From the Guidelines
Mediterranean spotted fever is caused by the bacterium Rickettsia conorii, which is transmitted to humans through the bite of infected ticks, primarily the brown dog tick (Rhipicephalus sanguineus).
Cause and Transmission
The disease is endemic in the Mediterranean basin, Middle East, parts of Africa, and the Indian subcontinent 1.
- The brown dog tick (Rhipicephalus sanguineus) is the principal tick vector in Europe, Israel, and North Africa.
- Dogs can serve as reservoir hosts for R. conorii, and infected Rh. sanguineus ticks can transfer from dogs to humans during interactions.
Treatment
Treatment consists of antibiotic therapy with doxycycline as the first-line medication, typically prescribed at 100 mg twice daily for adults for 7-14 days depending on clinical response 1.
- For children under 8 years old, doxycycline can still be used for short courses (5 mg/kg/day divided into two doses), despite traditional concerns about dental staining.
- Alternative antibiotics include chloramphenicol (50-75 mg/kg/day divided into four doses) or fluoroquinolones like ciprofloxacin (500 mg twice daily) for adults with doxycycline contraindications.
- Treatment should begin immediately upon clinical suspicion without waiting for laboratory confirmation, as early intervention significantly reduces complications and mortality.
Clinical Presentation and Prevention
The disease typically presents with fever, headache, muscle pain, and a characteristic rash, often accompanied by a black eschar ("tache noire") at the tick bite site.
- Prevention involves avoiding tick-infested areas, using insect repellents, wearing protective clothing, and promptly removing attached ticks.
- The incubation period is typically 5–7 days but can be up to 10 days after the bite of an infected tick 1.
From the FDA Drug Label
Doxycycline is indicated for the treatment of the following infections: Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever, rickettsialpox, and tick fevers caused by Rickettsiae.
- Cause of Mediterranean spotted fever: The FDA drug label does not explicitly mention Mediterranean spotted fever, but it is known to be caused by Rickettsia conorii, which is a type of Rickettsiae.
- Treatment of Mediterranean spotted fever: Based on the drug label, doxycycline is indicated for the treatment of infections caused by Rickettsiae, which includes the causative agent of Mediterranean spotted fever 2.
From the Research
Cause of Mediterranean Spotted Fever
- Mediterranean spotted fever is caused by Rickettsia conorii conorii, a bacterium transmitted to humans by the brown dog tick Rhipicephalus sanguineus 3, 4, 5, 6.
- The disease is characterized by a symptomatologic triad: fever, exanthema, and "tache noire", the typical eschar at the site of the tick bite 3.
Transmission and Epidemiology
- The brown dog tick Rhipicephalus sanguineus is the primary vector of Rickettsia conorii conorii, and the disease is endemic in the Mediterranean basin 3, 4.
- The seasonal peak of the disease occurs during the maximal activity of immature stage ticks, from June to September 3.
- Severe forms of the disease have been reported in 6% of patients, especially adults with underlying conditions such as diabetes, cardiac disease, and chronic alcoholism 3.
Treatment of Mediterranean Spotted Fever
- The standard treatment for Mediterranean spotted fever is oral or parenteral administration of tetracyclines or chloramphenicol 3.
- Doxycycline is the treatment of choice, and it has been shown to protect patients from developing severe MSF and induce earlier defervescence compared to other treatment regimens 7.
- Fluoroquinolone treatment is not recommended, as it has been associated with increased disease severity and longer hospital stays 7.
- Alternative treatments, such as oral clarithromycin and azithromycin, may be acceptable for the treatment of the disease in children and during pregnancy 3.