Borrelia Miyamotoi Blood Smear: Why It Fails to Detect Infection
A negative blood smear does not rule out Borrelia miyamotoi infection.
Why Blood Smears Fail to Detect Borrelia miyamotoi
Diagnosing Borrelia miyamotoi can be challenging. Some clinicians have suggested using blood smears to confirm infection. However, Telford and colleagues demonstrate that microscopy is not a reliable diagnostic method.
Blood smear examination is commonly used to detect parasites such as malaria and Babesia. These organisms infect red blood cells and are present at high levels, making them visible under a microscope.
In contrast, Borrelia miyamotoi is a spirochete that circulates in the bloodstream at low levels and does not produce easily visible structures.
Study Design and Methodology
Researchers evaluated blood samples from 20 patients with PCR-confirmed Borrelia miyamotoi infection.
Using standard thick smear techniques, they examined 100 microscopic fields per sample—already a sensitive approach designed to detect low-density infections.
Results: Extremely Low Detection Rate
No Borrelia miyamotoi organisms were detected in any of the 20 patients using standard examination.
When researchers extended the analysis to 300 fields per sample—three times the usual effort—they identified organisms in only 2 patients.
This represents a detection rate of just 10%, and only under conditions far beyond routine clinical practice.
Why Microscopy Falls Short
The failure of blood smears reflects key biological differences between spirochetes and parasites.
- Babesia and malaria infect red blood cells and reach high concentrations
- Borrelia miyamotoi circulates freely in plasma at low levels
- Spirochetes are thin, mobile, and lack distinctive structures
Standard microscopy simply does not have the sensitivity to detect low-level spirochetemia.
Recommended Testing
The CDC recommends PCR and antibody-based testing.
PCR detects bacterial DNA directly in blood, while antibody testing measures the immune response.
Both methods have limitations, but they are far more sensitive than blood smear testing.
For more on diagnostic challenges, see diagnosing Borrelia miyamotoi and Lyme disease testing limitations.
Clinical Implications
Blood smears should not be used to rule out Borrelia miyamotoi infection.
Patients with compatible symptoms and tick exposure may still require evaluation and treatment even when smear results are negative.
Clinical Takeaway
Blood smears miss most Borrelia miyamotoi infections. Use PCR or antibody testing instead.
Related Reading
- Lyme Disease Testing and Diagnosis
- Understanding Lyme Disease Test Accuracy
- Borrelia miyamotoi: What Lyme Patients Need to Know
- Doctors Face Challenges in Diagnosing Borrelia miyamotoi
- DNA Sequence Testing for Borrelia Infections
- C6 Peptide Test and Borrelia miyamotoi
- Antibiotic Treatment for Borrelia miyamotoi
References
- Telford SR 3rd, Goethert HK, Molloy PJ, Berardi V. Blood smears have poor sensitivity for confirming Borrelia miyamotoi disease. J Clin Microbiol. 2019.
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
Did they wait for how many hours, rechecking the findings hourly?
Those kind of spirochaetes bore themselves easily into the red blood cells as well as white blood cells. They dive to other tissues as well, particularly to bloodless ones. Like intervertebral discs, other joints, ligaments and tendons. It may take anything from 2-12 hours to see these bacteria coming out of those cells. That is when they can be seen moving in the plasma.
I summarized the frustration by the authors when testing for Borrelia miyamotoi. Hopefully your suggestion or others will lead to better tests.
Has anyone had testing for Lyme disease through urine . Ceres Urine Antigen?
My husband has been blood tested for Lyme, nope doesn’t have it. What he does have is severe abdominal pain that radiates and spends his life with the need to have a bowel movement. He is now on 2 Morphine’s , that do nothing really for the intense undiagnosed pain! He had to retire 3 years ago because he’s so ill. My son found this blog and the urine testing.
After spending all day in ER and once again checking with CT scans and bloodwork, pancreas, liver, gallbladder etc , all perfect, we need to find his problem. I think it’s Lyme disease. He’s was an avid bow hunter, always in the woods or outdoors, a tick magnet too. Walk out the door and BAM! He didn’t have to be in the woods or grass , just outside. Had the series of 3 vaccines to prevent Lyme disease when it came out in the 90’s. We live in VA, now deemed high in tick and Lyme’s.
Any help as to where to start?
I have not used the urine tests. I can not evaluate their reliability.
To Joyce Mahon – Both my husband and myself became ill with what was first diagnosed as Lymes disease. However my husband deteriorated rapidly until he put in the hospital with “diagnosis unknown”. He also most died before an excellent Infectious disease MD did blood slides and other test and discovered he had both Babesiosis & Ehrlichiosis and he was finally treated effectively, literally saving his life. Several years later I became very sick with high fevers and joint pain all over my body. I was taken to the hospital and admitted as a “toxic” patient as they could not diagnosis what I had. It was definitely not Lymes disease. Again it was finally diagnosed by an infectious disease MD as Borrelia Miyamotoi and treated appropriately and recovered. Again I am sick and the ER only checks for Lymes and tells me there is nothing wrong. So I now have an appointment with a top infectious disease specialist this week hoping it will be diagnosed properly. Please know that most ERs and physicians do not not test for these diseases and you must find a specialist who will. I urge you to do so as these diseases can leave lasting damage and potentially can be fatal.
I live on a dirt road surrounded by woods in NJ with lots of deer and other wildlife and there is little I can do about the ticks even though I use tick spray on myself and have my property sprayed several times each year. Good luck and best wishes. .
Where were you able to get blood slides. I am sure I have tick borne disease and I am near death.