Repost of Bob R's article:

http://pweb.jps.net/~prichins/giardia.htm

Good personal hygiene is super important. Yes, wash your hands thoroughly after making your personal wag bag contribution...and before food preparation. Many more people have become sick through poor hygiene and contaminated cooking gear than from giardiasis.

Case in point: during our hiking trip in southern Ireland this past May, I came down with a case of campylobacter, which is cased by improper chicken preparation and cross-contamination in kitchens. It took me three weeks to completely recovery. So...be careful, be clean, drink the water.