Sampling bias of being around literal assholes all the time, for one. Second, nearly every animal not being or under the care of a human has parasitic whatevers. Not a question of if they have them, but what kind.

For them, they probably do. The nurse said that their job included it, and most healthcare people who are having to go hands-on with a patient for cleaning purposes aren't doing it for fun, but because the person needed it.

You don't travel to third world countries to eat rural villager ass?