Note: I altered the link, if you are logged in, you'll need to takes members/ out if you are publishing a link. It is set-up that way, so the two sides aren't completely separate, so as a member you are still logged in on the normal part. - paul
I think this problem is like the common cold. We've all been swapping and sending snails left, right and centre. I haven't for months now and my problems are subsiding. We keep our snails relatively safe from disease so they've never been weeded out or strengthened like in the wild. Everytime we get new snails, our old ones are at risk even with quarantine and careful hygiene. We couldn't maintain them in oxygen tents with radiation suits on. We inevitably pass things on ourselves. It is fairly random but so far it seems fulica, immaculata inc. dimidiata and panthera are affected. My other achatina and all my archachatina have been fine.
In my case, I had problems (and still have 1 not eating) that lasted a 3-4 months or so. I think whatever it was simply swept through and picked off the ones it was gonna do. I have 2 recovering dimidiata so it isn't all bad news. I'd like to think my remaining ones are fairly immune to it.
That's my current thoughts anyway, if anyone has more information I can add to the page, let me know.