>>535847290
They do exist, you can just cast a spell to get rid of it though.

Clerics and wizards can make a very good living just hanging out in cities casting low and mid level spells to solve everyday problems for some gold, and that includes restoration and cure minor wounds and remove curse and the like.

Some diseases resist mundane magical cures, but those aren't the type you're going to pick up at a brothel. Well....usually.