Babesia anaplasmosis co-infection can cause serious complications—including confusion. In this Inside Lyme case study, I discuss a 78-year-old woman who presented with cognitive impairment from two tick-borne infections at once.

Paparone and colleagues describe this case in the journal Nurse Practitioner.

The Case: Babesia Anaplasmosis Causing Confusion

A 78-year-old woman was evaluated in an emergency room with fever, chills, lethargy, fatigue, and confusion. Her maximum temperature was 100.6°F.

Her blood tests were quite abnormal. She had severe anemia, low white blood count, and low platelet count:

1. Anemia (dropped from 10.5 g/dL to a low of 8 g/dL)
2. Leukopenia (dropped from 5.0 × 10⁹/L to 2.6 × 10⁹/L)
3. Thrombocytopenia (dropped to 39 × 10⁹/L)

The doctor initially considered sepsis—a potentially life-threatening illness triggered by infection. The body’s immune response can be so strong that the body attacks itself, leading to organ damage and death.

She also had multiple tick bites.

Diagnosing the Babesia Anaplasmosis Co-Infection

The doctors were able to identify the parasite that causes Babesia in the woman’s red blood cells under the microscope. Babesia microti is transmitted by the same tick that carries Lyme disease.

The doctors prescribed a combination of atovaquone and azithromycin for her Babesia infection. These medications are marketed under the names Mepron and Zithromax in the US.

The doctors were also concerned that the woman might suffer from another tick-borne illness called Anaplasmosis because of her low white blood count and low platelet count. Anaplasmosis had previously been called Ehrlichia.

The combination of atovaquone and azithromycin is not effective for Anaplasmosis. The doctors added doxycycline to the woman’s treatment.

The laboratory tests confirmed that she had, in fact, a babesia anaplasmosis co-infection. The IgM tests were positive for both conditions, consistent with early infection.

The woman’s cognitive function improved dramatically following two weeks of treatment, according to the authors.

Why Babesia Anaplasmosis Co-Infection Is Dangerous

This case illustrates several critical points about co-infections:

1. Tick-borne diseases can lead to confusion in the elderly
2. An individual with a tick-borne infection can be confused with sepsis
3. Babesia and Anaplasmosis require different treatments—missing one can be dangerous
4. Standard Babesia treatment (atovaquone/azithromycin) does NOT treat Anaplasmosis

If the doctors had not considered Anaplasmosis and added doxycycline, this patient might have had a very different outcome.

Questions This Case Raises

1. How many elderly patients with tick-borne illnesses are confused?
2. What if the parasites had not been seen under the microscope? Would Babesia testing have been ordered?
3. What might have happened if the doctors had not considered Anaplasmosis?
4. Could this woman’s short-term confusion lead to long-term cognitive impairment?

Editor’s Note

In my practice, each individual requires a careful assessment. That is why I order a broad range of blood tests for other illnesses in addition to tick-borne infections. I also arrange consultations with specialists as needed.

Many patients are complex, as highlighted in this Inside Lyme Podcast series.

We need more doctors with skills diagnosing and treating Lyme disease in the elderly. Professionals evaluating confused elderly patients should remember to look for tick-borne infections—especially Babesia co-infection—and treat accordingly.