i normally treat water with iodine when downstream from civilization but not always. out on the john muir i did not treat at all. i am 69 yrs. old. when i was a lad and working with my dad in the summertime on const. we took our lunch in a paper sack with left over chicken, minced ham sandwiches, potato salad etc. was no such thing as ins. cont. with ice. never once got sick. i think we became resistant to the bugs. and probably still are. but the younger generation are probably not as resistant now a days.
pa kettle