Borrelia Explained: What You Need to Know

When you hear the word "Borrelia" you probably think of Lyme disease. That's because the bacteria in the Borrelia genus are the main cause of this tick‑borne illness. If you’ve ever been hiking, gardened, or even just walked your dog in a grassy area, you’ve probably wondered how likely you are to pick it up. Let’s break it down in plain English, so you know what to look for and what to do if you suspect an infection.

How Borrelia Gets Into Your Body

Borrelia lives in the gut of black‑legged ticks, also called deer ticks. When a tick bites you and stays attached for at least 24‑36 hours, the bacteria can move from the tick’s mouth into your skin. The longer the tick stays attached, the higher the chance of transmission. That’s why quick removal matters – use fine tweezers, grab the tick close to the skin, and pull straight out.

Geography matters, too. In the United States, most cases show up in the Northeast, Upper Midwest, and Pacific Coast. In Europe, you’ll see Borrelia infections in the UK, Germany, and Scandinavia. If you travel to these spots, keep an eye on your skin after outdoor activities.

Spotting the Signs: Symptoms to Watch

The earliest sign is often a red, expanding rash called erythema migrans. It looks like a bullseye and appears 3‑30 days after a bite. Not everyone gets the rash, but when they do, it’s a red flag.

Other early symptoms include fever, chills, headache, fatigue, muscle aches, and joint pain. These feel a lot like the flu, which can make it tricky to diagnose right away.

If the infection isn’t treated early, it can spread to the nervous system, heart, and joints. You might notice facial palsy (one side of the face droops), shooting nerve pain, irregular heartbeat, or swelling in larger joints like the knee. These later symptoms can show up weeks, months, or even years after the bite.

Getting a Diagnosis

Doctors usually start with a physical exam and a look for that characteristic rash. If the rash is missing, they’ll ask about recent outdoor exposure and run blood tests. The standard tests look for antibodies – the body’s response to Borrelia. Two‑step testing (ELISA followed by Western blot) helps confirm the infection, but early on the antibodies might not be detectable yet.

In some cases, doctors may order a spinal fluid test or imaging if nervous‑system symptoms are present. The key is to bring up any tick bites or rash history, even if you think the tick was removed quickly.

Treatment Options

Antibiotics are the go‑to treatment. For early Lyme disease, a short course of doxycycline (or amoxicillin for kids and pregnant women) usually clears the infection in a few weeks. If you have later‑stage symptoms, doctors might prescribe a longer course or intravenous antibiotics.

Most people feel better within days of starting treatment, but some report lingering fatigue or joint pain. This is called post‑treatment Lyme disease syndrome. Research is still figuring out why it happens, but supportive care, physical therapy, and symptom‑specific meds can help.

Preventing Borrelia Bites

Prevention is all about avoiding tick bites in the first place. Wear long sleeves and pants, tuck pants into socks, and use EPA‑approved repellents that contain DEET or picaridin. After being outdoors, do a thorough tick check – look under arms, behind knees, and in hair. Showering within two hours of returning home can wash away ticks that haven’t attached yet.

If you find a tick attached, remove it right away and clean the bite area with soap and alcohol. Keep the tick in a sealed bag in case you need to show it to a doctor.

Knowing the basics about Borrelia can keep you from panicking if you get a rash or feel sick after a hike. Spot the signs early, get tested, and start antibiotics promptly. With the right steps, most infections are easy to treat and you can get back to enjoying the outdoors without fear.