tick-bourne relapsing fever

Etiology

• most cases caused by Borrelia hermsii

Clinical manifestations

• fever for 3-5 days
• recurrent fever about a week after apparent recovery

Laboratory

• spirchetes in blood smear taken during a febrile episode stained with Wright-Giemsa stain or examined with dark field microscopy
• Borrelia hermsii antibody in serum
  • not useful in during initial febrile episode
  • may be useful after recurrence of fever
• Borrelia hermsii culture

Management

• when initiating antibiotic therapy, all patients should be observed during the first 4 hours of treatment for a Jarisch-Herxheimer reaction
• tetracycline 500 mg every 6 hours for 10 days
• 500 mg (or 12.5 mg/kg) every 6 hours for 10 days (alternative)
• ceftriaxone 2 grams IV/IM QD for 10-14 days for patients with central nervous system involvement

More general terms

• relapsing fever
• tick borne infection