Re: Rockwell: Read his paper, then got giardia in the Sierra
- Thank you John, I appreciate that. Thanks also to Roleigh and the rest of the group for the warm welcome and for taking the time to consider the points I made. Happy hiking all!
--- In firstname.lastname@example.org, John Ladd <johnladd@...> wrote:
> Thanks for the detailed posting, detailing the case that giardia remains
> enough of a concern to justify routine water treatment in the Sierra. I
> have added a link to the longer blogspot article to the Group's Links area
> (together with Rockwell's contrary argument).
> Readers interested in the issue could look at our Water Safety links area.
> It has a great deal of information, including information on water quality
> in Sierra lakes.
> John Curran Ladd
> 1616 Castro Street
> San Francisco, CA 94114-3707
- Buck, thanks for your dissection of this Faux News-type article or fable. It strikes me as beyond sad and counterproductive that "real" science is discounted in favor or opinions and random statements.
In another, more recent, post, I mentioned that I believe that Rockwell encourages Sierra (and other) hikers to act as unwitting carriers for distributing bugs to all. It's possible to have giardias and other amoebas in your system and not have debilitating symptoms - so, one believes that water treatment is unnecessary. And, spread the bugs to other drainages.
One quick note - also take care with supposedly clean water from developed springs. While hiking the Lost Coast, we treated all water. A storm swooped in and we stayed at an outfitter bungalow and drank the water without treating it. Not smart or good. I ended up with a horrible case of water-borne gastro-distress. It eliminated my hiking for nearly two weeks. The water was from a "tested pure" (haw!) spring. That's how come those Sawyer and other systems have that faucet attachment.
(Sorry for the late post - I've been hiking the Utah Flats-Phantom Creek area of The Grand Canyon, where we saw no other hikers for 5 full days. Yippee.)
take care out there, Rob of the WV
--- In email@example.com, "Buck" <alaskabuck@...> wrote:
> Firstly, I don't care if anyone chooses to not treat water. I do care about the underlying science though.
> Rockwell actually had me convinced despite two prior episodes of giardiasis I had years ago. I didn't treat most water in the Sierra when hiking the PCT, got really sick, and struggled to Mammoth where I was diagnosed with giardiasis. Again.
> I've since studied Rockwell's paper extensively and it is deeply flawed. (And it's NOT a peer-reviewed scientific paper.)
> 1. Rockwell compares the frequency of giardiasis to that of "shark attack." Hardly. It's still so common it's referred to as "the backpacker's disease." "Several backpackers appear weekly at Centinela Mammoth Hospital in Mammoth Lakes sick enough with giardiasis to need urgent care," said Dr. Jack Bertman, an emergency physician. (LA TIMES.) Note, that's an old article. Coincidentally, I was treated at the same hospital for giardiasis in 2010 and my Dr. had a very similar quote.
> 2. Rockwell says Sierra water is cleaner than SF water. Untrue. SF water is treated with UV, Chlorine and Chloramine and is thousands of times safer from giardia.
> 3. Rockwell says there's too little giardia in Sierra water to make you sick. Sometimes, but often there's plenty. Rockwell says you only need 10 cysts to get sick but the best science estimates that there is a 2% chance of contracting giardia with a single cyst. The largest, most recent Sierra water survey that I've seen was summed up like this "Nowhere is the water dirtier, he [Derlet] discovered, than on U.S. Forest Service land, including wilderness areas, where beef cattle and commercial pack stock horses and mules graze during the summer. There, bacterial contamination was easily high enough to sicken hikers with Giardia, E. coli and other diseases." Derlet also found pathogens in pristine areas without livestock.
> 4. Rockwell says hygiene is what's important, while water treatment plays a minimal role. His claim is speculative. The only study I've been able to find (this one dealing with the Appalachian Trail)that compares the two with DATA says water treatment is even more important. "CONCLUSION: Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water. The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware." http://www.ncbi.nlm.nih.gov/pubmed/12681456 It's a moot point anyway to me, because BOTH are clearly important.
> 5. Rockwell says the medical literature does not support the widely held perception that giardiasis is a significant risk to backpackers in the United States. False. There are many peer-reviewed scientific papers that link giardiasis and other waterborne diseases to drinking untreated back-country water. The CDC, EPA, FDA, Mayo Clinic, and all public health organizations who have taken a stand, to the best of my knowledge, disagree with Rockwell. The overwhelming majority of the "scientific" claims that there is little if any risk from untreated backcountry water lead back just two authors, Rockwell and Welch. Neither have degrees in microbiology. That doesn't make them wrong, but their bad science does.
> Check out this link for my cited sources: http://bucktrack.blogspot.com/search?q=giardia
> Again, I don't care if people treat their water, and many people go for years without getting sick from not treating water. But many people are not so fortunate.