[Hulksmash]

Yep you have it.

[wolffie]

I have read (but can't vouch for) articles questioning the waterborne Giardia hazard. http://www.farnorthendurance.com/busting-the-myths-about-giardia/ Google "giardia myth". Pertinent questions: "Were you diagnosed with giardiasis?" Lots of other stuff gets blamed on Giardia. Example: my pal was bedridden for a week after Peru (spent the flight home on the plane's toilet), and was cured immediately after he found one lonely leftover Septra DS antibiotic tablet in his pants pocket; Giardia should not be at all susceptible to Septra DS. "Was it waterborne?" It is suggested that fecal-oral, not waterborne, is the major route of transmission. WASH YOUR HANDS. I work in a hospital, and they're banging this into our heads all the time, as if we're kindergartners. It works! Hospital infections decline after these campaigns. I often decline to shake hands, esp. if I'm walking the dog (picking up dog sh!t) or backacking solo (I get careless about hygiene, since I already have all my own germs). I raise my palm and say, "Sorry, my hands aren't clean". Tip: keep a tiny soap vial in your buttwipe kit. When you return from your dump, your partner drops a drop into your hands, and dribbles water over them while you scrub. BTW, They teach us to scrub for about 30 sec (long time), with special attention to fingertips. Away from camp. Don't eat poop. Not even invisible amounts of it. This said, people do get Giardiasis. If you've been diagnosed with it, you know you've got it.

[DIYSteve]

The site linked by wolffie cites data compiled by Ronald Mueser, the father of our bud Ted My giardia was confirmed by culture tests both times. I also had amoebic dysentery in 1976 from a suspect "spring" in KY. All 3 were from lower elevation (montane or lower) water sources. I still don't bother treating or filtering water in seldom-visited high country. Yeah, I think lots of ailments are erroneously attributed to giardia. GI track distress can result from numerous bacteria, viruses and protozoa.

[Hulksmash]

I spent many decades not treating backcountry water without getting sick. I got sick once, if i stopped treating my water it would probably be many decades before getting sick again. Most water sources are safe.....the problem is there is no visual signs of the few unsafe ones. Filters are 3.0z thees days and filter a million gallons. Why not carry one. Here's something to think about. This year i've been spending lots of time at a particular trail doing maintenance. I've left multiple deposits. I even found a perfect deposit log with room for multiple deposits. A few months ago there was a salmonella recall on peanut butter. Guess what.....i had tainted peanut butter, and got sick in the back country. A few weeks later i returned to this trail....when i went to my poop log i discovered all of my previous deposits had been excavated. Everything consumed down to the wipes. What ever critter that ate my poop probably does not know or care about pooping away from drinking water sources.

[Backpacker Joe]

[tigermn]

CDC guide to what kills what...

[AlpineRose]

Many giardia carriers are asymptomatic. These carriers still excrete cysts, which can be passed on to infect others. It's the most common waterborne pathogen in the world, and can be found anywhere.

[Badger]

Hulk- Hope you are trailing again soon. This subject makes me wonder- historically, how did Native Americans treat this disease? Or did they have an immunity/tolerance built up against it? Or has this already been discussed?

[Randito]

[DIYSteve]

When considering the statistics, note that the majority of giardiasis is contracted in civilization -- e.g., domestic water supplies, hot tubs, swimming pools, wading pools, person-to-person contact, food -- and that only a small percentage of giardiasis is contracted from mountain water sources.

[JVesquire]

[Chief Joseph]

I am pretty sure I contracted it from unfiltered lake water used to make soup and tea a couple times...did not bring to a full boil. On the bright side I have quit drinking alcohol (not recommended with the anti-biotics) and I am losing weight due to loss of appetite.

[AlpineRose]

[ranger rock]

It's not generally a deadly illness and you do tend to develop immunity to it once you have had it. I got it at the ocean after drinking water treated with Iodine. Human milk kills it. I scientific paper about Giardia: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC88932/ Human Innate Immunity In some patients, giardiasis resolves within a few days, while in others the symptoms last for years, even in the presence of circulating antibodies in serum or secretory antibodies at mucosal sites and the cell-mediated immunity. Because of its biological characteristics, it is likely that nonimmune factors play a role in susceptibility to infection or in the duration and severity of the disease. For example, normal human milk kills G. duodenalis trophozoites independently of specific secretory IgA antibodies (68). A number of laboratories have demonstrated one giardiacidal factor present in milk, such as conjugated bile salts (70), unsaturated fatty acids (160), or free fatty acids (154). When grown in vitro in the presence of human milk, trophozoites can be protected from its giardiacidal effect by addition of intestinal mucus to the culture medium (203). G. duodenalis trophozoites are killed by products of lipolysis present in human duodenal and upper jejunal fluid (50). Aley et al. (11) have also reported that human neutrophil defensins and indolicidin have antitrophozoite activities when they are added to the culture medium. These results demonstrate the importance of nonimmune mechanisms in the control of the parasite population in the intestine. On the other hand, mechanisms of innate immunity may protect the parasite from destruction. For example, mucus has been reported to protect the trophozoites from being killed by lipolytic products present in the intestinal fluid (205)

[kiliki]

I thought I'd bump this up because I recently had it, and hopefully this post might be useful to others. My main symptom was becoming lactose intolerant. I thought it was odd that that my dairy intolerance seemed to come on suddenly, but as long as I didn't eat dairy my stomach seemed fine, so I just chalked it up to Becoming Middle Aged. I had also lost some weight and I am an already small person and because of that, my doctor told me to go see a GI doctor. They tested me for everything and it was giardia. I took the antibiotic and it seems like I can indeed eat cheese again. *whew* I know people have mentioned that you can have giardia and be asymptomatic or have mild symptoms, and my symptoms were quite mild except for when I'd eat pizza or put milk in my coffee. It's hard to say if I got it in the backcountry, since I answered yes to just about all of my doctor's questions. Yes, I've been out of the country, drank the water in French Polynesia, own a dog, volunteer with dogs at an animal shelter, drank (filtered) water in the backcountry (but I'm not fussy about some untreated water getting on my bottle), drank well water, been swimming in the ocean and in lakes, eaten in restaurants, attended potlucks and picnics (yes those are all trouble spots)...