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CDC's tick advice remains the same after Lyme disease discovery

Jul 6, 2017

There’s a newly discovered kind of bacteria that can cause Lyme disease, Borrelia mayonii. Scientists have run tests to find out how long it takes to transmit the disease after a tick bites you.

Before the new bacterium was described last year, scientists thought there was just one kind of bacteria that caused Lyme disease in the U.S. (it's called Borrelia burgdorferi).

Lars Eisen is a research entomologist with the Centers for Disease Control and Prevention, and the senior author of a new study in the Journal of Medical Entomology.

He says there are other closely-related bacteria that cause the disease worldwide.

“So it was not terribly surprising that we discovered a second one in the United States that also causes Lyme disease here,” he says.

Eisen says earlier studies of B. burgdorferi showed that the risk of Lyme disease increases the longer a tick is attached to a person or animal, which is why daily tick checks are a standard recommendation for preventing Lyme disease.

“So what we wanted to do in this new study was to confirm that this new bacterium causing Lyme disease behaved in a similar way,” says Eisen. “And we saw the same thing as we had seen previously for Borrelia burgdorferi. We did not see any transmission by a single infected tick in the first 24 hours of the tick being attached, but then as the days progressed, the risk of transmission increases day by day.”

He says CDC's advice remains the same: carefully check yourself and your kids for ticks every day, and quickly remove any ticks you find.

Kate Fowlie, a CDC spokeswoman, added by email that the general guidelines for tickborne disease prevention have not changed, and that physicians in the Upper Midwest should be aware of specific tickborne diseases in their area:

In light of these new findings, we encourage health care providers in the Upper Midwest to consider B. mayonii infection in patients with compatible signs and symptoms – fever, rash, headache, neck pain, nausea, vomiting, or joint pain – and a history of possible recent exposure to ticks.

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.

She says Lyme disease caused by B. mayonii has been successfully treated with antibiotics. More information about B. mayonii can be found on the CDC website.