Quick reading says Nitrofurazone [ API Furan 2] with Rid ich [ not the herbal crap] or ich med with malachite green and formalin is the recommended treatment.
I read several links and liked this one ;
https://www.aquarium-pond-answers.co...erebralis.html
Being you have wild fish it is very possible if you kill the the parasite your issue may end like that ..It takes two host for the parasite to reproduce so once gone it should not come back . That is going under the belief is the fish came infected ?