Deer ticks in Wisconsin and Minnesota are carriers of a newly discovered strain of bacteria. Photo: Stuart Meek
Researchers have discovered a new strain of tick-borne bacteria in two Great Lakes states.
The germs were discovered in infected people and deer ticks in Minnesota and Wisconsin. They cause ehrlichiosis in humans, a disease that causes headaches, muscle aches and fatigue. If left untreated kidney, lung and brain function can be damaged.
“Ehrlichiosis in humans was rare in these states,” said Dr. Bobbi Pritt, co-author and microbiologist with the Mayo Clinic. “It wasn’t on the radar of physicians and health departments.”
The symptoms of ehrlichiosis are hard to distinguish from other infections, said Susan Paskewitz, co-author and professor of entomology at the University of Wisconsin.
“We had a person in our department (of entomology) who thought he had Lyme disease,” Paskewitz said. “They took him off of antibiotics and everything … these things can persist a long time if untreated.”
The research began after a “savvy technician” at the Mayo Clinic was examining a patient’s DNA and found it acting abnormally, according to Paskewitz. The Center for Disease Control, universities and health departments then began studying it.
Researchers have screened thousands of blood samples from around the country and have found 35 infected people, Pritt said. All cases are believed to have their origins in Minnesota and Wisconsin.
Researchers also tested thousands of ticks and the bacteria were only found in deer ticks in the two states.
It is unknown why the bacteria have been confined to the two Great Lakes states, especially since there is a high deer tick population on the east coast, according to Paskewitz.
However, the ticks and bacteria could spread.
“It certainly may pop up in other parts of the country,” Pritt said. “It’s possible that (the bacteria strain) was here for quite some time, and just now we have the tools to pick it up.”
As state and local health departments have been involved in the research since the beginning, they are now testing patients who have ehrlichiosis symptoms for the new bacteria.
According to the University of Rhode Island, deer ticks are approximately the size of a sesame seed and found primarily from September through November. Humans are most likely to be bitten and infected during summer months.
Deer ticks are most notorious for carrying Lyme disease. Lyme disease has similar symptoms to ehrlichiosis.
It is still unknown which animals can carry the new bacteria.
“With Lyme disease, deer and small rodents are carriers. So far we’ve found it in one mouse in Minnesota and one in Wisconsin,” Pritt said.
In addition to further animal testing, the team is researching the bacteria’s geographic spread and its life cycle, Pritt said
The Minnesota Department of Natural Resources recommends wearing protective clothing and using insect repellant while in the woods, and then washing clothes and showering afterwards. Deer ticks are most common in hardwood forests and brushy areas.
The risk of getting a tick-borne disease is small if the tick is removed soon after it becomes attached. Deer ticks must remain attached for approximately 24 hours to infect their host.
The tiny pests are hard to see, and symptoms can be benign, so it’s best to stay alert, Paskewitz said.
“Many people aren’t aware that they’ve been exposed to ticks. They’re very easy to miss.”