If the kittens starts to fade, brew up some strong coffee, make sure it is at room temperature and place just a few dropfuls in the kitten's mouth. Wrap the kitten up in a warmed towel and begin to rub gently, much like you would a baby trying to get them dry. Not patting, but rubbing with just a bit of stimulation to jumpstart the heart. Hopefully, you won't have to go to this method, but it is one that I have used for years told to me by a wonderful vet- and it works if it is the heart that is the issue.
Kittens can catch anything that Mom has in-utero, I do not know much about tick disease. The only thing we have here is Lyme disease which is pretty nasty for humans and animals alike. but it is possible this little kitten is suffering from much the same affliction that got mom.
Good luck-