Tick-Borne Relapsing Fever (TBRF) fact sheet

• Tick-borne relapsing fever (TBRF) is a disease caused by bacteria called Borrelia. The bacteria are spread by soft (argasid) ticks that are infected with the bacteria from feeding on infected wild rodents such as squirrels, chipmunks and mice.
• TBRF occurs worldwide where argasid ticks are present. The disease is uncommon in the United States, but cases do occur in western states with fewer than 10 reported cases annually in Washington State.
• In the Western United States and British Columbia, soft ticks may live in rodent-infested buildings or cabins located in rural, wooded or mountainous areas at 1,500 to 8,000 feet elevation.

Symptoms usually develop within 7 days (with a range of 2 to 18 days) after a bite by an infected tick.

• Symptoms may include:
  • Sudden high fever with chills and sweats
  • Headache and body aches
  • Nausea, loss of appetite and vomiting
  • Rash
  • Sensitivity to bright light
  • Dizziness and confusion
• TBRF is characterized by relapsing (recurrent) periods of fever and other symptoms. Symptoms last for 2 to 7 days, disappear for about 4 to 14 days, and then recur. This cycle may go on for weeks if treatment is not started.

• People get infected when they are bitten by infected, soft ticks. These ticks prefer to bite rodents, but will bite humans if rodents are scarce.
• Most people do not notice a bite by a soft tick because 1) the bite is often painless, 2) the ticks are attached for less than 30 minutes, and 3) the ticks feed at night.
• Infection in humans often occurs after rodent extermination or die-offs without simultaneous tick fumigation.
• TBRF is not spread from person to person, except in pregnant women who may sometimes spread the infection to the fetus.

• Be aware of potential exposures to ticks when camping in wooded areas in the mountains.
• Use insect repellant containing DEET on skin or clothing and wear long sleeve shirts and long pants in areas with ticks. Permethrin-treated clothing offers additional protection. Treatment kits or pre-treated clothing are available at some outdoor recreation stores.
• Check sleeping areas in cabins for evidence of rodents. If the dwelling has been unoccupied, change and wash all bedding before use. Avoid sleeping on the floor and move beds away from walls to limit the possibility of contact with ticks.
• Rodent-proof buildings and remove rodent nesting materials from walls, ceiling, and floors.
• Information on rat prevention and how to clean up around rats
• After removing rodents, fumigate buildings to eliminate ticks. More than one treatment is often needed. Always follow product instructions and consider contacting a licensed pest control specialist.
  
• For more information on TBRF, see: www.cdc.gov/ncidod/dvbid/RelapsingFever