Relapsing fever is a bacterial infection transmitted by a louse or tick. It is characterized by repeated episodes of fever.
Tick-borne relapsing fever; Louse-borne relapsing fever
Relapsing fever is an infection caused by several species of bacteria in the borrelia family.
There are two major forms of relapsing fever:
Sudden fever occurs within 2 weeks of infection.
In both forms, the fever episode may end in "crisis." This consists of shaking chills, followed by intense sweating, falling body temperature, and low blood pressure. This stage may result in death.
In the United States, TBRF often occurs west of the Mississippi River, particularly in the mountains of the West and the high deserts and plains of the Southwest. In the mountains of California, Utah, Arizona, New Mexico, Colorado, Oregon, and Washington, infections are usually caused by Borrelia hermsii and are often picked up in cabins in forests. The risk may now extend into the southeastern United States.
LBRF is mainly a disease of the developing world. It is currently seen in Ethiopia and Sudan. Famine, war, and the movement of refugee groups often results in LBRF epidemics.
Symptoms of relapsing fever include:
Exams and Tests
Relapsing fever should be suspected if someone coming from a high-risk area has repeated episodes of fever. This is largely true if the fever is followed by a "crisis" stage, and if the person may have been exposed to lice or soft-bodied ticks.
Tests that may be done include:
Antibiotics including penicillin and tetracycline are used to treat this condition.
People with this condition who have developed a coma, heart inflammation, liver problems, or pneumonia are more likely to die. With early treatment, the death rate is reduced.
These complications may occur:
When to Contact a Medical Professional
Contact your health care provider right away if you develop a fever after returning from a trip. Possible infections need to be investigated in a timely manner.
Wearing clothing that fully covers the arms and legs when you are outdoors can help prevent TBRF infection. Insect repellent such as DEET on the skin and clothing also work. Tick and lice control in high-risk areas is another important public health measure.
Horton JM. Relapsing fever caused by borrelia species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 242.
Petri WA. Relapsing fever and other borrelia infections. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 322.
Review Date: 12/1/2018
Reviewed By: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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