It's worth noting that illnesses seem to be well under control. Aside from the Tonberries (and their illness is a very special case), there doesn't seem to be any kind of quarantine areas, like leper colonies or whatever. In fact, illnesses in general are rarely mentioned; I'm sure someone in game must have a tragic backstory of losing one or both parents to illness, but off the top of my head I can't remember any. Magic and/or magitek seem to be VERY effective at keeping sickness at bay - possibly even better than real life medical science is capable of.

Quote Originally Posted by Enkidoh View Post
To be really fair, native Eorzean medical knowledge appears to be somewhat rooted at a medieval level, with a solid belief in long-abandoned archaic theories such as body humours. Not to mention a lot of medical treatment is purely magical, using conjury and arcanima to heal wounds and disease (and by extension, white magic and scholary magic). Then there is alchemy for healing which is another branch of medicine which is perhaps closer to actual scientific principles of chemistry (as it was in the real world), but still with a esoteric bent.
Just to toss in the standard disclaimer, just because medical knowledge involves theories long abandoned in real life, does not mean those theories are WRONG. This is a fantasy universe, and stuff like the theory of body humours might actually be true.