Blood smear not reliable in diagnosing Borrelia miyamotoi disease

microscope, lab

Borrelia miyamotoi disease (BMD) is another tick-borne pathogen that can be difficult to diagnose with serologic tests. BMD is a spiral-shaped bacteria that is closely related to the bacteria that causes tick-borne relapsing fever.


Some doctors have suggested that a blood smear should be used to confirm the diagnosis of BMD. But as Telford and colleagues demonstrate, a blood smear may not be so reliable. [1]

In an effort to determine whether blood smears can detect B. miyamotoi in the blood of acute BMD patients, researchers examined sera from 20 patients, who were positive for BMD by PCR testing.

The authors “looked for evidence of BMD using standard malariological thick smears from anticoagulated blood samples.”

But after examining 100 thick smear fields in 20 patient samples, the authors could not find evidence of BMD in any of the patients.

Blood smears have poor sensitivity for confirming Borrelia miyamotoi disease. Click To Tweet

They were, however, able to find evidence of BMD in 2 of the 20 patient samples after examining 300 thick smear fields.

The authors conclude, “microscopy of blood smears is not sensitive enough for confirming a diagnosis of BMD.”

The Centers for Disease Control and Prevention (CDC) continues to recommend using PCR and antibody-based tests to confirm a diagnose of B. miyamotoi.

Editor’s note: I am not sure how sensitive the PCR and antibody tests are for BMD.

  1. Telford SR, 3rd, Goethert HK, Molloy PJ, Berardi V. Blood smears have poor sensitivity for confirming Borrelia miyamotoi disease. J Clin Microbiol. 2019.
Latest From the Lyme Disease Science Blog

Be Part Of The Conversation

3 Comment threads
2 Thread replies
Most reacted comment
Hottest comment thread
4 Comment authors
Gillian McAllisterDr. Daniel CameronJoyce MahonJarkko Kause Recent comment authors
newest oldest most voted
Notify of
Gillian McAllister
Gillian McAllister

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… Read more »

Joyce Mahon
Joyce Mahon

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,… Read more »

Jarkko Kause
Jarkko Kause

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.