I don't know if this might unbalance things, (and I know this is the wrong section for this) but it might be worth considering having a Pharmacist, Chemist or Doctor profession in the game where NPCs can be sent to have diseases removed. Maybe other things too like Botox to give a temporary boost to body part stat.
Yeah an STD clinic/profession has been discussed and requested before. Getting medicine is pretty random.
Prevention is a good strategy, stocking up ahead of time and always testing new actors and your own after they been away with someone else.