My wife used to use needles, and share them. She has been clean from drugs for over 6 years. We have both been tested for everything several times since. Is there a chance of things 'popping up' years down the track? Is there a time that we can be deemed "safe"?
NO there is no time limit as to incubation. Even now when the medical fraternity hazard a guess, the do admit that they do not know. You will have seen the various times quoted for AIDS & CJD etc. This is something you will have to live with, and also your children - if you have the decency to tell them.
Without sounding doubtful, are you qualified to make an "informed" response? You seem to doubt the effectiveness of the medical profession. If you think you do, how do you know better than them? If it is some 'higher being' crap, please don't bother replying.