Easily solved.
Replace the waterboys (and girls) with alcohol based hand cleaner* boys (and girls). As soon as somebody starts looking a bit dodgy, rush out with a bottle of hand cleaner and maybe a bog roll.
Apparently, hand cleaner and bog rolls can stop the virus.
* hand cleaner is alcohol based not the boys (and girls)... then again, I think the egurls will do it the other way around.