[pct-l] Filter vs Purifier

[Bruce 'Buck' Nelson]

The largest retrospective scientific study ever done
(http://www.journals.elsevierhealth.com/medline/record/ivp_00029262_105_330%20)
 on backcountry giardia concluded this: "drinking untreated mountain
water is an important cause of endemic [giardia] infection."

The only study that I can find that actually compares hygiene and water
treatment behaviors DIRECTLY with DATA found that water treatment is MORE
important to backcountry health. It's a false choice anyway, because
they're both important.

http://www.amjmed.com/article/S0002-9343%2802%2901494-8/abstract
"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."

Beyond a reasonable doubt, I got giardia from drinking water in the Sierra.
I was almost exclusively hiking alone, not sharing trail food, using hand
sanitizer and drinking untreated water.

The CDC has more data than anyone. They base the following risk factors
(along with child care settings etc.) on DATA, what happens in the real
world: "Anyone may become infected with *Giardia*. However, those at
greatest risk are"...


   - Those who are in close contact with someone who has the disease
   - People who swallow contaminated drinking water
   - Backpackers or campers who drink untreated water from lakes or
   rivers...

http://origin.glb.cdc.gov/parasites/giardia/epi.html