This should probably be in the design forum...
I don't think it would be too hard. Maybe the type of disease could be determined by sector type when the player contracted it or a random roll or both.
Maybe similar to introducing yourself, if you are in the same room with another player for a minute or so while you have the disease then a roll is is made against the players CON. If it fails, they get sick. Maybe a roll against the players Empathy to see if the player notices they are sick (or the type of disease if not shown in score).
The healer could either heal all sorts of disease with "heal disease" or "heal flu" "heal pnemonia" etc.. If you have specific heals for each type of disease, then the heal that fixes them all should cost more. Class skills could be created to detect disease and cure disease.
In class edit there are poses, which make the class do certian emotes every once in awhile, maybe if the person is flagged sickly, they could sneeze, scratch, break into hives etc. according to the specific disease.
As an ooc joke, you could check to see if the player is in the addict slot, if so have the player catch "addicted" which would be like insomnia so they don't need to sleep or something.
- Cry in the Dojo, Laugh on the Battlefield -