Compact News: CDC Press Release: New Lyme-disease-causing bacteria species discovered

Monday, February 8, 2016

CDC Press Release: New Lyme-disease-causing bacteria species discovered

Press Release

Monday, February 8, 2016

Contact: CDC Media Relations

(404) 639-3286

New Lyme-disease-causing bacteria species discovered

Borrelia mayonii closely related to B. burgdorferi

The Centers for Disease Control and Prevention, in collaboration with Mayo Clinic and health officials from Minnesota, Wisconsin, and North Dakota, report the discovery of a new species of bacteria (Borrelia mayonii) that causes Lyme disease in people. Until now, Borrelia burgdorferi was the only species believed to cause Lyme disease in North America.

Scientists at the Mayo Clinic in Rochester, Minnesota, first suspected the possibility of new bacteria after lab tests from six people with suspected Lyme disease produced unusual results, according to the findings published today in Lancet Infectious Diseases. Additional genetic testing at the Mayo Clinic and CDC found that the bacteria, provisionally named Borrelia mayonii, is closely related to B. burgdorferi.

“This discovery adds another important piece of information to the complex picture of tickborne diseases in the United States,” said Dr. Jeannine Petersen, microbiologist at the Centers for Disease Control and Prevention.

So far, new Lyme species found only in upper Midwest

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 is associated with nausea and vomiting, diffuse rashes (rather than a single so-called “bull’s-eye” rash), and a higher concentration of bacteria in the blood.

The researchers believe that, like B. burgdorferi, B. mayonii is transmitted to humans by the bite of an infected blacklegged (or “deer”) tick. B. mayonii has been identified in blacklegged ticks collected in at least two counties in northwestern Wisconsin. The likely exposure sites for the patients described in Lancet Infectious Diseases are in north central Minnesota and western Wisconsin. It is highly likely, however, that infected ticks are found throughout both states.

The newly recognized species was discovered when six of approximately 9,000 samples drawn from residents of Minnesota, Wisconsin, and North Dakota with suspected Lyme disease between 2012 and 2014 were found to contain bacteria that were genetically distinct from B. burgdorferi. Scientists analyzed the DNA sequences of these bacteria and found that they belonged to a previously unrecognized Borrelia species. Blood from two of the patients was also tested by culture at CDC, whereby the organism is grown in the laboratory.

To date, the evidence suggests that the distribution of B. mayonii is limited to the upper midwestern United States. The new species was not identified in any of the approximately 25,000 blood samples from residents of 43 other states with suspected tickborne disease taken during the same period, including states in the Northeast and Mid-Atlantic region where Lyme disease is common.