Thanks for sharing, steelie-

when you compare giardia to other waterborne parasites-
guinea worms , for instance-the giardia seem pretty tolerable.

!!! Shades of Alien! Yikes!

I had giardia once, and there was nothing occasional about the symptoms. I took what the doctor called "Flagyll" on the script and that got rid of the giardia. Then I drank about a gallon of buttermilk and ate about half a gallon of yogurt to replace everything else the meds got rid of too.

The symptoms from Giardia infection for me ranged from mild discomfort to full on distress, and though variable, were constantly present. The meds left me with a raw feeling inside, ravenously hungry.

My sister got giardia from the ice in her margarita in Nogales, Mexico, so don't only "not drink the water" there, I guess. It apparently lived in the ice (her doctor stated).........
I live in Cali, so I'm fairly sure the snow, except it very high elevation, is not safe, based on the airborne particulates present everywhere.........
Cryptosporidium, and/or brain eating amoeba critters (I forget the scientific name, causes encephalitis or similar), I think I'll always treat my water, either by UV or long boil or chlorine or something.........

Interesting. I've always been advised not to get ice in my drinks in Mexico, but I didn't think that it would be giardia that would be the issue. I've read that giardia is killed by freezing temps. Can giardia really be contracted from ice?

I'd be curious to see some research on particulates on California. I suspect such research would reveal it's not much of an issue in California. California isn't prone to acid rain. I wouldn't collect snow near a road or railroad track, but otherwise I think you'd be pretty safe even at lower elevations

Both my wife and I have had it, and we both had severe symptoms. It's not pleasant, like having constant stomach flu. Like Benjammin, we took Flagil (Metronidozal, I think), and it works like magic in a day or two. But you have to take the whole 10 day course.

I did some searching. The answer? "Yes." Giardia can and does survive freezing. Ice (or ice cream for that matter) made with contaminated water is not safe.

However, giardia does not survive well in freeze-thaw cycles for more than two weeks. See also this article. Therefore, what I've read is true, that in areas that experience freezing winters, giardia contamination must be re-introduced every spring. It's no wonder then that places like the Sierra Nevada in California have very little giardia. See this article. Perhaps the most important protocol in the Sierra is not water treatment but hand sanitization.

Again, I'm not trying to dissuade people from treating their water; water treatment is always a good precaution. However, in a survival situation, particularly one in a wilderness area with cold winters, drink. Oh, and wash those hands.

Hikin Jim, you're a wealth of knowledge!

And I'm sure, in Nogie, that ice was fairly fresh....

And yes she went undiagnosed, and then misdiagnosed, for nearly 2 years, just suffering through bouts as the critter went through it's cycle. If I recall, it finally took a third stool sample before a doctor spotted it (humiliating for her).

And yep, dirty hands probably account for the vast majority of contamination.

For the particulate matter, you know as well (since you live in SoCal) as I that you can practically taste the air out here, it's gotta be something more than just CO2 making the sky thick. An ounce of prevention, but you could bet if I was in dire straits I'd take the chance.

Re my previous posts:

If heat is availible from a fire, which you are using to warm yourself, you might as well take advantage of the situation to sterilise your water.

Absolutely. Particularly in cold wx, boiling beats the pants off of chemical treatments. Chemical treatments take a long time in very cold water. Instead of the 30 minutes listed on the iodine bottle, several hours are required. With chemical treatments, you're almost better letting them work overnight. Chemicals? Nah. Burn, baby, burn.

There's a bit more of a problem in areas where fuel is scarce or fires are prohibited. I guess a filter is your best option in cold wx under those circumstances, but one has to be careful to not leave water in the filter. Water left in the filter may freeze, rupturing the filter and rendering it useless. Alternatively, one could bring in a white gas (or canister depending on the type and conditions) stove and boil one's water, but that can add a lot of weight and bulk to one's kit. If temps are well below 0C/32F, then one will probably want to bring a stove anyway. With those temp, the water available tends to be the solid kind.