What Robin said.

At this point you don't even know that it was the snake you bought at the show if you have no diagnosis as to what was wrong with any of the three dead snakes. You did say it did not appear sick, which would make sense because I doubt anyone would buy a snake that looked sick.

Since you lost 3 snakes, of two vastly different species, I would look closer at your quarantine area. Is there any possibility of someone spraying something too close by(a neighbor spraying their lawn or bushes could cause a drift of pesticides/fungicides/etc)?

I don't understand how you losing one snake(then two others) equates "something going around the snake circuit". And not to beat you up, or imply anything, but nearly every person who posts about losing snakes, no matter how mundane the cause of death turns out to be, says things like "I've got lots of experience."

It's great to want to warn people of some sort of possible illness... but to imply that it's "going around" an entire state when you've got not even one other case outside your own quarantine, is not only stretching it, it's snapping it and flipping the pieces at breeders/dealers.