What you need to know about Borrelia mayonii
In 2013, scientists at the Mayo Clinic noticed an unusual result while testing blood from patients suspected of having Lyme disease. Cooperation between Mayo Clinic, state public health agencies, and CDC confirmed the discovery as a new bacterial species, also found in blacklegged ticks. Joint efforts between these groups are currently underway to find more patients infected with this bacteria, to look for additional areas where infected ticks live, and to identify other bacteria that cause tickborne disease.
What is Borrelia mayonii?
Borrelia mayonii is the proposed name for a new bacteria species recently found to cause Lyme disease in six people who live in the upper Midwestern United States. Worldwide, Lyme disease is caused by three main species of bacteria: Borrelia burgdorferi, B. afzelii, and B. garinii. Borrelia burgdorferi causes Lyme disease in the United States, while the other two species are the leading causes of Lyme disease in Europe and Asia. Borrelia mayonii is a new species that is genetically distinct from these three species and is the only species besides B. burgdorferi shown to cause Lyme disease in North America. Regardless of the bacteria’s species, the illness is still called Lyme disease or Lyme borreliosis.
How was it discovered?
The new bacteria species was first identified at the Mayo Clinic in Rochester, Minnesota, where diagnostic samples from patients were tested for evidence of Lyme disease using a well-described polymerase chain reaction (PCR) assay. From 2012 through 2014, six of approximately 9,000 diagnostic samples from residents of Minnesota, Wisconsin, and North Dakota revealed the presence of a genetically distinct bacteria. Scientists analyzed the DNA sequences of these bacteria and found that they belonged to a new species of Borrelia. Blood from two of the patients was also tested by culture at CDC, and the organism was successfully grown in the laboratory.
Where does B. mayonii occur?
Current evidence suggests that B. mayonii is only found in the upper Midwestern United States. The new species was not identified in any of approximately 25,000 samples submitted from patients living in 43 other states, including states in the Northeast and Mid-Atlantic region where Lyme disease is common.
Has B. mayonii been found in ticks?
Yes. B. mayonii has been identified in blacklegged (or “deer”) ticks collected in several counties in northwestern Wisconsin and Minnesota. It is highly likely, however, that infected ticks occur in other areas of both states. The black-legged tick (Ixodes scapularis) also transmits B. burgdorferi, the agents that cause anaplasmosis and babesiosis, and Powassan virus.
What type of illness does B. mayonii cause?
Limited information from the first six patients suggests that illness caused by B. mayonii is similar to that caused by B. burgdorferi, but with a few possible differences. Like B. burgdorferi, B. mayonii causes fever, headache, rash, and neck pain in the early stages of infection (days after exposure) and arthritis in later stages of infection (weeks after exposure). Unlike B. burgdorferi however, B. mayonii appears to be associated with nausea and vomiting, diffuse rashes, and a higher concentration of bacteria in the blood.
What tests are used to diagnose B. mayonii?
Lyme disease, including infection with B. mayonii, can be treated based on signs and symptoms and a history of possible exposure to ticks. Currently available information suggests that patients with B. mayonii infection develop a serologic response similar to that of patients infected with B. burgdorferi. Therefore, Lyme disease two-tier testing can be helpful for detecting infection with B. mayonii if used correctly and performed with FDA cleared tests. In some instances, B. mayonii spirochetes may also be seen on a blood smear. At this time, infection with B. mayonii can be specifically identified by Lyme disease PCR tests at Mayo Clinic.
How is B. mayonii treated?
Physicians have successfully treated patients infected with B. mayonii with a 2-4 week course of doxycycline. Amoxicillin, ceftriaxone, and cefuroxime have also been used.
Why are we just discovering this now?
Good question! The diagnostic laboratory at Mayo Clinic has tested approximately 100,000 patient samples in the same way for over a decade but only recently detected evidence of B. mayonii. It is possible that the bacteria recently emerged or that the bacteria has been present in the area for a long time but at levels so low it escaped detection.
I live in the northeastern United States where Lyme disease is common. Should I be worried about B. mayonii?
At this time there is no evidence that B. mayonii is present outside of the Upper Midwest. However, you should continue to take precautions against tick bites as Lyme disease, anaplasmosis, and babesiosis are well established in much of the Northeast.
What more do researchers need to know?
CDC has initiated a project to detect and characterize the species of bacteria in specimens from patients suspected of tickborne illness like Lyme disease. Over the next several years, scientists aim to test 30,000 patient samples to gain more information about the extent and clinical course of this illness.
In addition, entomologists will continue to sample ticks in the Upper Midwest to determine the geographic extent of the ticks that are infected with this bacteria. CDC and the state of Minnesota recently completed a field collection of ticks from 80 sites throughout Minnesota. Ticks will be screened for B. mayonii to determine how geographically widespread and how prevalent the pathogen is in that state. Researchers also plan to test for B. mayonii in ticks that have been collected from other parts of the country.
How can I avoid this disease?
People living in areas where blacklegged ticks are common should continue to take precautions against tick bites and see their physician if they experience fever, rash, or malaise after a tick bite or after spending time in tick habitat. Click here for more information.