» New Lyme disease source:

Species found in western Wisconsin, parts of Minnesota

Researchers discover a new species of bacteria in Wisconsin that causes Lyme disease.

Researchers have discovered a new species of bacteria in Wisconsin that causes Lyme disease, already the most frequently reported tickborne illness in the state.

Until the discovery, Borrelia burgdorferi was considered the only bacteria that caused Lyme disease in North America, which is passed to humans by a bite from the tiny deer tick.

The new bacteria has been named B. mayonii, a tip of the hat to the scientists at the Mayo Clinic in Rochester, Minn.

Mayo staff, according to an article published in Lancet Infectious Diseases, began to suspect the possibility of a new bacteria when, between 2012 and 2014, lab tests from six people they believed had Lyme disease yielded unexpected results.

Genetic testing by Mayo and the U.S. Centers for Disease Control and Prevention identified B. mayonii.

The bacteria is also transmitted to humans by deer ticks, but symptoms of infection are slightly different than those of the B. burgdorferi, according to the CDC.

In early stages of infection — days after exposure — both bacteria cause fever, headaches, rash and neck pain.

But the newly discovered bacteria does not cause Lyme disease’s signature bull’s-eye shaped rash. Rather, it is associated with nausea, vomiting and diffused rashes.

The likely exposure sites for the patients described in the Lancet article are north-central Minnesota and western Wisconsin, the CDC said, and infected ticks have been collected in at least two counties in northwestern Wisconsin.

“It is highly likely, however, that infected ticks are found throughout both states,” it said.

Scientist believe distribution of the newly discovered bacteria is limited to the upper Midwest.

People infected with the B. mayonii will test positive for Lyme disease with currently available tests, according to the CDC.

The six patients described in the Lancet article were successfully treated with antibiotics commonly used to treat Lyme disease caused by B. burgdorferi.

More than 23,000 cases of Lyme disease were reported in Wisconsin between 1980 and 2010, according to the state Department of Health Services.

Oral antibiotics effectively treat early stages of Lyme disease.

If left untreated, according to the DHS, complications such as meningitis, facial palsy, heart abnormalities and arthritis may occur. Swelling and pain in the large joints may recur over several months or years in untreated cases.