Health and Human Services Agency

Margaret Williams

(530) 642-7164




(Placerville, CA) – El Dorado County Public Health is reminding residents and visitors to use precautions to prevent Tick-borne Relapsing Fever, after receiving reports of two cases of the illness in the past two months. "Both cases of Tick-borne Relapsing Fever were reported in individuals who had stayed in cabins in the greater Tahoe area," said Heather Orchard, Supervising Public Health Nurse with Public Health. "The individuals who became ill have since received treatment and recovered. The illness can be prevented by keeping rodents out of dwellings, not sleeping in any building where there is obvious rodent infestation and taking a few other basic precautions."

Tick-borne Relapsing Fever (TBRF) is a bacterial infection that can cause recurring bouts of fever, headache, muscle and joint aches, and nausea. The bacteria are carried by soft ticks that feed on rodents such as squirrels, chipmunks, and mice. The ticks usually live in the nests of the rodents.

Rodents may sometimes build nests in the walls, attics, or other void spaces of cabins, houses, or other buildings. The ticks that carry TBRF may leave those nests if the rodents have left or have been removed, and may seek out other mammals upon which to feed, including humans. The bite of a soft tick is painless and they attach to feed for only a few minutes. Soft ticks often feed at night; so many people are bitten while asleep and never realize it.

People can get TBRF when they are bitten by an infected soft tick. Most people are infected while visiting rural mountain areas, typically between 3,000 and 9,000 feet during the summer months. TBRF is not transmitted from person-to-person.

According to Orchard, persons with TBRF may develop a sudden high fever (104-105 F), chills, headache, and muscle ache about a week after being bitten by an infected tick. They may also have nausea, vomiting, abdominal pain, and a rash. These symptoms last 3-5 days and then quickly disappear. A few days later, the fever and other symptoms occur again ("relapse"). This cycle may continue for several weeks if not treated. "If you develop these symptoms you should see your doctor right away. TBRF is treated with antibiotics," said Orchard.

TBRF is endemic in many areas of California, particularly mountainous areas, and is typically associated with rustic cabins. The following precautions are advised to prevent TBRF:

  • Keep rodents out of dwellings.
  • Remove rodent nesting materials such as newspapers, wood piles, and other accumulated debris from in and around home.
  • Store all food in well-sealed containers.


In addition to the above precautions, if staying in a mountain cabin, condominium, or other dwelling:

  • Inspect the inside and outside of the building for evidence of rodents (holes or gnaw marks in the walls, droppings, and/or nests).
  • Avoid sleeping on the floor or on a bed that touches a wall.
  • Change and wash all bedding before use.


For more information about TBRF visit:


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