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Tick-borne Relapsing Fever

Tick-borne Relapsing Fever (TBRF) is a disease caused by Borrelia hermsii, a bacteria spread by Ornithodoros hermsi ticks in British Columbia (BC). In BC, there are 0 – 7 cases of TBRF each year.

Information for Health Professionals

B. hermsii are transmitted to humans through the bite of infected soft-bodied ticks of the genus Ornithodoros. These ticks usually live within rodent burrows, feeding on the rodent as it sleeps. Humans typically come into contact with Ornithodoros spp. ticks when they sleep in rodent-infested cabins, where ticks emerge to feed briefly on the person who is sleeping. Unlike hard-bodied ticks (e.g. Ixodes spp and Dermacentor spp), which can burrow into human skin for days, soft-bodied ticks feed quickly, usually lasting less than half an hour. Due to the short period of attachment to humans and typically during sleep, most people do not find a tick on themselves and may be unaware that they have been bitten. Transmission from mother to fetus is also known to occur.

Symptoms typically begin 3-12 days after exposure to an infected tick, and include: 
  • Periods of high fever (39oC to 43oC) lasting 1-3 days alternating with afebrile periods of 4-14 days, where the number of relapses can vary from 1-10 or more
  • Headache
  • Myalgia, arthralgia, shaking chills
  • Abdominal pain
Some people may experience more severe symptoms, including:
  • Bleeding problems
  • Neurological complications, such as confusion 
  • Inflammation in and around the heart
  • Respiratory failure
TBRF during pregnancy can cause:
  • Lower birth weights
  • Spontaneous abortion
  • Premature birth
  • Neonatal death
Diagnosis is made by different methods including:
  • Microscopic examination of a peripheral blood smear
  • Nucleic acid amplification test (NAAT)
  • Serology (blood) testing
  • Culture of Borrelia
Treatment with antibiotics is recommended. Awareness and avoidance are best to prevent this disease.

If TBRF is diagnosed or suspected, your doctor may prescribe antibiotics to ensure the best possible result.

Find more information about prevention of TBRF on the main tick-borne diseases page.

SOURCE: Tick-borne Relapsing Fever ( )
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