevention

Preventive measures include avoiding tick-infested areas, using insect repellents, wearing protective clothing, and performing regular tick checks after potential exposure. Travelers to endemic regions should be educated about the risks and preventive strategies.

Related Pages

• Rickettsial infection
• Amblyomma
• Eschar
• Doxycycline

Gallery

• 
  Amblyomma variegatum male
• 
  Amblyomma hebraeum

• 
  Leg lesion caused by African tick bite fever
• 
  Male Amblyomma variegatum tick
• 
  Amblyomma hebraeum tick