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.


by Daniel J. Cameron, MD, MPH

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.

A commentary, published in July 2015, entitled Time to Become Familiar with Babesiosis?  highlights the concern among those in the medical community. The article points out, “Babesiosis is the single most common transfusion-related infection.”

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]

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).

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

  • Mary
    08/02/2017 (7:10 pm)

    I am also interested in the correlation between elevated creatinine/BUN and kidney disease. My husband has been told that he has third stage kidney disease. We have had multiple tick bites (Hudson River Valley) and now wonder if babesia treatment might be indicated. No LLMD on board, unfortunately.

    • Dr. Daniel Cameron
      08/02/2017 (11:40 pm)

      Kidney disease has been reported due to Lyme disease. I have not seen any literature addressing your question. Sorry

  • Crissy Naticchia
    08/20/2017 (8:32 pm)

    My husband of 50 years old recently passed away from Babesia. He has a splenectomy when he was a child and by the time this illness was diagnosed, it was too late for him. His liver and kidneys shut down and the doctors treated him for alcohol withdrawal. I would love to see more awareness of babesia out there.

    • Cheryl
      01/18/2018 (3:43 am)

      My husband had liver kidney failure as well, which I believe stemmed from Babesia (Positive FISH). His infectious disease doctors said the test was “invalid” but he responded to the Babesia treatment. Unfortunately it was too late and he went into full liver/kidney failure. He received a liver/kidney transplant in May 2017, but the liver is again showing signs of severe inflammation.

      • Dr. Daniel Cameron
        01/18/2018 (5:34 am)

        There are shortcomings of all tests including the western blot IgG and IgM patients. Doctors are often left withe clinical judgment when making a treatment decision if a tick borne illness is a possibility. It is also important to rule out other conditions.

  • Deb B
    09/04/2017 (9:36 pm)

    I believe I was bitten over 20 years ago yet I don’t remember it. I was misdiagnosed with fibromyalgia, migraines and multiple psych disorders. I always felt they were missing something. I felt so sick and kept being told I was fine. I just found out I have Lyme Babesia and Bartonella. My regular doctors still don’t believe me but I have a positive clinical diagnosis and a positive iSpot lyme test. It literally explains everything I’ve gone through. I’ve been having scary chronic migraines that no medication will get rid of. I get complete loss of vision for a few seconds, vertigo, dizziness and aura along with swishing in my ears. Also the most awful pressure in my head and ears when standing or changing position. It feels like my pulse. My neck and shoulders hurt too but these are not tension headaches and my no is usually normal. Does this sound like something that could be explained by Lyme or Co Infections? All my Brain imaging has been normal.

    • Dr. Daniel Cameron
      09/04/2017 (10:19 pm)

      You would be reasonable to include include a tick borne evaluation in your workup.

  • Alicia Kwalton
    09/14/2017 (5:26 am)

    I was bitten by an insect on August 9, 2014 while lying in my bed. I broke out in hives, went to the ER and my heart just went off. I was hospitalized for 9 days on the cardiac floor. No one could tell me what was happening. Since then I have experienced pericarditis, tachycardia and since December, significant pain in my bones. I am desperate for answers. What is a tick borne evaluation?

    • Dr. Daniel Cameron
      09/15/2017 (5:08 am)

      Your doctor has likely already considered Lyme disease. You may benefit from being evaluated again for a tick borne infection by a doctor with experience in that area. You should also continue to look for answers with your cardiologist.

    • Matteo
      09/24/2017 (12:06 am)

      Alicia–where do you live? Have you investigated Chagas, or the cone nosed assassin beetle (kissing bug)? I have heard of severe reactions along these lines.

  • Richard
    09/19/2017 (3:50 am)

    Babesia and Bartonella are nasiter than Lyme disease for most. Babesia can take forever to get rid of sometimes it can take 9-15 months of intensive multi anti-malarial cocktails to eradicate this. A good check on whether you’ve gotten it under control is to check the inflammation of your liver and spleen. Babesia loves to hang out there (then again so does Bartonella). Forget getting tests they are quite inaccurate better off being treated based on symptoms.

    • Dr. Daniel Cameron
      09/19/2017 (4:26 pm)

      The original study only prescribed 10 days of treatment for Babesia. The cases were caught at the time Babesia was in the red cell. The time to resolve Babesia that was not caught early is not as clear.

  • 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.

  • 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.

  • 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.

  • 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

  • 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.

  • roxanne
    11/06/2017 (1:05 am)

    I have babesia and lyme and have been treating for six years without much success. It would appear that Babesia is the biggest player in my illness yet, nothing seems to knock it. Not even Mepron and Azithromycin. My Dr. is now putting me on the dreaded Quinine/Clindamycin protocol. In your experience is one protocol better that the other in you patients?

    • Dr. Daniel Cameron
      11/07/2017 (11:39 pm)

      I prefer Mepron and Azithromycin to avoid the side effects of Quinine and Clinadamycin. Nevertheless Quinine and Clindamycin helps some people. Flagyl and tindamax has been considered for their antiparasite effects but the research has not caught up.

  • Jennifer
    11/26/2017 (8:21 pm)

    Two months ago, I tested positive for Babesia antibodies, but the follow-up smear and PCR were negative. I now have recurrent episodes of fever/chills/aches/sweats/headache and other symptoms, each short in duration (12-48 hrs) with rapid recovery after. I fear my physician will deny treatment due to the test results and my apparent good health, and I will continue to have a lingering low-level infection. Will this infection, if Babesiosis, truly resolve on its own?
    I have been working as a field biologist in MA (Cape/Islands and inland) for 25 years (= major tick exposure). Amazingly, this is my first known tick-borne disease but most of my coworkers have been ill one or more times. I have found many physicians to be (back then and now) a bit slow to the table.

    • Dr. Daniel Cameron
      12/02/2017 (1:51 am)

      Thanks for sharing your concern. The smear and PCR can resolve before testing leaving only the antibody test. I would not dismiss a positive antibody test.

  • Kay
    12/27/2017 (6:04 pm)

    My Lyme and Babesia went undiagnosed for a year, maybe a bit longer. I’ve finally completed the abx part of my treatment, and was feeling almost 100% I’m starting herbal antimicrobials soon to clean up the last bits, but the problem remains my Babesia infection has clung to my body quite stubbornly. I just had a chest episode (the crushing elephant sitting on your chest feeling) and it’s been atleast a month since my last one. Why is this parasite so damn hard to ridd my body of??! My biggest fear is I’ll never fully get back to normal.

    • Dr. Daniel Cameron
      12/27/2017 (10:37 pm)

      Thanks for sharing your frustration. Keep working on getting healthy.

  • Fidmar
    12/29/2017 (4:26 pm)

    I had Lyme Disease 2 years ago and was treated with antibiotics. Recently my bloodwork showed a high indication of Babesia infection, which my doctor said indicated a past infection. I have never felt the same since being diagnosed with Lyme Disease (constant fatigue and joint pain). Can Babesia still be present and flare up? Is it worth following up with a Specialist or Rhuematologist? Thank you for your help.

    • Dr. Daniel Cameron
      01/10/2018 (1:47 pm)

      Babesia is a condition where a IgG “past infection” does not mean that the infection is necessarily gone.

  • Nic
    01/03/2018 (4:28 pm)

    My doctor wants me to take Zithromax/Mepron combo for 4 months because the life cycle of the red blood cell is 110 days.

    Is this necessary? I have having increased brain fog, dizzyness and “spacy” feeling since starting a month and a half ago and it is kind of worrying me.

    • Dr. Daniel Cameron
      01/10/2018 (1:37 pm)

      The life cycle of a red cell is limited. I use clinical judgement based on response rather than tie it to red cells.

  • Tom
    01/07/2018 (3:36 am)

    I had babesia and was hospitalized and treated and retested after treatment.Supposedly I am cured. Why do I still feel totally fatigued and have very poor balance. I have even had to get PT for balance.

    • Dr. Daniel Cameron
      01/10/2018 (1:28 pm)

      The original treatment trial was 10 days for Babesia but those cases were identified early. There are a growing number of case reports where longer therapy and retreatment of Babesis has been described.

  • Bonnie Wilson-Davis
    01/12/2018 (12:04 am)

    I had Babesia caught early, major symptoms cleared within a couple weeks, a few mild symptoms have lingered like balance issues and fatigue and are slowly trailing off after several months. PCR, smears, etc. repeated several times all blood work is negative. Feel like everything is on the wane, but how long (typically) does it take to get completely back to normal? Are there any supplements, herbs, etc. that might help? Thanks.

    • Dr. Daniel Cameron
      01/14/2018 (7:00 am)

      I am happy to hear the major symptoms cleared. Ther are some individuals where they remain ill over time. Some benefit from retreatment for Babesia with retreatment. The trials have not addressed who will benefit from retreatment. Supplements have also been proposed but are also not studied.

  • Katie
    01/18/2018 (7:14 am)

    I have been fighting Lyme, Rocky Mountain Spotted and Babesia Duncani for approx. 4 years. I have had IV pic line for 1 year. Babesia symptoms as wells as Lyme re occurred 7 months after IV removal. I cannot seem to clear the Babesia. I feel that I have tried nearly everything in every combination with only minor relief of symptoms. Is there anything novel you would recommend for the Babs I cant seem to clear? Thanks!

    • Dr. Daniel Cameron
      01/18/2018 (1:29 pm)

      Your case highlights the difficulties we all face when tick borne issues are a concern. Each case needs to be evaluated individually.

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