Dawn
Fifth is very contagious, but I do not know for how long. However, I would not be around anyone with a suppressed immune system, as I do know it tends to flare back up after 2 weeks or so, and generally takes about 6 weeks to run its course. It would not be fair to risk the other person, as it could be far worse (as far as symptoms) for him/her than it was for you. If you must be around them, wear a mask to reduce exposure, and thoroughly wash your hands first.