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Tickborne Diseases of the United States


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Tickborne Relapsing Fever (TBRF)(Soft Tick Relapsing Fever)					minus icon
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			HomeTick IDOverview of Tickborne DiseasesLyme DiseaseTickborne Relapsing Fever (TBRF)Hard Tick Relapsing FeverAnaplasmosisEhrlichiosisRocky Mountain Spotted FeverRickettsia parkeri RickettsiosisTularemiaBabesiosisHeartland and Bourbon Virus DiseasesColorado Tick FeverPowassan Virus DiseaseTickborne Diseases AbroadTick Bites/PreventionLyme Disease Prophylaxis After Tick Bite					Related Pages
										Agent*Borrelia hermsii, B. turicatae*Where FoundIn the United States, TBRF usually occurs in mountainous areas of Western states, where it is associated with exposure to soft ticks in rustic cabins (*B. hermsii*), and in Texas, where it is most often associated with exposure to soft ticks in caves (*B. turicatae*).Incubation PeriodApproximately 7 days (range 4-21), with recurrent febrile episodes that last around 3 days and are separated by afebrile periods of approximately 7 days.Signs and SymptomsTBRF most commonly presents with fever, headache, and myalgias. As with other borrelioses, neurologic involvement is possible, including meningoencephalitis, cranial neuritis and ocular manifestations. Acute respiratory distress syndrome is a rare complication.
High fever with relapses
Chills/rigors
Sweats
Headache
Myalgia/arthralgia
Dizziness
Nausea/vomiting
Facial palsy (rarely)**Note:** TBRF can be transmitted transplacentally and has been associated with pregnancy complications including spontaneous abortion, premature birth, and neonatal death.General Laboratory FindingsLeukocytosis
Thrombocytopenia
Mild hyperbilirubinemia
Elevated erythrocyte sedimentation rate
Slightly prolonged prothrombin time (PT) and partial thromboplastin time (PTT)Laboratory DiagnosisTests may include the following:
Visualization of spirochetes by microscopy of peripheral blood obtained during a febrile episode prior to treatment.
Molecular testing, such as PCR. Molecular tests should be performed as early as possible, ideally prior to treatment or soon after. PCR testing is more sensitive than microscopy.
Serologic testing by immunofluorescence assay (IFA), enzyme immunoassay (EIA), or immunoblot.**NOTE:** Serologic tests and some commercially available PCR tests cross-react with other *Borrelia* species, including *B. burgdorferi,*the cause of Lyme disease.TreatmentTreatment data for patients with TBRF are limited. Consider the following regimens for nonpregnant patients who do not have neurologic complications. In pregnant individuals or when neurologic involvement is present, initial parenteral therapy with a beta-lactam is advised; treatment should be continued for 10-14 days with close monitoring given the potential for severe complications.
TFRF Treatment regimens
Age category
Drug
Dosage
Duration (days)Adults
Doxycycline, oral or intravenous (first-line)
100 mg every 12 hours
10Azithromycin, oral
500 mg daily
10Penicillin G, intravenous
4,000,000 units every 6 hours
10Ceftriaxone, intravenous
2 g daily
10Children
Doxycycline, oral or intravenous (first-line)
2.2 mg/kg per dose, every 12 hours, maximum 100 mg/dose
10Azithromycin, oral
10 mg/kg daily, maximum 500 mg/day
10Penicillin G, intravenous
50,000-100,000 units/kg every 6 hours, maximum 4,000,000 units/dose
10Ceftriaxone, intravenous
50-75 mg/kg daily, maximum 2 g/day
10**NOTE:** When initiating antibiotic therapy, all patients should be observed during the first 4 hours of treatment for a Jarisch-Herxheimer reaction.See www.cdc.gov/relapsing-fever/clinicians for detailed treatment information.ReferencesCenters for Disease Control and Prevention. Acute respiratory distress syndrome in persons with tickborne relapsing fever—Three states, 2004–2005. *MMWR Morb Mortal Wkly Rep.* 2007;56(41): 1073–1076.
Centers for Disease Control and Prevention. Tickborne relapsing fever—United States, 1990–2011. *MMWR Morb Mortal Wkly Rep.* 2015;64(3):58-60.
Dworkin MS, Anderson DE Jr, Schwan TG, et al. Tick-borne relapsing fever in the northwestern United States and southwestern Canada. *Clin Infect Dis.* 1998;26(1):122-31.
Hashavya S, Gross I, Gross M, et al. Tickborne Relapsing Fever, Jerusalem, Israel, 2004-2018. *Emerg Infect Dis*. 2020;26(10):2420-2423.
Lyme Disease and Other Nonsyphilitic Spirochetal Infections. In: Jameson J, Fauci AS, Kasper DL, Hauser SL, Longo DL, Loscalzo J. eds. Harrison’s Manual of Medicine, 20e. McGraw Hill; 2020.
Yagupsky P, Moses S. Neonatal *Borrelia* species infection (relapsing fever). *Am J Dis Child*. 1985 Jan;139(1):74-6.Top of Page
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						Page last reviewed:  August 5, 2022					Content source: 	Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Vector-Borne Diseases (DVBD) homeTickborne Diseases of the United StatesTick IDOverview of Tickborne DiseasesLyme DiseaseTickborne Relapsing Fever (TBRF)Hard Tick Relapsing FeverAnaplasmosisEhrlichiosisRocky Mountain Spotted Fever*Rickettsia parkeri*RickettsiosisTularemiaBabesiosisHeartland and Bourbon Virus DiseasesColorado Tick FeverPowassan Virus DiseaseTickborne Diseases AbroadTick Bites/PreventionLyme Disease Prophylaxis After Tick Bite


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