A twist of Lyme: New strain of Lyme disease discovered

The CDC, the Mayo Clinic, and Minnesota, Wisconsin, and North Dakota health officials have discovered a new species of bacterium that causes Lyme disease in people. Borrelia burgdorferi was the only bacterium believed to cause Lyme disease in North America, but the aptly named Borrelia mayonii has been found in – and so far confined to – the United States Upper Midwest (north central Minnesota, western Wisconsin, and North Dakota). “This discovery adds another important piece of information to the complex picture of tickborne diseases in the United States,” microbiologist at the Centers for Disease Control and Prevention Dr. Jeannine Petersen said. The findings were published in Lancet Infectious Diseases.

Mayo Clinic scientists in Rochester, Minnesota discovered the previously unknown bacterium when 6 of approximately 9,000 samples taken from Minnesota, Wisconsin, and North Dakota residents with suspected Lyme disease between 2012 and 2014 produced unusual tests results, prompting a DNA analysis that confirmed the new species belongs to the Borrelia genus. Conversely, about 25,000 blood samples collected from residents of 43 other states with suspected tick-borne disease during the same period showed no traces of B.mayonii. The new Lyme species is different yet similar to B. burgdorferi.

For example, researchers believe that both bacteria are transmitted to humans through the bite of an infected blacklegged tick – also known as deer tick. As a matter of fact, B. mayonii has been identified in blacklegged ticks collected in at least two counties in northwestern Wisconsin. Additionally, the two bacteria cause fever, headache, rash, and neck pain in early stages and arthritis in later stages. However, the two strains are genetically different, and B. mayonii, unlike  B. burgdorferi, has been linked to nausea and vomiting,  a higher concentration of bacteria in the blood, and diffuse rashes – as opposed to a single “bull’s eye” rash.

The patients who tested positive for B. mayonii-related Lyme disease – with current FDA-approved tests – were successfully treated with the same antibiotics used to treat B. burgdorferi-related Lyme disease. The CDC recommends healthcare provider to follow the Infectious Diseases Society of America’s antibiotic regimen when treating patients infected with B. mayonii. The health agency is collaborating with Minnesota, North Dakota, and Wisconsin state health departments in order to gain a better understanding of B. mayonii and plan future research, and better describe the clinical aspects of the illness and the geographic reach of the infected ticks.

“CDC is investing in advanced technology to bring study of tickborne infections into a new era,” chief of CDC’s Bacterial Diseases Branch Ben Beard, Ph.D. said. “Coupling technology with teamwork between federal, state, and private entities will help improve early and accurate diagnosis of tickborne diseases.” The CDC makes the following recommendations to lower the risk of tick bites and tick-borne disease:

·         Avoid wooded and brushy areas with high grass and leaf litter.

·         Use insect repellent when outdoors.

·         Use products that contain permethrin on clothing.

·         Bathe or shower immediately after coming indoors to wash off and more easily find ticks.

·         Conduct a full-body tick search after being outdoors.

·         Check gear and pets, as ticks can come into the home on these and later latch on to people.

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