"But I will happily treat all backcountry water for the rest of my life to avoid the next case."

Yes, I certainly feel the same way. I have had it, and it has gone away. Not really dibilitating, but, I didn't want to be far from a bathroom from three days. This was long ago...well over 50 years...

The point is that a large segment of the population is asymptomatic or only mildly effected. Do you know where you stand? Once you have had it, what are the chances of reinfection? What of the rural population that drink from untreated wells every day? Spring boxes can be real bad, yet, these people never get sick. Aquired immunity?

Yes, side waters are safest. This is where I sometimes drink. But, there was no paths and few animals in the area. Cold, clear, spring fed, running water, no different that what I have been drinking, probably a whole lot better.

That said, do I recommend treating water? Treatment is always recommended. Most hikers live in urban environments. Water is typically piped into their homes from some common source and it is treated. Chances are, they are highly suseptable to gardia. For an old farm boy, I can get away with drinking large amounts of gardia in my water. I am not immune, but, there is a level of tollerance. How much, I don't know. What is the mechanism? Why does it not seem to bother me as much as others? No answers, sorry. Just these and more questions....

What is the area like between Walker Pass and the Sierra? Alpine wilderness? Meadows used for cattle grazing?

Matt (iceaxe) I appreciate your detailed description of symptoms, helpful.

One thing is, that if your UV rarely breaks, drinking unfiltered water could be an acceptable backup. Rejecting UV because it's electronic and thus susceptible to failure may be over-reacting.

For anyone with a history of getting Giardiasis, I can see being more careful.

Hi, Buck,

'"Nineteen of these [Giardia] outbreaks were attributed to consumption of contaminated drinking water; only two outbreaks were reported among individuals identified
as campers or backpackers." http://download.journals.elsevierhealth.com/pdfs/journals/1080-6032/PIIS1080603295710468.pdf '
This is from the abstract of Welch 1995, which is one of the papers I referenced in the article. You've taken a sentence out of the middle of the abstract, and I think this lack of the proper context makes it easy to misinterpret what it says. The conclusion stated at the end of the abstract is that the data "...do not...provide any evidence that wilderness water is an important cause of the disease in this country." The paper actually concludes on pp. 164-165 that the two outbreaks were probably *not* due to drinking backcountry water.

Ben

Hi Ben,

Thanks for your response. The two reported waterborne outbreaks among backpackers were "one each in Alaska and Washington." According to my reading, the cases he debunked were from Utah and Colorado. And it's clear that those cases weren't conclusively debunked, either.

I respectfully think you are making a big mistake in logic in your reliance on this phrase: The surveillance data of health departments indicate that giardiasis is a common communicable disease in the United States. They do not, however, provide any evidence that wilderness water is an important cause of the disease in this country.

I think it's likely equally accurate to say this "They do not, however, provide any evidence that poor wilderness hygiene is an important cause of the disease in this country."

As I related before, my last physician (Mammoth Lakes) said he commonly treats backpackers with Giardia. He doesn't report it to the health department. And he said something to the effect that as far as he knows none of his colleagues do either. I don't think health departments get very excited about individual hikers getting sick, so they don't track it. We've already agreed, I think, that lots of hikers get sick from Giardia. The health departments "do not, however, provide any evidence that wilderness giardia is an important cause of the disease in this country."(my words.) Doesn't mean it isn't to the many who get it.

Edited by Colter on 02/25/2011 10:13:43 MST.

"The surveillance data of health departments indicate that giardiasis is a common communicable disease in the United States. They do not, however, provide any evidence that wilderness water is an important cause of the disease in this country."

Since I haven't read the paper I'm going out on a limb here, but my interpretation of that quote is that only a small percentage of the giardiasis cases across the US can be attributed to wilderness water. Consider:

1. Most Americans eat food prepared by other people, have children in daycare, touch doorknobs, shake hands, or engage in similar high-risk frontcountry behavior.

2. Relatively few Americans enter the backcountry at all, and a smaller subset of those drink untreated water.

The proposition that giardia in backcountry water can be a significant risk to backpackers who drink untreated water, is not at all inconsistent with the quoted statement that it isn't an important cause of the disease nationwide.

We still get it high up in the Rockies in Canada where few humans actually tread. Unfortunately Marmots, bighorn sheep, and smaller critters exist at higher altitudes and Giardia presents itself as a significant risk. I have had two hiking buddies get sick with Giardia and they were using Pristine (AM in Canada).

For me - that's a fact.

Howdy Buck and Ben,

What buck said: "As I related before, my last physician (Mammoth Lakes) said he commonly treats backpackers with Giardia. He doesn't report it to the health department. And he said something to the effect that as far as he knows none of his colleagues do either."

Exactly what the doctor told me at Stateline Medical center in South Lake Tahoe.
He had treated many cases Giardiasis and said it was not an unusual event at the clinic.
One of my thru hiker friends in 2009 also tested positive for Giardiasis at Mammoth Lakes and was told the same thing by the doctor there. He had to wait 5 days for the test results!
Giardiasis is not life threatening. It really sucks and it's uncomfortable and in extreme cases like mine i could have collapsed.
But most cases are not as severe.
I don't think the CDC would have accurate information due to doctors not reporting all incidence.
The only real way to find out the truth about the safety of water in the back country is to test it again.
Every one of those studies quoted are over 10 years old.
I respect the effort in writing the article but I question age of the science and the small nature of the sample sizes.
I don't see how a valid conclusion can be made regarding the safety of backcountry water today based on the inconclusive evidence of yesterday.

The doctor I saw in South Lake Tahoe originally prescribed Nitazoxanide but the none of the pharmacies anywhere around the lake had it so i was re-prescribed Metronidazole which is the generic for Flagyl.
As an aside, I now carry a course of Metronidazole (Flagyl). Less than an ounce for 7 days worth of antibiotic. The caveat being not everyone tolerates metronidazole and nobody should take a course of antibiotic without reason. You can have a serious reaction to metro particularly if you happen to mix it with alcohol.
One of the interesting things about this antibiotic is that despite it's dangerous nature; liver toxiciy and side effects, it is readily availiable without perscription labelled as "Fish-Zole" at online veterinary supply sites.
I don't recommend anyone else use an antibiotic labelled for animal use even though I and apparently a lot of other Long Distance hikers have.
Better to get a perscription from a doctor before your trip. Good Luck getting a doctor to write a perscription before the fact though.

Edited by Ice-axe on 02/25/2011 11:08:56 MST.

Repeating myself [a habit] backcountry water management is health risk management. For those who do not believe (and belief is part of this, as there's virtually no way to ascertain water quality, real-time in the field) their water supplies are contaminated by disease-causing microorganisms in meaningful concentrations--don't filter, don't treat, don't worry.

For those who suspect contamination, we have MANY treatment alternatives from simple to high tech. With research and field observation one can hopefully match the treatment to the situation, as these many alternatives do not address all forms of contamination equally well. Of course, technique and hygiene are necessary components of the scheme.

Has waterborne contamination been overhyped? Perhaps, but it's a big planet, water treatment technology has a worldwide market and water contamination is endemic in significant parts of it. Closer to home, can somebody backpack parts of the Sierra Nevada and not encounter waterborne contamination on their trip? Yes. (But, which parts at what time of year?) Can somebody thruhike the California PCT, or even the JMT, and not encounter waterborne contamination? No.

See the difference?

These discussions often get hung up on Giardia, which frankly becomes a distraction from the larger issue of water quality. When, say, drawing water from a lazy stream running though a cowflop meadow in September--because it's the only available water for miles--do you really care whether Giardia itself is present when bacteria and viruses are, with certainty?

Luckily the decision remains a personal one (not mandatory like bear canisters) but I consider it unethical to advise anybody that water treatment is unnecessary because there is no contamination.

Prost,

Rick

Echoing Rick's post somewhat...

Given the wide array of treatment from nothing to the elaborate, given how we are all different as individuals, and finally how we are dealing with [b]the unseen[/b] out there -- all this is a bit like religion. It's good to lay out the options -- but fruitless (if not nonsensical) to argue whether treatment is necessary or which method is best for everyone...

Benjamin, part of the problem is that too many backpackers do not know how to think about water quality. Unfortunately, we do not carry subminiature water quality labs around with us (although that would be a neat product).

I think about the elevation of the water first. In California, for example, there tends to be snow up high that melts through the spring and summer. If you can get very close to that newly melted snow water, it is almost foolproof. Yes, I have seen muddy little paw prints in the snow. If I can drink the meltwater as it first drips off the snow field, I generally don't treat it. As soon as the water has been running along the ground for a way, I generally treat it with something. Maybe it is a quick trip through a gravity filter. Once the water has been sitting around in a lake, I tend to get a bit more thorough. Maybe gravity filter plus some bleach drops. On extremely rare occasions, I have used iodine and have boiled the water also.

I don't believe that I currently operate in any areas downstream from grazing animal herds.

--B.G.--

Something is making a lot of people very sick. Convincing people to change their minds one way or another might be like shooting for a religious conversion, but this is real world stuff. Some things are provable, some unprovable. It's important that people make their own rational decisions and they need to hear both sides.

Of PCT thru-hikers last year, J. L. and M. L. also got Giardia. they were religious about filtering water after getting sick from giardia in the High Sierras C. D. got Giardia somewhere in that general area, I'm not sure where. P. was hit by Giardia, in the Sierras, and it took her off the trail. L. got Giardia south of Mojave. B. M. came down with it in Oregon. R. said he had it, I don't know where. R2. also. Don't know if either of the latter were tested or where they got it. And of course, me. That's just those I know about. (names abbreviated in the interest of privacy.)

It was J. L. that told me about Tinidazole to treat Giardia. It is new on the U.S. market, and has proven to work the best for most people.

"...backcountry water management is health risk management."

Right, risk is frequently defined as 'probability of occurrence x severity of consequences.'

So you can choose the level of risk to tolerate, eg, if you are on a frequently traveled trail that isn't more than a day from definitive medical care, or if your trip is only a few days, and you (and your group) are not that bothered by bailing on the trip when someone gets ill, then maybe you're comfortable with less rigorous water treatment.

OTOH, if you are going somewhere really remote for long periods, are in a foreign country without good medical care, are not carrying a satphone or extra food, water treatment chemicals, underpants etc. then maybe more water treatment is in order because the consequences of getting ill would be worse.

Getting at 'probability of occurrence' is harder...

"Good Luck getting a doctor to write a perscription before the fact though."

I have never had any difficulty getting my docs, there have been several, to write me an Rx for Cipro or Bactrim when I explained their intended use(hopefully none) and my protocols for deciding when to employ them. It's a matter of trust. Ditto for Hydrocodone, especially Hydrocodone.

Yes, before I travel to some third-world country on a high climbing expedition, I always request of my physician three items: Bactrim or some broad-spectrum antibiotic, Diamox for altitude, and some prescription-strength pain killer. Typically, he makes me describe how or why I would use each of those. Then, when it all makes sense to him, I get the prescriptions. I suspect that I could request Flagyl also.

Lots of big hospitals and HMO centers have a travel clinic. Often, they are even more experienced with strange drugs for strange places. They do injections, malaria drugs, and everything else, but you have to show them that you know where you are going and how long you will be there.

--B.G.--

"Unfortunately Marmots, bighorn sheep, and smaller critters exist at higher altitudes and Giardia presents itself as a significant risk."

+1 I drink water untreated about half the time in the southern Sierra, almost exclusively off trail, but I check VERY thoroughly for scat in the general area before making the decision whether or not to treat. Still, it is a calculated risk, modulated by instincts born of long experience in the area. Everyone has their decision making process, which is as it should be given that the consequences are very personal. I hypothesize that an additional benefit is that this reinforces the connection between actions and consequences in general, a connection ever more rarely made by the population at large, IMO. Maybe if everyone was responsible for their own water quality, insurance would be cheaper and we'd have a lot fewer people in jail? Sorry if I digress, but the connection was just too obvious, at least to me. ;-)

Heh heh... reminds me of an earlier hike up Mt. Baldy. We came across a clear stream and as my buddy bent down to take a drink, I pointed him toward a small herd of goats not more than 30 ft. away -- upstream -- drinking and possibly doing their business too.

http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html

Posting this link again for information.

Rick wrote:
"These discussions often get hung up on Giardia, which frankly becomes a distraction from the larger issue of water quality. When, say, drawing water from a lazy stream running though a cowflop meadow in September--because it's the only available water for miles--do you really care whether Giardia itself is present when bacteria and viruses are, with certainty?"

This is a very good point. But here's the thing. I really might care whether or not it's worth making efforts to kill off protozoan cysts, as opposed to bacteria and viruses. Quick, simple, low-weight, low-cost, reliable, and convenient methods can protect me against bacteria and viruses. The methods to protect myself against protozoans all have significant disadvantages. Steripens are expensive, filters are heavy and unreliable, and ClO2 tablets take many hours to work on cysts.

To me, the big issue here is that too many people are spending too much effort focusing on one issue (protozoan infections from drinking backcountry water) and not enough effort focusing on the issue where the payoff is orders of magnitude higher: potty hygiene.

Edited by bcrowell on 02/25/2011 19:24:06 MST.

Between Walker Pass and Kennedy Meadows on the PCT it's mostly cattle country. It's cattle country south of Walker Pass and cattle country north of Kennedy Meadows as well.

The thing about that article that bugged me is it's a typical article that tries to tell you everything you knew about X is all a myth, but there's all this other stuff you didn't think to worry about but should (blue green algae? the water at the surface of a lake?). So in the end you're left with the prescription to treat your water, just like before. So what was the purpose of that article except to make the person who wrote it appear smart?

Here is an article on Ben's side.

http://erikschlimmer.com/pdf/GiardiaMyth-Buster.pdf