Swimmer's Itch Snails

[Kai]

Hi everyone, 
I've searched around for a bit and can't seem to find the information I'm looking for. I have a bunch of New Jersey caught snails in my 29 gallon and sump, the only things in it are snails, a couple grass shrimp, and a hermit crab, all Jersey caught. I have been told that they're mud snails, and they do look like the images I've found on google, and apparently mud snails can carry swimmer's itch. Whenever I stick my hand or arm in the tank, I get an itchy rash, but everyone in my house myself included, is having some major allergic reactions to the 50 year old carpeting that's on it's way out. On top of that my skin has always been pretty sensitive. So I don't know if it's just because I'm sticking my already itchy arms in saltwater or if it's actually a parasite or not, but to play it safe I'm operating under the assumption that it is for when I start stocking my tank.

Some of them wander around on rocks, or glass, or in the sand, some of them have a spot and have not moved. Maybe they're dead, I have no clue, I know some of them have died as I have found their lovely rotting stench while moving my sand to my final tank.  

What I need to know is if the snail is infected for it's entire life or if when what's in it comes out is it done? Or will it attach to any fish I get? So I know the parasite goes from the water into the snail, matures a bit, then leaves the snail looking for a host where it can burrow under a person's skin and cause a rash. So when that batch comes out of the snail, is that all? Is the snail done spitting that stuff out, or will new cycles continue in the snail until it ultimately dies? That free floating parasite that came out of the snail, if it's in the water can that infect a healthy snail since it's a different stage in the life cycle?

I need to know so I can either send the snails back to the ocean this weekend, or let them live to see another day in my tank.