Yep, if you are unlucky, the ticks can cause viruses. My mom got Borrelia when she was young but fortunately in a very light form.
A good precaution is to have someone have a good look at you just like a good antivirus program.
...and never try to pull them out with force! You can kill the process of being harassed by removing them using butter in combination with a Tick Twister like this one: