Toxic shock syndrome is a very serious life threatening syndrome that is caused by a toxin made by a bacteria. The bacteria in question (staphylococus) was associated with super absorbent tampons. These bacteria were found to be growing behind these tampons. The toxin causes the immune system to become activated and the blood vessels to dilate. This can cause blood pressure to drop which can be fatal.
The culprit tampons were taken off the market back in the 80s. Now toxic shock syndrome secondary to tampon use is very low and should not be considered significant enough to sway you away from using them. The chances of you getting it is probably on the order of 3 in 100,000. You are much more likely to be killed in a car accident.
Your OBGYN will discuss this with you if you bring it up. Otherwise it is not a useful thing to discuss with your doctor
as your time with him or her is often limited and can be used in better ways. I suggest that you take a look at the type of tampon you are using and see if there is any reports of toxic shock syndrome risk with that tampon. I think that you will find that you are safe enough from this fearsome condition.