What about portages?  It is summer and you are wearing sandles.  On a lot of portages you are going to be getting your feet wet and some of that water is going to be swamp water or worse.  At the end of the portage you adjust your sandles or socks and horrors of horrors your hands touch the dirty water.  Do you immediately wash your hands or just wipe your hands on your pants.  You are going to be exposed to germs regardless of how careful you are.  How many campers eat food which has fallen on the ground even if the 5 seconds rule is violated.  Everyone is comfortable with a certain level of exposure to risks.  My attitude is not to let unreasonable fears lessen the enjoyment of my trip.
Westwood