Can One Tick Bite Cause Three Diseases? A Triple Tick-Borne Infection
One tick bite may transmit multiple infections
Lyme disease, babesiosis, and anaplasmosis can occur together
Severe babesiosis may require red blood cell exchange
Can one tick bite cause three diseases? A single infected tick may transmit more than one pathogen. In this case report, the authors diagnosed an older woman with Lyme disease, babesiosis, and anaplasmosis—a triple tick-borne coinfection. Severe babesiosis was the most apparent cause of her critical illness and required antimicrobial treatment and two red blood cell exchanges.
Coinfections can be difficult to recognize because their symptoms and laboratory findings may overlap. In addition, treatment directed at one infection may not treat another. Recognizing evidence of multiple tick-borne pathogens can therefore be important when an illness is unusually severe or does not improve as expected.
The 74-year-old woman was an avid gardener with chronic obstructive pulmonary disease (COPD), hypertension, and a history of smoking. She was admitted to the hospital with shortness of breath, fatigue, and a cough producing yellowish sputum.
She was lethargic and pale and had peripheral edema. A lung examination revealed crackles in both lower lungs, Kumar and colleagues reported.1
Because community-acquired pneumonia was initially suspected, the patient was treated empirically with ceftriaxone and azithromycin.
The woman did not recall a tick bite and had no history of a rash. However, subsequent laboratory testing provided evidence of babesiosis, Lyme disease, and anaplasmosis.
“We present a case of triple infection with babesiosis, Lyme disease, and anaplasmosis treated with antibiotics and red blood cell (RBC) exchange (erythrocytapheresis).”1
Severe babesiosis required two red blood cell exchanges
Babesiosis is caused by a microscopic parasite that infects red blood cells.
“A peripheral blood smear revealed the presence of intracytoplasmic parasites consistent with Babesia,” Kumar and colleagues wrote.
The woman had hemolytic anemia and severe thrombocytopenia. Her hemoglobin had fallen from a baseline of approximately 15 g/dL to 9.9 g/dL, and her platelet count was 34,000.
Her parasitemia—the percentage of infected red blood cells—was 9.04%. She was treated with atovaquone and azithromycin for babesiosis. Doxycycline was added because the doctors were concerned about Lyme disease or another tick-borne coinfection.
The woman remained hypotensive despite intravenous fluids and required norepinephrine to support her blood pressure. She also required positive-pressure ventilation because of respiratory distress.
Because of the severity of her illness and the high parasite burden, she underwent a red blood cell exchange, also known as erythrocytapheresis.
The published report contains an internal numerical inconsistency. Its abstract states that parasitemia remained at 6.54% after the first exchange, while the detailed case presentation reports 5.54%. In either event, the parasite burden remained high, and the patient remained in shock.
Her kidney function also worsened. The authors attributed the acute kidney injury to pigment-induced nephropathy associated with hemolysis.
Because of her inadequate response and worsening kidney function, the doctors performed a second red blood cell exchange. After the second procedure, parasitemia fell to 1.75%.
Clindamycin was added during the course of her illness. Atovaquone and azithromycin were later discontinued, and quinine was added. The final antimicrobial regimen included clindamycin, quinine, and doxycycline.
The patient’s blood pressure and respiratory condition improved. Her blood counts and kidney and liver function returned to normal after 14 days of antimicrobial treatment.
Older adults, immunocompromised patients, and individuals with significant underlying medical conditions may face a greater risk of severe babesiosis. Selected critically ill patients may require red blood cell exchange in addition to antimicrobial treatment.
Lyme testing was also positive
The patient’s Lyme IgM immunoblot was positive, while her Lyme IgG immunoblot was negative. The authors interpreted the serologic findings as evidence of Lyme disease.
The patient was treated with doxycycline, which is active against Lyme disease and anaplasmosis.
The absence of a recognized tick bite or erythema migrans rash does not exclude Lyme disease or another tick-borne infection. Many patients do not recall being bitten, and not every patient notices a rash.
Nevertheless, serologic results should be interpreted in the context of the patient’s symptoms, exposure history, illness duration, and other laboratory findings. A positive antibody test does not necessarily establish that an infection is responsible for every feature of a patient’s illness.
Anaplasma antibody titers suggested recent or current infection
Testing for Anaplasma phagocytophilum, the bacterium that causes anaplasmosis, showed an IgG antibody titer greater than 1:1024 and an IgM titer of 1:80. The case authors interpreted these results as evidence of recent or current anaplasmosis.
Anaplasmosis can cause fever, fatigue, headache, muscle aches, low white blood cell counts, low platelet counts, and elevated liver enzymes. The infection can become severe, particularly in older adults and people with underlying medical conditions.
However, antibody results must be interpreted cautiously. Paired acute and convalescent antibody testing demonstrating a significant rise in titers provides stronger evidence than a single antibody measurement. PCR is generally most useful during the early stage of illness.
When should doctors suspect more than one tick-borne infection?
The authors emphasized that an atypical clinical presentation or failure to improve as expected may signal the presence of a tick-borne coinfection.
“Patients presenting with an atypical clinical picture of a single pathogen or a lack of improvement with antibiotics after 48 hours require further testing for the presence of other infections,” the authors suggested. “A delay in the diagnosis can lead to an increased risk of complications and disease duration.”1
Symptoms of Lyme disease, babesiosis, and anaplasmosis may overlap. However, certain findings may increase suspicion for coinfection. These include hemolytic anemia, low platelet counts, low white blood cell counts, elevated liver enzymes, persistent fever, sweats, shortness of breath, unexpectedly severe illness, or limited improvement with treatment directed at only one infection.
In this patient, the hemolytic anemia, visible parasites, high parasitemia, thrombocytopenia, shock, and organ dysfunction provided particularly strong evidence that severe babesiosis was driving much of the acute illness.
A second patient also developed three tick-borne diseases
In another case report, Grant and colleagues described a 70-year-old man who presented to the emergency department with fever, ankle edema, and nausea after a presumed insect bite on his ankle one month earlier.2
Testing provided evidence of Lyme disease, Babesia microti infection, and anaplasmosis. His symptoms resolved following treatment with doxycycline, atovaquone, and azithromycin.
The authors suggested considering coinfection when patients remain symptomatic despite appropriate initial treatment or have laboratory abnormalities that are not adequately explained by a single infection.
Can one tick carry multiple pathogens?
Yes. Blacklegged ticks may carry more than one disease-causing organism at the same time. In endemic regions, an individual tick may harbor multiple pathogens, although transmission of every organism during one bite is not guaranteed.
A coinfected tick could potentially transmit Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum during the same feeding.
However, the published case did not document the tick itself, and the patient did not recall a tick bite. Therefore, the report supports the possibility of triple tick-borne infection but cannot prove that all three organisms were transmitted by one particular tick.
Not every person bitten by a coinfected tick will acquire every pathogen. Transmission depends on factors that include which organisms are present in the tick, the duration of attachment, and other biological factors.
These cases illustrate why clinicians may need to look beyond a single diagnosis when an illness is unusually severe, laboratory abnormalities are unexplained, or the patient does not improve as expected.
Frequently Asked Questions
Can one tick bite transmit three diseases?
Yes. A tick carrying multiple pathogens may transmit more than one infection during the same feeding. Lyme disease, babesiosis, and anaplasmosis can occur together, although triple infection appears to be uncommon.
What are the signs of a Lyme, Babesia, and Anaplasma coinfection?
Possible findings include fever, fatigue, headache, muscle aches, sweats, shortness of breath, anemia, low platelet counts, low white blood cell counts, and elevated liver enzymes. Findings vary, and some patients may not recall a tick bite or rash.
Why can babesiosis become severe?
Babesia parasites infect and damage red blood cells. Severe infection can lead to hemolytic anemia, thrombocytopenia, breathing problems, shock, kidney or liver dysfunction, and a high parasite burden. Selected critically ill patients may require red blood cell exchange in addition to antimicrobial treatment.
When should tick-borne coinfections be considered?
Coinfections may be considered when a patient has an atypical illness, unexplained laboratory abnormalities, unusually severe symptoms, or limited improvement after treatment directed at one tick-borne infection.
Can doxycycline treat both Lyme disease and anaplasmosis?
Doxycycline is active against both Lyme disease and anaplasmosis, although the appropriate regimen depends on the patient’s clinical presentation. Doxycycline does not treat babesiosis, which requires different medications such as atovaquone plus azithromycin or, as an alternative, clindamycin plus quinine.
Clinical Takeaway
A single tick may carry and potentially transmit several pathogens, and the resulting illness may not fit neatly within one diagnosis. Lyme disease, babesiosis, and anaplasmosis can produce overlapping findings but require different treatment considerations.
In this case, the blood smear, high parasitemia, hemolytic anemia, thrombocytopenia, shock, and organ dysfunction provided compelling evidence of severe babesiosis. Lyme IgM immunoblot and Anaplasma antibody titers supplied additional evidence that the authors interpreted as two concurrent tick-borne infections.
Severe anemia, high parasitemia, shortness of breath, persistent fever, unexplained laboratory abnormalities, organ dysfunction, or failure to improve as expected may justify evaluating a patient for additional tick-borne infections.
Recognizing possible tick-borne coinfections can help clinicians interpret an atypical presentation and select treatment directed at each clinically supported infection.
This article discusses published case reports for educational purposes. Individual test results and treatment decisions must be interpreted in the context of the complete clinical presentation. This information is not medical advice.
Related Articles
These articles provide additional information about multiple infections transmitted by ticks and the diagnosis and management of tick-borne coinfections.
One Bite, Six Diseases: All From the Same Tick
Babesia Symptoms: Signs, Diagnosis, and Treatment
Anaplasmosis Symptoms: Early Signs and Diagnosis
References
- Kumar M, Sharma A, Grover P. Triple Tick Attack. Cureus. 2019;11(2):e4064. doi:10.7759/cureus.4064.
- Grant L, Mohamedy I, Loertscher L. Triple tick-borne infection with Lyme disease, babesiosis, and anaplasmosis. BMJ Case Reports. 2021;14:e241004. doi:10.1136/bcr-2020-241004.
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
I am Chronic for Lyme. Have suspected Babesia for year as well. One Babesia test was Negative. Lyme tests negative for 30+ years. ( Only positive as of 2021 for Lyme). How and where can I have accurate testing for all TBD’s? What would I expect to pay? Old & sick of this relentless battle. Thank you for any advice.
I have not found local labs or speciality labs as good as I would like. I have had to depend on clinical judgement.
I was recently treated empirically with doxy for presumed Lyme disease and anaplasmosis (tests were eventually positive for recent infection with both) complicated by an opportunistic strep infection (treated with penicillin). My symptoms were fever, unbearable headache, mild sore throat, muscle and joint aches, stiff neck, fatigue, and worsening neuropathy.
Last September, I had a severe concussion followed by a sinus infection and severe covid (October), untreated Lyme and anaplasmosis in late November, and in December, the death of my father and my 95-year-old demented mother’s moving in with me. I have a long history of dysautonomia, migraines, NTM infection (successfully treated, with some residual lung scarring), recurrent pyelonephritis and UTIs, and adrenal insufficiency. However, since this series of fun events, my neuropathy, fatigue, and muscle and joint pain have increased exponentially. My neurologist attributed it to my concussion and stress (without knowing about the tickborne infections), but my question is whether there would be any clinical benefit to another course of doxy or whether I should just accept these changes as the new normal and quit my whining? Thank you.
For background, I live in an area with a very high rate of tick-borne infections–Lyme, babesiosis, and anaplasmosis–so reinfectiom is doubtless inevitable.
I have patients with co-infection to include Babesia where the tests are negative. I have patients who have benefited from treating a co-infection clinically to include treatment for Babesia.