It's carried by ticks, has been around for several decades and is often times misdiagnosed as the flu.
The other, lesser known tick-borne disease called anaplasmosis is yet another thing to worry about this tick season.
Last November, Kathy Grenier was bit by a tick, and what followed was a medical odyssey that's left her with lingering symptoms and a better understanding that there's more to tick-borne illnesses than Lyme disease.
"I actually thought I was going to die," said Grenier. "And I would never have thought that one little tick could have taken me down."
A few weeks after being bitten by that little tick, Grenier developed fever, chills and a bad headache.
"I had called the doctor to say, 'ya know, I don't know what's going on' and they said 'yeah, you have a bad case of the flu.'"
Eventually, those symptoms eased, but then came back around Christmas, this time so bad that Grenier was admitted to the hospital.
Grenier underwent more than 100 tests to rule out other illnesses, and then, almost by chance, she happened to mention to one of her doctors that a month earlier she had been bitten by a tick.
At that point in time, Kathy's arms were bruised purple from all the testing. Finally, doctors drew a sample which tested postive for anaplasmosis.
"Anaplasmosis is a bacterial infection that is transmitted by a small tick -- the same tick that transmits Lyme Disease," said Mark Klempner, MD, a professor at UMass Medical School.
Dr. Klempner says that, unlike Lyme disease, anaplasmosis usually doesn't cause a rash, and it can be serious.
"When you wait, people can get very sick - and there are people who actually die from anaplasmosis," said Dr. Klempner.
After spending more than a week in the hospital, and undergoing weeks of antibiotic therapy, Grenier recovered and is now sending a message to others.
"I think everybody's more worried about Lyme Disease, but after having anaplasmosis, people need to educate themselves more," said Grenier.
Cox Media Group