Babesia and Lyme — it’s worse than you think

Babesia and Lyme — it’s worse than you think

Babesia, a tick-borne infection that causes malaria-like symptoms, has been making headlines over the past two years as the number of reported cases increases, and concerns grow over the seriousness of the disease and its ability to be transmitted through the blood supply.

Although Lyme disease is the most talked about tick-transmitted disease, Babesia is more common than you might think. In the 2015 issue of Trends in Parasitology, Diuk-Wasser and colleagues report that up to 40% of patients with Lyme disease experienced concurrent Babesiosis. [1]

This means that out of the estimated 300,000 cases of Lyme disease reported annually in the U.S., 120,000 of those individuals may also have Babesia. This is particularly alarming given that the disease can go undetected in asymptomatic individuals and is transmissible through blood transfusions or congenitally. Additionally, Babesia requires different treatment than Lyme disease.

The Babesia microti (B. microti) parasite that leads to Babesia is commonly seen in blacklegged deer ticks. But according to the authors, it’s also common to find ticks and enzootic hosts carrying both Borrelia burgdorferi (the causative agent of Lyme disease) and B. microti. In fact, between 12% and 42% of rodents are co-infected with both agents. This would suggest that “coinfection provides a survival advantage for both pathogens.” [1]


Source: CDC. Number of Babesiosis cases since it become a nationally reportable disease in 2011.

The first case of Babesiosis caused by the B. microti parasite was identified in 1969 in an individual who had vacationed in Massachusetts. It wasn’t until 2011, that it became a nationally notifiable disease with more than 1100 cases reported by the Centers for Disease Control and Prevention (CDC). Two years later, this number had risen to nearly 1800.

Setty and colleagues summarized their concern in a 2003 review, “Parasitemia in humans is transient and episodic. For this reason, there is a risk of asymptomatic donors transmitting the disease to recipients.” The authors raised concerns that there were 20 cases of Babesiosis and a variant Babesia strain called WA1 by red blood cells and blood component transfusions by 2003.

Babesia can lead to serious illness. Patients have presented with atrial fibrillation, [2] noncardiogenic pulmonary edema, [3] and anemia. [2] In New York, between 1982 and 1991, 7 people with Babesia died, while another patient on Nantucket Island developed pancarditis and died. [4]

Babesia occurs in individuals without the risk factors of increased age, prior splenectomy, immunosuppression, prematurity, and liver disease. [2] In one study of 192 patients, the average age was 46 years for individuals with Babesia. [5] The ages ranged from 27 to 83 years in a New York case series. [6] Five of 192 patients were immunosuppressed, [5] while none of the four subjects in another study had a splenectomy. [2]

Babesia can increase the severity of Lyme disease. Coinfected patients were more likely to have experienced fatigue, headache, sweats, chills, anorexia, emotional lability, nausea, conjunctivitis, and splenomegaly more frequently than those with Lyme disease alone. [7] 

Babesia can also increase the duration of illness with Lyme disease. Babesia patients can remain symptomatic for years with constitutional, musculoskeletal, or neurological symptoms. One study found that 50% of coinfected patients were symptomatic for 3 months or longer, compared to only 4% of patients who had Lyme disease alone. [7] Meanwhile, one-third of patients with a history of both Babesia and Lyme disease remained symptomatic an average of 6 years. [2]

“The clinical pictures for 3 out of our 4 coinfected patients included a large number of symptoms, and 1 coinfected patient had persistent fatigue after treatment,” according to a study by Steere and colleagues. [8] [bctt tweet=”Babesia and Lyme — it’s worse than you think” username=”DrDanielCameron”]

Babesia – difficult to diagnose 

Equally worrisome is the fact that the disease can be difficult to diagnose based on symptoms. Nearly all patients with Babesia reported sweats. However, if the patient was coinfected with Lyme disease, the incidence of sweats dropped to 42%. Sweats can also be reported in other tick borne illnesses. [5]

Blood sample for babesia parasite testingBabesia can also be difficult to diagnose with current testing. The parasite was detected microscopically in as few as one-third of patients with Babesia. [5] Specific amplifiable DNA and IgM antibody were more likely to be positive. [5] The reliability of tests for Babesia in actual practice remains to be determined.

The Babesia tests can become negative. The Babesia sporozoites can be too few in number to be detected on a thin smear or can resolve with or without treatment. It’s been reported that a positive serologic test for B. microti will decay over time, leading to a negative test. Half of the patients with positive serologic tests for B. microti were negative on follow-up. [2]

Treating Babesia  

Babesia cannot be treated with the same medications used to treat Lyme disease. Doxycycline is effective for Lyme disease, Ehrlichia, and Anaplasmosis but not for Babesia.   Treatment with Mepron and Zithromax has been effective for Babesia. Quinine and clindamycin have also been effective but are associated with a higher rate of side effects. Flagyl and Tindamax drugs have been proposed but not well studied. The optimal treatment for Babesia has yet to be worked out.

Physicians have different views over the diagnosis and treatment of Babesia. The Infectious Diseases Society of America’s (IDSA) guidelines advise:

  1. Symptomatic patients whose serum contains antibody to Babesia but whose blood lacks identifiable Babesia parasites on smear or Babesia DNA by PCR should not receive treatment.
  2. Treatment is also not recommended for asymptomatic individuals, regardless of the results of serologic examination, blood smears, or PCR.
  3. Asymptomatic patients with positive Babesial smears and/or PCR should have these studies repeated, and a course of treatment should be considered if Parasitemia persists for >3 months. [9]

There are physicians who have elected not to treat Babesia patients, who are asymptomatic. In 1998, Krause and colleagues reported, “24 of 46 Babesia-infected subjects, who received no specific treatment, had Babesia DNA detectable in their blood for an average of 82 days.” [10]

In 2002, Krause et al reported, “Because symptoms had resolved or improved by the time concurrent Babesiosis or HGE was diagnosed, therapy was not administered to 38 (58%) of the patients with Lyme disease plus Babesiosis.” [5]

There are physicians concerned that symptoms of Babesia may be overlooked when evaluating patients. [11] The symptoms of chronic Lyme disease were overlooked for up to 14 years until reported in the 1990 New England Journal of Medicine by Logigian et al. [12] Meanwhile, the symptoms of Lyme disease were dismissed in by the IDSA Lyme disease guideline committee in 2000 and 2006 as nothing more than the aches and pains of daily living. [11] And the severity of the chronic manifestations were not validated until the 4 National Institutes of Health (NIH) sponsored clinical trials were completed. [13]



  1. Diuk-Wasser MA, Vannier E, Krause PJ. Coinfection by Ixodes Tick-Borne Pathogens: Ecological, Epidemiological, and Clinical Consequences. Trends Parasitol, (2015).
  2. Wang TJ, Liang MH, Sangha O et al. Coexposure to Borrelia burgdorferi and Babesia microti does not worsen the long-term outcome of lyme disease. Clin Infect Dis, 31(5), 1149-1154 (2000).
  3. Golightly LM, Hirschhorn LR, Weller PF. Fever and headache in a splenectomized woman. Rev Infect Dis, 11(4), 629-637 (1989).
  4. Marcus LC, Steere AC, Duray PH, Anderson AE, Mahoney EB. Fatal pancarditis in a patient with coexistent Lyme disease and babesiosis. Demonstration of spirochetes in the myocardium. Ann Intern Med, 103(3), 374-376 (1985).
  5. Krause PJ, McKay K, Thompson CA et al. Disease-specific diagnosis of coinfecting tickborne zoonoses: babesiosis, human granulocytic ehrlichiosis, and Lyme disease. Clin Infect Dis, 34(9), 1184-1191 (2002).
  6. Meldrum SC, Birkhead GS, White DJ, Benach JL, Morse DL. Human babesiosis in New York State: an epidemiological description of 136 cases. Clin Infect Dis, 15(6), 1019-1023 (1992).
  7. Krause PJ, Feder HM, Jr. Lyme disease and babesiosis. Adv Pediatr Infect Dis, 9, 183-209 (1994).
  8. Steere AC, McHugh G, Suarez C, Hoitt J, Damle N, Sikand VK. Prospective study of coinfection in patients with erythema migrans. Clin Infect Dis, 36(8), 1078-1081 (2003).
  9. Wormser GP, Dattwyler RJ, Shapiro ED et al. The clinical assessment, treatment, and prevention of lyme disease, human granulocytic anaplasmosis, and babesiosis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis, 43(9), 1089-1134 (2006).
  10. Krause PJ, Spielman A, Telford SR, 3rd et al. Persistent parasitemia after acute babesiosis. N Engl J Med, 339(3), 160-165 (1998).
  11. Cameron DJ, Johnson LB, Maloney EL. Evidence assessments and guideline recommendations in Lyme disease: the clinical management of known tick bites, erythema migrans rashes and persistent disease. Expert Rev Anti Infect Ther, 1-33 (2014).
  12. Logigian EL, Kaplan RF, Steere AC. Chronic neurologic manifestations of Lyme disease. N Engl J Med, 323(21), 1438-1444 (1990).
  13. Cameron DJ. Clinical trials validate the severity of persistent Lyme disease symptoms. Med Hypotheses, 72, 153-156 (2008).

372 Replies to "Babesia and Lyme — it’s worse than you think"

  • Melissa Linger
    10/11/2017 (3:48 pm)

    My 11-year-old son tested positive for Babesia using the DNA Conexions test. The LLMD we were using only prescribed herbs and they did not work. We need to find another medical professional. What treatment should we seek? He has many symptoms and is missing out on a normal childhood.

    • Dr. Daniel Cameron
      10/11/2017 (11:09 pm)

      I am not certain the significance of the urine test you are referring to. It is challenging to validate each test. You might need to add a doctor familiar with antibiotics for tick borne illnesses. You will also need to work with other doctors to rule out other causes.

  • Bonnie
    10/02/2017 (1:49 am)

    I had my first lyme test in november and all IGGs and IGMS were positive. Now, I have only one IGM absent, and still have a 5.09 lyme test value. Been on doxy for 5 weeks, malarone for 7 months and zithro for 5 months – do your titers stay elevated even if the lyme is gone? I also have babesia – when do you know when you are well enough to get off the meds. I am good for the most part, but every day around 6-7 PM I get really fatigued. Since it is like clockwork, makes me wonder if it is the bugs anymore, or the meds.

    • Dr. Daniel Cameron
      10/02/2017 (4:12 pm)

      The titers typically remain elevated even if the infection has resolve. Your doctor will have to use clinical judgement including ruling out other infections

  • Mitchell
    09/29/2017 (8:30 pm)

    After 6 nights of night sweats, chills, headache behind eyes and 103+ fever my 24 year old son received an equivocal result for acute lyme and negative for long term lyme. The babesia test results done by the ER won’t be back for 2 weeks. He has started on 100mg doxy 2x per day for 21 days. Should we be treating for babesia NOW based on symptoms? We live in Massachusetts.

    • Dr. Daniel Cameron
      09/29/2017 (9:13 pm)

      There are sweats from other tick borne illnesses.

    • Rebecca
      10/23/2017 (1:51 pm)

      Doxycycline for 21 days? Might as well put a gun to the poor guys head and save him a lifetime of suffering. Bring him to a real lyme doc. Tests are garbage.

    • Mai
      02/04/2018 (1:00 am)

      21days it’s not enough, they did the same to me and I have been having a lot of pain for 10 years and now I had life treating symptoms, very bad neurological problems. This is really serious, don’t waste your time, you need a serious treatment and evaluation I had Bartonella and nobody realize. Please look for help. Dr. Mozayeni in Maryland knows how to treat this. DON’T TRUST IN DOCTORS WHO THINK YOU CAN BEAT LYNE WITH 21 days of antibiotics.

      • Susan Ryan
        07/27/2019 (4:08 pm)

        I was infected as a child in the mid to late sixties. I actually had the rash but LD was not known and we thought it was a spider bite. I had recurring illness (with periods of wellness) in between every 6-8 years. As a chemist, I saw an occupational health provider for possible exposure to paclitaxel in my late 30s. I had very severe illness, the nervous system is the most symptomatic and including petit mal seizures. The doctor recognized I had untreated Lyme disease. From there, i found Dr Sam Donta, who treated me and my children with tetracycline 500 mg 3xday for a very long period. I was on and off the tetracycline for two years, followed by a brief course of Biaxin and plaquenil, which gave me severe Herx, followed by 12 years of relative wellness. Every few years I would take tetracycline for 2 weeks. Then, about 4 years ago, symptoms worsened. I was seeing the drs at Northampton Wellness and still working for several years. Reoccurrence of petit mal seizures then prevented me from driving and I could no longer work. I am now dedicated to working with a more local doctor and hitting it with everything I can. I am 60 and have been living with Babesia, Bartonella and borrelia almost all of my life. I understand why the most common cause of death for people with chronic Lyme disease is suicide. But I fight on.

        • Naomi
          01/07/2023 (4:54 pm)

          Right there with you. Pretty sure I was born with it in 67, but, can trace it back to three months before I turned 9 for sure. In and out of flares my whole life. Each one getting stronger and lasting longer, to now, where it just doesn’t go away. Ruined my heart, teeth and more. Been told nothing I can do, yet I still can’t get disability, even for a messed up double bypass. So, I just fight. If that means I filled a water glass for the day, and that is it, I count it as a win. Three years ago, they gave me 2 years to live. So, I am winning!!!!

  • Ace
    09/24/2017 (5:13 pm)

    During a routine blood donation I was notified that babesia PCR was positive. I was bit 1 month prior and my PCP gave me antibiotics as a precaution to contracting Lyme’s. I was told by my doctor after receiving the information from the blood donation clinic that because I was not experiencing symptoms I could not be treated and my body would eliminate the pathogen. I was just tested again 3 months after being bit. I’m now being put on 1 week of medications. Do you think this is enough time to kill this infection? I’ve read places that say min 10 days of treatment. I want to get rid of this parasite sooner than later.

    • Dr. Daniel Cameron
      09/24/2017 (6:42 pm)

      There are often symptoms of Babesia during followup. There are also periods of time without symptoms making it difficult for blood banks to detect Lyme disease. The ten day recommendations for Babesia were proposed based on the original study comparing a combination of Mepron and Zithromax vs Clindamycin with Quinine. They were able to clear Babesia from the red cells. I often find longer patients more effective if symptomatic. Doctors are divided.

  • Paige
    09/22/2017 (8:06 pm)

    Do you know if Babesia has been found in humans in Hawaii? Also, can Babesia symptoms come and go similar to MS and Lyme? I was diagnosed in 2013 with Guillain-barre but have since had two relapse episodes of extreme weakness and the last one left me with continued weakness, fatigue, and pain. Neurologist said it is not Guillain-barre but doesn’t know what it is and rheumatologist diagnosed me with fibromyalgia. I am beginning to wonder if I had tick paralysis in 2013 and got a rickettsial disease.

    • Dr. Daniel Cameron
      09/23/2017 (7:57 am)

      I am no familiar with the tick borne issues in Hawaii.

    • Linzie
      01/29/2018 (11:54 am)

      You may want to talk to your neurologist about transverse myelitis or NMO (neuromyelitis optica), although this sounds more like transverse myelitis (TM). I have chronic lyme, recent babesia contraction from a blood transfusion, and transverse myelitis. All of the tick borne infections were from before transverse myelitis so I absolutely know the different symptoms from lyme and TM. What you’ve explained sounds A LOT like transverse myelitis. Did you have MRIs done of your spine and brain at the onset of weekneas/paralysis? Did they find a lesion in your spine? If not, it still doesn’t preclude the possibility of having TM. I’m assuming you had a lumbar puncture (spinal tap). Did they test for oligoclonal bands, protein, and white blood cells? Again, all can be normal and still be TM. Lyme disease is also a known cause of transverse myelitis. Mine was triggered by mycoplasma pneumonia although the lyme and babesia have hindered my recovery. I am incredibly lucky, however, and am one of the 1/3 who will recover to nearly 100%. It’s a disease that’s actually even more rare than Guillian-Barré (only 1,400 cases per year in the U.S.) and there are very few neurologists who are even well educated on the disease. You can always send all of your original medical files from the Guillian-Barré diagnosis to Johns Hopkins Transverse Myelitis Center and they will help give you a diagnosis. If you’re curious if this is possibly what is going on, I recommend the Facebook group Transverse Myelitis Folks (Blue Crew). Just my two cents from someone who has experienced all three illnesses.

      • Dr. Daniel Cameron
        02/01/2018 (12:52 am)

        Thanks for your comments. They reflect how little we know.

      • Mai
        02/04/2018 (12:54 am)

        Could you please tell me more about your Babesia symptoms? I am recovering from Bartonella but I am not sure if heat sensitivity is due to Babesia. Thanks

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