It is untrue that elves can’t get sick. There are illnesses that affect elves, mostly due to malnutrition, climate, toxins or other outside influences that have compromised the immune system. They can also get sick from bad digestion, substance abuse, and eating too much. There are also immunodeficiency disorders that give them a more human level of immunity. And while they may not suffer the outward affects of STD’s, they can still be carriers, making the whole “if we have elven whores in our brothels then they won’t spread disease” philosophy a bunch a shit.