SanFrancisco water has more Giardia than Sierra

“In fact giardia is not as bad as people think in any U.S. wilderness area. Read the report! Check the sources and the statistics!

Read the Report ”

“If you dig, you'll see that Hetch-Hetchy (One of San Francisco's Water Supply's) in not filtered at all. So that in it's self begs the question whether hikers really need to.

>>>By the way not that I know this I'll be sure to piss in it for John Muir's sake this summer<<<”

“Thanks for sharing this info. I have always felt that Sierra water was basically safe and stored my filter away years ago. Still, I use iodine when drinking from large lakes.

I liked what is said about blaming your friends. Those bastards!”

“I read something once that suggested most cases of backpacking giardia are self-infections, i.e. somebody didn't wash their hands good enough after taking a dump. Apparently many people have giardia in their bowel, but it only causes trouble in the stomach. Meuser included some statistics in his book which showed some large percentage of hikers never ever filtering their water, and mostly being okay.”

“It really is amazing that so many health care professionals and other 'experts' don't understand the lifecycles of parasites or their corresponding infectious dose. Parasitology really should be a required course in medical school. I'm glad I chose a graduate-level parasitology class as an undergrad elective.

How did the Giardia get in their bowels? Because they already have a low-level, sub-clinical infection (sub-clinical = not showing symptoms). After repeated self-reinfection due to bad personal hygiene (isn't the fecal-oral route of infection a pretty picture?) the parasite load level will reach a threshold sufficient to induce symptoms. How did the Giardia get there in the first place? They aren't native to humans, you can't be born with them and they didn't just magically appear one day. You have to be infected by an outside source. Another infected mammal such as another human, perhaps? (fecal-oral route of infection, remember? Getting prettier, isn't it?) Keep in mind that the natural parasitic host of Giardia Llamblia is the beaver. That fecal-oral route of transmission just keeps getting prettier, doesn't it?

Here's the lifecycle in a nutshell. The environment-resistent cyst is expelled with the feces where it disseminates (directly or indirectly) into the water (remember rain and soil erosion? remember that some animals defecate in or near the water). It can persist in soil and water for years in this state preserved, protected, and just waiting for a host. However it is transmitted, the cyst is ingested and is induced to hatch by the low pH (~2.0) environment in the stomach. As the now living organism travels down the intestinal tract and the surroundings become less acidic it is induced to attach to the upper intestinal wall (upper meaning the end of the intstinal tube near the stomach) and start feeding. It will remain there and produce and release new cysts to be expelled by the GI tract with the waste. This can continue indefinitely without any adverse effects if the number of these that are attached remain low. Once they reach a certain number (through chronic reinfection -or- a single massive dose) they will coat the upper intestinal wall. This prevents it from performing it's normal digestive function. The sugars that would normally be broken down there and absorbed pass through to the colon where they cause the symptoms normally associated with this infection.

It was a backpacking buddy of the Parasit. prof that got Giardiasis in the Sierras once (I've mentioned it before). Flagyl is used to treat Giardia sp. infection and is quite effective under normal conditions.

I never drink untreated water.

Have a nice day and try to keep that 'fecal-oral route' picture out of your mind, k?”

“skully, you have me convinced. I won't leave home without my filter. Besides, I already had a bout with untreated water. It wasn't pleasant.”

“Reminds me of a skit I saw on SNL once. It was a fake ad for a pair of glasses called "Fecalvision" Put 'em on, and the $#!T that's on stuff is highlighted bright green. The skit included a part from the perspective of someone wearing these glasses in a restaurant. Of course, there were dribs and drabs on every surface, but the food was glowing it was so bright green.

I thought I would die laughing.”

“I always filter my water anyway, but I also take extra care washing my hands after visiting my local backcountry cathole.”

“Yeah, those public cathole areas really are a health hazard.

My favorite angry retort: "Eat #&%!$ and live!" Haahahahahaha!”