Interesting. The survey was based on a postcard mailed by Appalachian Trail hikers doing at least 7 days on trail. Of the 300+ people who agreed to participate, 18 were disqualified due to having no permanent mailing address.

I know these kind of guys (and gals) very well, and in fact I got Giardia on the AT myself last year. Or something like giardia. The fact is, I don't know, I was getting over symptoms by the time I saw a doctor and so was never tested. I think *that* might be all too common, along with an inclination to state definitively what caused the problem, regardless of whatever underlying data is known (or not really known).

The fact is that few people really know where they got "it" from, whatever it is. And "it" hits different people in quite different ways. I ran into a guy in NM on the CDT this year who was taken by ambulance to get fluids pumped into him because he was so dehydrated due to diarrhea, yet just a couple of days later he was strong enough to get back on trail hiking again. My own experience was that it took me over two weeks before I had enough strength to get back on trail, well after (other) symptoms were gone.

My strongest personal conclusion on all of this is that it's too easy to form questionable conclusions. I certainly was more careful in treating my water this year, yet I still didn't always treat, and I didn't get sick, or even have any mild discomfort. I'm normally careful in after-toilet hand cleaning, but there was a goodly chunk of time after I lost my hand sanitizer gel mid-trip this year that I wasn't able to do so.

I've talked directly to quite a number of thru-hikers who have had "giardia" or something at least messing with their guts, and I think that the human tendency to find patterns and form conclusions can often trick us.

Certainly it's hard to argue with the conclusions that it's good to wash up after using the toilet, it's good to wash dishes well (if you must use 'dishes' ...), and it's good to somehow treat your water in at least many/most cases. The aggregate of those things, practiced by not only myself but those who I come into contact with, should indeed reduce my chances of getting ill.

I have a hard time accepting any sort of more specific conclusions than that, however.

Oh, wait, cattle --- nasty beasts, double treat if cattle have access to the water source. Or if there are dead animals in the water. And I learned this year to not assume that a pipe coming a long way from a spring necessarily means that the spring itself is fenced off from cow access. I'll accept those as 'conclusions' with no problem!