Lyme Disease Coinfections: Babesia, Bartonella, Anaplasmosis, Ehrlichiosis, and Powassan Virus

Multiple pathogens may be transmitted in a single tick bite
Coinfections can change symptoms, diagnosis, and treatment
Recognizing them may improve recovery

Lyme disease coinfections can be clinically significant. The tick bite that transmits Borrelia burgdorferi may also carry additional pathogens. When multiple infections are transmitted together, symptom patterns may become more variable, diagnostic interpretation more complex, and recovery trajectories less predictable.

This page serves as the coinfection framework within the broader structural discussion of Why Lyme Disease Tests the Limits of Medicine. It explains how layered infections may influence symptoms, testing reliability, treatment decisions, and recovery patterns.

Understanding coinfections may help explain why some patients do not respond as expected to standard Lyme therapy and why symptom patterns can differ considerably between patients.

What Are Lyme Disease Coinfections?

Coinfections are additional infections present alongside Lyme disease. They may be transmitted during the same tick bite or acquired through a separate exposure. These may include:

• Bacterial infections, such as Bartonella, anaplasmosis, and ehrlichiosis
• Parasitic infections, such as Babesia
• Viral infections, such as Powassan virus

Each infection has distinct clinical features, diagnostic challenges, and treatment requirements. When multiple pathogens coexist, their symptoms may overlap, making it difficult to determine which infection is responsible for a particular complaint.

A person can also contract Babesia, anaplasmosis, ehrlichiosis, Powassan virus, or another tick-borne infection without having Lyme disease. The term “Lyme coinfection” describes infections that may occur with Lyme disease; it does not mean that Lyme disease must always be present.

For broader symptom patterns, see the Lyme Disease Symptoms Guide.

Why Lyme Coinfections Matter

Coinfections can alter the clinical picture in different ways.

• Babesia may be associated with air hunger, drenching night sweats, fever, chills, temperature dysregulation, and severe fatigue.
• Bartonella has been associated with neuropsychiatric symptoms, burning pain, vascular manifestations, swollen glands, and autonomic instability.
• Anaplasmosis and ehrlichiosis often present acutely with fever, headache, muscle pain, and characteristic laboratory abnormalities.
• Powassan virus may cause meningitis, encephalitis, seizures, or other neurologic complications.

These infections do not necessarily respond to standard Lyme antibiotic therapy. A medication that is effective against Borrelia burgdorferi may have little or no activity against a parasite or virus.

When a coinfection remains unrecognized, a patient may appear resistant to Lyme treatment even though another pathogen requires a different therapeutic approach. Persistent symptoms do not prove that a coinfection is present, however, and other infectious and noninfectious explanations may also require evaluation.

For diagnostic interpretation challenges, see Lyme Test Accuracy.

What a 2026 Review Adds

A 2026 review emphasized that coinfections may do more than add separate symptoms. Interactions among pathogens and the immune system may influence disease severity, symptom duration, and treatment response.

However, the authors also identified substantial evidence gaps. Large clinical studies have not yet established how often specific coinfections alter the course of Lyme disease or which treatment combinations produce the best outcomes.

The review supports considering coinfections when the clinical pattern is atypical, but testing and treatment decisions still require individualized clinical judgment.

Lyme Disease Coinfections List

Babesia — A malaria-like parasite that infects red blood cells. Babesia may be associated with air hunger, night sweats, fever, chills, and profound fatigue.

Bartonella — A bacterial infection associated with neuropsychiatric symptoms, burning foot pain, vascular manifestations, swollen glands, and autonomic dysfunction.

Anaplasmosis — An acute febrile illness that affects white blood cells and may cause fever, headache, muscle aches, low white blood cell counts, low platelets, and elevated liver enzymes.

Ehrlichiosis — A bacterial tick-borne infection that can resemble anaplasmosis, with fever, headache, fatigue, muscle pain, and overlapping laboratory abnormalities.

Powassan virus — A rare but potentially severe viral infection that may cause meningitis, encephalitis, seizures, confusion, or long-term neurologic complications.

Lyme Coinfections Symptoms Chart

Coinfection	Type of pathogen	Common symptom clues	Treatment considerations
Babesia	Parasite	Night sweats, air hunger, chills, fatigue, fever	Often requires antiparasitic therapy
Bartonella	Bacteria	Burning pain, neuropsychiatric symptoms, swollen glands, vascular findings	May require targeted antibiotic treatment
Anaplasmosis	Bacteria	High fever, headache, muscle aches, low white blood cells, low platelets	Doxycycline is commonly used
Ehrlichiosis	Bacteria	Fever, headache, fatigue, muscle pain, abnormal blood counts	Doxycycline is commonly used
Powassan virus	Virus	Neurologic symptoms, meningitis, encephalitis, seizures	Supportive care; no specific antiviral treatment

Diagnosing Lyme Coinfections

Laboratory testing for coinfections can have limitations, particularly early in an illness, after partial treatment, or when the level of an organism in the sampled blood is low.

• Babesia blood smears may miss low-level parasitemia.
• Babesia antibody testing may not distinguish active from past infection.
• Bartonella serology may lack sensitivity in some patients.
• PCR testing may be helpful in selected cases but can be negative when organisms are not present in the sampled blood.
• Anaplasmosis and ehrlichiosis testing may become less informative after antibiotics or outside the acute phase.
• A standard Lyme disease test does not determine whether Babesia, Anaplasma, Ehrlichia, or Powassan virus is present.

Because no single test answers every question, the clinical pattern remains important. Fever, drenching sweats, air hunger, burning foot pain, low blood counts, elevated liver enzymes, neurologic symptoms, and an atypical response to treatment may all influence the evaluation.

A positive antibody test must also be interpreted carefully. Depending on the pathogen and test, it may indicate previous exposure rather than prove that an infection is currently responsible for the patient’s symptoms.

Can Lyme Treatment Miss a Coinfection?

Yes. An antibiotic prescribed for Lyme disease may treat certain bacterial coinfections but will not address every infection carried by a tick.

Doxycycline is commonly used for Lyme disease, anaplasmosis, and ehrlichiosis. It does not treat Babesia, which is a parasite, and antibiotics do not eliminate Powassan virus.

This distinction may become important when some symptoms improve while others continue. However, incomplete improvement does not automatically establish a coinfection. The original diagnosis, treatment course, testing limitations, immune response, tissue injury, medication effects, and unrelated medical conditions may also influence recovery.

Coinfections and Persistent Symptoms

Unrecognized coinfections may contribute to persistent symptoms after Lyme treatment, but they represent only one possible explanation.

Coinfections may amplify inflammatory signaling, autonomic instability, or nervous system sensitization, potentially contributing to greater symptom fluctuation. Evidence remains incomplete, and the contribution of each pathogen may be difficult to separate in an individual patient.

These overlapping biological contributors are explored in Persistent Lyme Disease Mechanisms.

Coinfections and Recovery Variability

Recovery patterns may differ when multiple pathogens are involved. Some patients may require sequential or layered treatment approaches before stabilization occurs, while others improve after treatment directed at one dominant infection.

Coinfections are not the only reason recovery varies. The timing of diagnosis, severity of illness, organ involvement, immune response, treatment tolerance, and other medical conditions can also affect the course of recovery.

Fluctuating recovery patterns are discussed further in the Recovery from Lyme Disease Hub.

Frequently Asked Questions

What are Lyme disease coinfections?

Lyme disease coinfections are additional infections present alongside Borrelia burgdorferi. Commonly discussed examples include Babesia, Bartonella, anaplasmosis, ehrlichiosis, and Powassan virus.

Can you have a tick-borne coinfection without Lyme disease?

Yes. Babesia, anaplasmosis, ehrlichiosis, Powassan virus, and other tick-borne infections can occur without Lyme disease. They are separate infections even though they may be transmitted by the same tick species.

Can one tick carry multiple infections?

Yes. A single tick may carry and potentially transmit more than one pathogen, although the presence of several pathogens in a tick does not mean that all will necessarily be transmitted.

Which Lyme coinfection causes night sweats?

Babesia is the infection most commonly associated with drenching night sweats, air hunger, chills, fever, and profound fatigue. These symptoms are not specific to Babesia and require appropriate clinical evaluation.

How are Lyme coinfections diagnosed?

Diagnosis may involve blood smears, PCR, antibody testing, blood counts, liver enzymes, exposure history, and clinical pattern recognition. The appropriate evaluation depends on the suspected pathogen and stage of illness.

Clinical Takeaway

Lyme disease coinfections may contribute to symptom variability, diagnostic complexity, differences in treatment, and fluctuations during recovery.

Effective evaluation requires considering whether one pathogen explains the entire clinical picture while also recognizing that persistent symptoms do not automatically prove another active infection.

Recognizing possible coinfections can help clinicians interpret unexpected symptoms or treatment responses without losing sight of other infectious and noninfectious explanations.

Related Articles

These articles explore individual coinfections, symptom patterns, and the possibility of multiple pathogens from one tick exposure:

Can One Tick Bite Cause Multiple Diseases?
Babesia Air Hunger
Night Sweats and Lyme Disease
Autonomic Dysfunction and Lyme Disease
Babesia Treatment

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

References

1. Centers for Disease Control and Prevention. About ticks. CDC.
2. Waked R, Krause PJ. Human babesiosis. Infect Dis Clin North Am. 2022;36(4):655–672.
3. Krause PJ, Auwaerter PG, Bannuru RR, Branda JA, Falck-Ytter YT, Lantos PM, Lavergne V, Meissner HC, Osani MC, Rips JG, Sood SK, Vannier E, Vaysbrot EE, Wormser GP. Clinical practice guidelines by the Infectious Diseases Society of America: 2020 guideline on diagnosis and management of babesiosis. Clin Infect Dis. 2021;72(2):e49–e64.
4. Breitschwerdt EB. Bartonellosis, One Health and all creatures great and small. Vet Dermatol. 2017;28(1):96–e21.
5. Popov G, Bashchobanov D, Andonova R. Tick-borne co-infection in Lyme disease: Clinical impact, diagnostic challenges, and therapeutic perspectives. Microorganisms. 2026;14(2):325.

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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