Babesia: Symptoms, Testing, Treatment, and Lyme Disease

Babesia is a tick-borne parasite that can occur with Lyme disease.
Air hunger, night sweats, and cyclical fatigue are important clues.
Babesia requires different testing and treatment than Lyme disease alone.

Babesia is a malaria-like parasite that often occurs with Lyme disease. It infects red blood cells and may cause fatigue, air hunger, night sweats, chills, fever, anemia, and relapsing symptoms.

Babesia and Lyme disease often occur together, and this co-infection is one reason some patients do not fully recover after Lyme disease treatment.

Some patients continue to experience fatigue, air hunger, night sweats, or relapsing symptoms despite Lyme treatment. Babesia may be part of the explanation.

Babesia requires different testing and treatment than Lyme disease. Standard Lyme antibiotics alone are not sufficient because Babesia is a parasite rather than a bacterium.

For a broader overview, see the Lyme Disease Symptoms Guide.

Babesia Symptoms: Key Signs of Co-Infection

Babesia symptoms overlap with Lyme disease but often include distinct patterns that point to co-infection.

• Night sweats, especially cyclical or drenching sweats
• Air hunger or difficulty getting a full breath despite normal oxygen levels
• Profound fatigue or relapsing exhaustion
• Chills and fever that wax and wane
• Headaches
• Body aches
• Exercise intolerance
• Dizziness or palpitations
• Temperature swings

Night sweats may be mistaken for hormonal changes or menopause symptoms, contributing to delayed diagnosis. Learn more about Lyme disease mistaken for menopause.

Babesia infects red blood cells and may impair oxygen delivery at the cellular level. It may also worsen autonomic dysfunction, amplifying dizziness, breathing discomfort, palpitations, and exercise intolerance.

What Is Babesia?

Babesia is a protozoan parasite that infects red blood cells, similar to malaria.

In the United States, Babesia microti is most common in the Northeast and upper Midwest, while Babesia duncani has been reported more often on the West Coast.

Babesia is transmitted by Ixodes ticks, the same ticks that spread Lyme disease and other tick-borne co-infections.

Once in the bloodstream, Babesia can disrupt red blood cells and contribute to anemia, inflammation, fever, sweats, fatigue, and fluctuating symptoms.

Babesia cases have increased in several regions, reflecting expanding tick populations, greater recognition of babesiosis, and improved awareness of tick-borne co-infections.

What Is the Difference Between Babesia and Lyme Disease?

Babesia and Lyme disease are both transmitted by ticks, but they are not the same infection.

Lyme disease is caused by the bacterium Borrelia burgdorferi and related species. Babesia is caused by a parasite that infects red blood cells.

This distinction matters because treatment is different. Lyme disease is treated with antibiotics directed against bacteria. Babesia requires antiparasitic therapy, often using atovaquone plus azithromycin or other regimens in selected cases.

Patients can have Lyme disease alone, Babesia alone, or both infections together. When both are present, symptoms may be more persistent or complex.

How Is Babesia Diagnosed?

Babesia testing has important limitations, especially when infection levels are low or symptoms fluctuate.

• Blood smears may miss low-level infection.
• Antibody tests may be negative early or may fade over time.
• PCR testing may miss intermittent or low-level infection.
• Different Babesia species may not be equally detected by all tests.

A negative test does not always rule out Babesia. Diagnosis is often based on a combination of exposure risk, symptoms, laboratory findings, and response to treatment.

Babesia should be considered when patients have air hunger, night sweats, chills, relapsing fatigue, anemia, or persistent symptoms despite Lyme disease treatment.

Babesia Treatment: Why Lyme Antibiotics Are Not Enough

Babesia requires antiparasitic treatment. Standard Lyme antibiotics alone are not sufficient.

Common treatment approaches include:

• Atovaquone plus azithromycin
• Clindamycin plus quinine in selected cases

Unlike Lyme disease, Babesia is caused by a parasite rather than bacteria, so antibiotics used alone for Lyme disease are generally not effective against Babesia.

Treatment duration varies depending on symptom severity, immune status, co-infections, laboratory findings, and clinical response.

Some patients require longer treatment, particularly if symptoms persist, relapse occurs, or co-infections are present.

Babesia Co-Infection With Lyme Disease

When Lyme treatment helps but symptoms persist, Babesia is often worth considering.

This parasite can drive persistent symptoms such as fatigue, air hunger, night sweats, chills, and cyclical illness that do not respond to Lyme antibiotics alone.

Babesia may also occur alongside other co-infections, compounding illness complexity and making recovery less straightforward.

Learn more about Lyme disease co-infections.

Can Babesia Cause Air Hunger?

Yes. Air hunger is one of the symptoms patients frequently associate with Babesia. Patients may describe difficulty getting a full breath, frequent sighing, or a sensation that breathing feels manual despite normal oxygen readings.

Air hunger may also overlap with autonomic dysfunction, anxiety-like physiology, anemia, inflammation, or other medical conditions. For more detail, see Babesia Air Hunger.

Can Babesia Cause Night Sweats?

Yes. Night sweats are a classic clue in babesiosis, especially when they are drenching, cyclical, or accompanied by chills, fatigue, fever, or relapsing symptoms.

Night sweats can have many causes, including hormonal changes, infections, medication effects, and other medical conditions. However, in a patient with tick exposure or Lyme disease, Babesia should remain on the differential diagnosis.

Learn more about night sweats and Lyme disease.

Blood Transfusion Risk

Babesia can also be transmitted through blood transfusion, making it unique among many tick-borne infections.

Screening has improved, but awareness remains important, especially for vulnerable patients and those with unexplained fever, anemia, or hemolysis after transfusion.

Who Is at Higher Risk?

Babesia may be more severe in certain groups, including:

• Older adults
• Immunocompromised patients
• Patients without a spleen
• Pregnant individuals
• Infants

These groups may require earlier diagnosis, closer monitoring, and more aggressive or prolonged treatment depending on severity.

Frequently Asked Questions

What is Babesia?

Babesia is a tick-borne parasite that infects red blood cells. It can cause babesiosis and may occur with Lyme disease as a co-infection.

Is Babesia the same as Lyme disease?

No. Lyme disease is caused by bacteria, while Babesia is caused by a parasite that infects red blood cells. They require different treatments.

What are common Babesia symptoms?

Common Babesia symptoms include fatigue, night sweats, air hunger, chills, fever, headaches, body aches, anemia, dizziness, and relapsing symptoms.

Can Babesia cause air hunger?

Yes. Babesia may cause air hunger, a sensation of not getting a full breath, even when oxygen levels appear normal.

Can you have Babesia without Lyme disease?

Yes. Babesia can occur by itself, although it is also commonly discussed as a Lyme disease co-infection because the same ticks can transmit both infections.

Why do doctors miss Babesia?

Babesia can be missed because symptoms overlap with Lyme disease, blood smears may miss low-level infection, antibody tests can be negative early, and PCR testing may miss intermittent infection.

How is Babesia treated?

Babesia is usually treated with antiparasitic therapy, commonly atovaquone plus azithromycin. Clindamycin plus quinine may be used in selected cases.

Can Babesia relapse?

Yes. Babesia can relapse, especially in immunocompromised patients, patients without a spleen, or patients with persistent infection or untreated co-infections.

Clinical Takeaway

Babesia and Lyme disease often occur together, but they are not the same infection. Babesia is a parasite that infects red blood cells and requires different testing and treatment than Lyme disease alone.

When symptoms such as air hunger, night sweats, chills, cyclical fatigue, or relapsing illness persist despite Lyme treatment, Babesia should be considered.

Recognizing Babesia co-infection can help explain incomplete recovery and guide more appropriate testing and treatment.

Related Articles

Learn more about Babesia symptoms, testing, treatment, and Lyme disease co-infections:

Babesia Testing: Why Negative Results Don’t Always Mean Negative
Babesia Air Hunger: When Breathing Feels Manual
Babesia Treatment Duration: When 10 Days Isn’t Enough
Lyme Disease Coinfections: Complete Guide
Lyme Disease Co-Infections Overview

References

1. Krause PJ, et al. Concurrent Lyme disease and babesiosis. JAMA. 1996;275(21):1657-1660.
2. Vannier E, Krause PJ. Human babesiosis. N Engl J Med. 2012;366(25):2397-2407.
3. CDC. Babesiosis. Accessed 2026.

---

Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.

Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention