UMEM Educational Pearls

Category: International EM

Title: Relapsing Fever

Keywords: international, fever, Borrelia, tick, louse (PubMed Search)

Posted: 10/24/2012 by Andrea Tenner, MD (Updated: 4/22/2024)
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  • Causative organism: members of the genus Borrelia
    • Louse Borne Relapsing Fever (LBRF)
      • Human body louse (Pediculus humanus)
      • Associated with sporadic outbreaks especially in areas with large refugee populations
    • Tick Borne Relapsing Fever (TBRF)
      • Soft ticks of the genus Ornithodoros
      • Typically found in higher elevations of the western United States as well as the central plateau region of Mexico, Central and South America and Africa
  • Clinical Presentation
    • Symptoms develop 3 to 18 days after infection.
    • Onset is abrupt and may include fever, malaise, headache, arthralgias, nausea and vomiting and cough.
    • The first febrile episode lasts 3 to 6 days and then recurrences may occur after 7 to 10 days.
  • Diagnosis
    • Definitive diagnosis: visualization of spirochetes on peripheral blood smear.
    • May also see leukocytosis, anemia and/or thrombocytopenia, elevation of liver function tests
    • Erythrocyte rosette formation may be present.
  • Treatment
    • Antibiotics recommended for treatment include penicillin, doxycycline and erythromycin.
    • Jarisch-Herxheimer reaction common after treatment. This can be life threatening and all patients undergoing treatment should be closely monitored.

University of Maryland Section for Global Emergency Health

Author: Gentry Wilkerson


  1. Centers for Disease Control and Prevention CDC. Tickborne relapsing fever in a mother and newborn child--Colorado, 2011. MMWR Morb Mortal Wkly Rep. 2012;61(10):174–176.
  2. Larsson C, Andersson M, Bergström S. Current issues in relapsing fever. Curr Opin Infect Dis. 2009;22(5):443–449.