Re: [pct-l] Giardia on the trail

At 09:59 AM 12/1/00 , Staggerin' Willie wrote:
>are immune or partially immune to the bacteria.

Giardia is not a bacteria. It is a trophazoite that propagates my means of 
a cyst. Both forms are much larger than bacteria. They are easier to 
filter, but harder to kill with chemicals than bacteria.

>  I'm wondering if anyone out there has also heard this rumor, and more 
> importantly, if anyone has ever heard it conclusively proven or debunked.

The most common source of infection for non-traveling Americans is kids in 
day care.

 From what I have read, there is much variation in reaction to Giardia 
infection. Whether you consider having "no-symptoms" to mean you are immune 
is a matter of technicalities. You probably just have a sub-clinical 
infection that may give you problems if your immune system becomes 
impaired. Then again, the bugs may just not bother you because of your 
specific body chemistry.

No "conclusive proof" is available on Giardia resistance because that would 
require a double-blind study infecting a large number of humans with the 
bug and then testing them. Probably unethical.

There have been some CDC studies run on populations after exposure due to 
contaminated municipal water supplies.

If I recall correctly, about 10% of the exposed folks thought they were 
going to die, about 40% had moderate symptoms, about 40% had slight 
symptoms recovering without treatment, and about 10% had no symptoms.

Even if you don't have symptoms, you may still have the bug in your gut so 
make sure you always burry your excrement.

If you are patient, have a look at
http://www.uiah.fi/~btennoe/welltemp/other_sites/Panel_09_Water.html

Personally, I quite filtering water on my thru-hike and haven't filtered since.

-Brick

* From the PCT-L |  Need help? http://www.backcountry.net/faq.html  *

==============================================================================
To:            staggerinwillie@hotmail.com, pct-L@backcountry.net