It is distressing, however, until you can be sure that everyone who has recently used a rest-room also washed their hands - I suggest you carry sani-wipes or a germicidal gel.
You may have OCD (obsessive compulsive disorder).
I was raised on a farm and believe me, I and my siblings ate and touched everything that was exposed to chickens, geese,cats, dogs, pigs, goats, cows, horses and the hired hands. A tooth pick would have been considered gentile. We were quite healthy.
As opposed to Kosher?