Relapsing Fever Explained – What You Need to Know

If you’ve ever heard the term “relapsing fever” and wondered if it’s something serious, you’re not alone. It’s a bacterial infection that shows up with high fevers, chills, and then disappears—only to come back again after a few days. The cycle of fever, recovery, and relapse can be scary, but understanding why it happens makes it easier to handle.

Relapsing fever is caused by spirochete bacteria in the genus Borrelia. These tiny bugs hitch a ride on soft ticks (the Ornithodoros species) or body lice. When an infected tick bites you, it injects the bacteria straight into your blood. In areas with poor hygiene, lice can do the same thing.

Symptoms and Diagnosis

The first sign is usually a sudden fever that shoots up to 104°F (40°C) within hours. You’ll feel chills, headaches, muscle aches, and sometimes a rash. After a day or two, the fever drops, you start feeling better, and then—boom—a second fever wave hits. This pattern can repeat three or four times.

Other common clues include:

• Joint pain that moves around
• Nausea or vomiting
• Sweats after the fever breaks

If you live in a region where relapsing fever is known—like parts of Africa, Asia, South America, or some rural U.S. areas—tell your doctor about recent tick bites or lice exposure. Diagnosis is usually done with a blood test that looks for the bacteria under a microscope or uses PCR to detect its DNA.

Treatment and Prevention

Good news: relapsing fever responds well to antibiotics. Doctors typically prescribe doxycycline, tetracycline, or erythromycin for about 7‑10 days. Starting treatment early shortens the illness and prevents complications like organ damage.

To keep the bug away, focus on two simple steps:

1. Control ticks and lice. Keep your home clean, wash bedding in hot water, and use insect repellents when you’re outdoors. In areas with known tick problems, sleep on raised beds or use tick‑proof mattress covers.
2. Avoid bite sites. Wear long sleeves and pants in grassy or brushy places. Check your skin after hikes and remove any ticks promptly—grab the tick close to the skin with tweezers and pull straight out.

If you suspect a relapse, don’t wait for the fever to spike again. Contact your healthcare provider right away; a short course of antibiotics can stop the cycle fast. Also, let anyone you live with know about the infection so they can watch for symptoms and get checked if needed.

Relapsing fever isn’t common in most cities, but when you travel to rural or tropical spots, it’s worth keeping an eye on tick bites and lice. Simple habits—clean bedding, prompt tick removal, and timely medical care—go a long way toward staying healthy.