Can Lyme Disease Be Missed in Babesia? Co-Infection Explained
You’re treated for Babesia—but you’re still not better.
Some symptoms improve—but others don’t.
Lyme disease may be missed.
by Daniel J. Cameron, MD, MPH
When patients are diagnosed with a tick-borne illness like Babesia, clinicians often focus on that infection alone. But Lyme disease may be overlooked—even when it is present.
Lyme disease co-infection can be missed when symptoms are attributed to a single diagnosis.
This is where patients can get stuck. Treatment begins—but symptoms persist because not all infections have been identified.
Learn more in our Lyme coinfections guide.
In a case report by Zaiem and colleagues, an elderly man diagnosed with Babesia was later found to also have Lyme disease—an infection that was nearly missed.
This highlights a key issue: even when one tick-borne disease is identified, others may still be present.
Can Lyme Disease Be Overlooked in Tick-Borne Illness?
Yes. Physicians may not always consider Borrelia burgdorferi as a co-infection when another tick-borne disease has already been diagnosed.
This can delay diagnosis and treatment.
Lyme disease has historically been overlooked in patients with complex or atypical presentations, including neurologic and psychiatric symptoms.
In one study, Lyme disease was missed for an average of two years in patients later diagnosed with Lyme encephalopathy (Fallon et al., 2008).
These patients were initially thought to have psychiatric conditions such as depression, anxiety, or cognitive disorders (Fallon & Nields, 1994).
According to a case series by Cameron (2007), Lyme disease may go unrecognized for years—even when patients meet serologic criteria.
What Happens When Lyme Disease Diagnosis Is Delayed?
What did this look like in real patients?
A case series described multiple patients whose Lyme disease went unrecognized for years (Cameron, 2007):
- A man with an early erythema migrans rash who remained ill for 8 years
- A teenager with prior infections who remained ill for 8 years
- A patient with knee swelling misdiagnosed as a meniscus tear for 6 years
- A teen with Bell’s palsy and academic decline for 6 years
- A patient told twice they did not have Lyme disease who remained ill for 3 years
- A patient with negative spinal tap results who remained ill for 3 years
Delayed treatment matters.
Patients with delayed diagnosis were six times more likely to fail initial therapy (Cameron, 2007).
Similarly, patients with Lyme encephalopathy remained ill an average of 9 years after onset when diagnosis was delayed (Fallon et al., 2008).
Why Do Co-Infections Make Lyme Disease Harder to Recognize?
This is where things become more complicated.
Tick-borne illnesses can overlap and complicate diagnosis. Babesia may present with malaria-like symptoms, while Lyme disease can cause neurologic or musculoskeletal symptoms.
When symptoms overlap, one infection may mask another.
In the Zaiem case, the patient was initially treated for Babesia. Lyme disease was only recognized after he developed Bell’s palsy—a symptom seen in a minority of Lyme cases.
This is where pattern recognition matters. Symptoms that evolve or fail to respond to treatment may indicate more than one infection.
Do Co-Infections Affect Severity and Treatment Outcomes?
Yes. Co-infections can lead to more severe illness and more complex recovery.
Studies have shown that patients with both Lyme disease and Babesia may experience:
- More severe symptoms
- Longer duration of illness
- Increased treatment complexity
Krause and colleagues reported increased illness severity when both infections were present, while Steere and colleagues found patients with co-infections had more systemic symptoms.
This is why persistent or unexplained symptoms should prompt reconsideration of co-infection.
When Should Lyme Disease Be Considered as a Co-Infection?
Lyme disease should be considered when:
- Symptoms persist despite appropriate treatment
- Symptoms do not fit a single diagnosis
- Neurologic symptoms develop (e.g., Bell’s palsy)
- Exposure to tick-endemic areas is known
Follow-up matters. Patients treated for one tick-borne disease should be reassessed if symptoms continue or evolve.
Detailed medical history is critical, as prior antibiotic use may alter immune response and testing.
Clinical Takeaway
Lyme disease can be overlooked in patients diagnosed with Babesia and other tick-borne infections.
Co-infections can delay diagnosis, complicate treatment, and worsen outcomes.
If treatment isn’t working as expected, it’s worth asking why—again.
References
- Fallon, B. A., Keilp, J. G., Corbera, K. M., et al. (2008). A randomized, placebo-controlled trial of repeated IV antibiotic therapy for Lyme encephalopathy. Neurology, 70(13), 992–1003.
- Fallon, B. A., & Nields, J. A. (1994). Lyme disease: A neuropsychiatric illness. American Journal of Psychiatry, 151(11), 1571–1583.
- Cameron, D. J. (2007). Consequences of treatment delay in Lyme disease. Journal of Evaluation in Clinical Practice, 13(3), 470–472.
- Zaiem, F., Alkawam, H., Lee, S., & Fabisevich, M. (2015). Severe symptomatic babesiosis co-infection with Lyme disease. QJM: An International Journal of Medicine.
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
