Ok, during the last couple of sessions the PCs had been hammered pretty hard by their opposition. One PC started the last game at 3 HP and had already had First Aid done on him (he was in the negatives prior to the Heal check). One of my other players had the Stygia book on him and suggested going to the Mitraeum to see if anyone there could perform the Surgery skill. I didn't see a problem with this so allowed it. However, the first roll was a fail and the skill says that this causes disease. My question is, what diseases and what are the effects of those diseases? Where in the books can I find this information?