Tick-borne relapsing fever (TBRF) is a bacterial infection transmitted by tick bite. The tick must be infected with the Borrelia spirochete to pass on the illness. Episodes of fever, or febrile periods, last approximately three days with seven days of afebrile periods in between.

The main symptom of TBRF is recurrent episodes of fever. However, fatigue, malaise, vomiting, abdominal pain, and other non-specific symptoms have also been reported. TBRF responds to penicillin, tetracyclines, and macrolides.