Gulf War Deployments

Common Endemic Diseases
Tick-borne Typhus
(Mediterranean Spotted Fever)

Etiologic agents

• Rickettsia conorii

Clinical Features

• Onset is marked by high fever (39?C), severe headache, and frequently malaise, myalgia, arthalgia, or back pain.
• Patients who lack a tache noire (a small dark-centered ulcer that appears at the site of a tick bite) often have unilateral or bilateral conjunctivitis.
• Three to five days after onset, the patients typically presents with fever, a maculopapular rash and the tache noire.
• The disease is associated with significant weight loss.

Transmission

• A rickettsial disease introduced into the skin by the bite of the dog brown tick, skin excoriation (crushed tick) or through the conjunctiva.

Diagnosis

• The diagnosis should be suspected in a febrile patient with a history of a tick bite and/or the presence of a tache noire.
• Specific microimmunofluorescence (IFA) serological testing may confirm the diagnosis.

Prevention

• Prophylaxis is directed towards the prevention of tick bites. Removal of ticks within 20 hours of attachment reduces the probability of infection.

Additional Information

• The Merck Manual of Diagnosis and Therapy - Eastern Tick-Borne Rickettsioses

Back to Endemic Diseases List