Relapsing Fever

Relapsing fever is caused by bacteria known as spirochetes, closely related to the organisms that cause Lyme disease. The bacteria may be transmitted to humans by either ticks or lice. The illness is characterized by periods of fever, chills, headaches, body aches, muscle aches, and cough, alternating with periods when the fever subsides and the person feels relatively well. Complications may include bleeding abnormalities, pneumonia, meningitis, cranial nerve palsies, hemiplegia, and coma. Tetracycline, erythromycin, and penicillin have all been used to treat relapsing fever. The first dose of antibiotic is often followed by a severe reaction (Jarisch-Herxheimer reaction) marked by fever, shaking chills, and a fall in blood pressure. There is no vaccine for relapsing fever. However, a recent study in Israel showed that tick-borne relapsing fever could be prevented by giving doxycycline (200 mg the first day, then 100 mg/day for four days) to those with suspected tick bites (see T. Hasin MD et al, New England Journal of Medicine 2006; 355:148-55). Travelers to areas where relapsing fever occurs should be sure to follow tick precautions, as outlined elsewhere, and exercise good personal hygiene at all times.