[pct-l] Treating water

[CMountainDave at aol.com (CMountainDave@xxxxxxx)]

In a message dated 11/9/03 8:08:30 AM, conniedavis@earthlink.net writes:

<<  Drinking untreated water is like many of the other decisions we make on 
the trail, it's a calculated risk, and worth weighing the potential 
consequences.  >>

It boils down to whether or not you believe the medical experts when they say 
most people exposed to giardia cysts not only show no symptoms, but actually 
become immune. Some people exposed become ill, and never really recover. They 
become carriers of giardia and are suspected of being the ones who transmit 
the parasite to others via compromised hygiene and social contact. Some of these 
people become carriers and so on. 
   A very small minority become violently ill
  I have no doubt that giardia is present in nearly all water sources. But 
the concentration is so low that non immune people would have to drink very 
large quantities of water to reach the level of exposure necessary to make giardia 
possible
   The mystery, of course is that, given the same level of exposure, some 
people get ill while a vast majority don't. But then some people have an allergic 
reaction to bees and peanuts while most don't
  If some people get ill from eating peanuts, does it necessarily follow that 
I should stop eating peanuts, just to be on the safe side, even though I have 
eaten them in the past with no ill effect? Or if some people die from bee 
stings that I should be deathly afraid of bees?
 Personally I believe immunity comes to those who are exposed to low level 
concentrations of giardia such as found in mountain creeks. I believe those who 
are first exposed to large concentrations, such as in swimming pools or day 
care center, can become ill in varying degree due to varying immune systems. 
>From this group comes the carriers who are likely to have numerous future 
outbreaks, and periods of dormancy during which the disease is communicable to the 
non immune. My understanding is that to become a carrier you must first become 
ill.
 Or it may be that those never exposed at all to giardia through early life 
are more prone to developing giardia from medium levels when exposed as adults
  There are much higher concentrations of giardia in the drinking water of 
San Francisco than found in Sierran lakes and creeks. Why are they not advised 
to treat all water and why is there no giardia epidemic there?
 So you can explain my lack of getting giardia after drinking untreated 
wilderness water for fifty years to just plain luck. I prefer to think that those 
medical people are right and that I am one of the immune ones. So why bother 
with an easily compromised filter. I just chlorinate the water on that rare 
occasion when cows or elk are sharing or have recently shared the same immediate 
water source. I also drink smart, such as taking water from the uphill side of 
the trail, because I have heard that horse doo doo rolls down hill. Well, duh!
   So are you immune to or a potential victim of giardia? Might as well ask 
me how you will react to a yellow jacket sting or to eating peanut butter. 
Beats the hell out of me 
  As for trying to imply that those who don't treat their water are spreading 
the disease, there can be only one enforceable solution: Force everybody to 
show a blood test showing they are giardia free before getting a wilderness 
permit. You know the old saying, you can lead an old hiker to water, but you 
can't make him treat it. Of course you could just make a regulation requiring 
backpackers to carry a filter anyway ala you know what
 And what do you propose to do with the bona fide giardia carriers who can 
spread the cysts no matter what they do with their water? Ban them entry? Set 
aside a "lepers" wilderness just for them?