Rat lungworm has a ground zero, Puna.

[My 2 cents]

A friend of mine is a terrific gardener. He has been eating vegies from his garden and greenhouse almost daily for over 30 years. He does see the slugs around, sometimes even in his greenhouse. Of course he washes, etc., but that's a lot of potential exposure. He thinks that perhaps over time he has built up a resistance or even immunity. I never heard this suggested before. Could this be possible?