As a physician, I agree that infection with giardia is inconvenient, but it is not really serious. Furthermore, this infection is over-diagnosed. By that I mean that a presumptive diagnosis may be made based on the history of being on high mountain streams, but if the actual causative organism (giardia lamblia) is not specifically identified (e.g., by examination of the stool under a microscope) then the presumptive diagnosis may be wrong, and the diarrhea may be caused by the one of the hundreds of other causes of diarrhea. I am particularly skeptical about the diagnosis if the subject has not actually drunk water from the stream. That is, putting wet tippet in your mouth is unlikely to cause exposure sufficient to cause clinical infection.
How real is the risk? Well, I drink water from most of the trout streams that I fish. The exception is if there are cattle grazing upstream.
Thanks Doc. The stool sample following treatment with Flagyl showed no Giardia. I did have a small mouth ulcer which may have been the source of the invasion. I also ate some Mexican food on my trip which might have been a problem but the symptoms occurred @ 6/7 days from the trip home from Bristol. As an aside there were otters near by which I believe may also be carriers. The medical treatment was also supplimented by 1000mg of Garlic .this was a recommendet treatment from internet. That alone will make me more cautious. Thanks for input.
Eight years ago we were on a trip to Sedona and were told there were possible problems with e coli in the stream, resulting from run off contaminated with mule deer and elk droppings (?). Then there is this http://www.pharmacynewsflash.com/vapharmacy/Story.nsp?story_id=162412279 - I dont think I will be drinking any water from the stream…