[ajuc]

Yes, bąblowiec, I'm well aware. My sister is a vet. We always wash the blueberries after gathering because of that (and preferably you should gather berries after a strong rain). Also cooking the berries (like in the case of pierogi) might not help but I think usually will kill them? I've seen different opinions (even among doctors).

You can also get slightly different version of bąblowiec from dogs, and dogs touch EVERYTHING when they go on a walk, so basically if you're afraid about that you should deparasitize (is that a word in English?) the dog every year if you take your dogs for walks in nature (or visit places where lots of dogs poop - like dog parks).

In the end it's not that common (I mean it's common among foxes but not common among people - there's like few dozen cases a year in Poland AFAIR). Probably many more causes are never recognized because it develops very slowly but still - if it was easy to catch people would talk about it constantly.