Generally speaking the cure is a proactive and pre-emptive one.
Vitamins, electrolytes, eating well, and washing your hands regularly. Sleeping properly helps too, but that one's a bit harder than the rest during Fanfest at least.
I appear to have dodged it entirely this year which is awesome. I could use not having to deal with that shit on top of everything else on my plate at home that I didn't get a chance to process or deal with before I had to leave for Iceland.