I know a lot of people who use bleach to disinfect their water. Its much cheaper than chlorine and iodine tablets and just as effective.
I still stick with a water filter just because I like to filter any sediment out of my drinking water, but its always a personal preference.
Jeremy
Jeremy Day
I got Giardia at 11,000’ drinking straight out of a spring. Many time what looks like a spring was surface water higher up then goes underground a while.
It only takes one elk or deer to contaminate. I would never drink untreated water although I have heard of many people that do. In my opinion it’s not worth the risk. It took me 6 weeks to get rid of the diahrea. Your choice.
Woofer
Woofer,
I can’t tell you how many times I’ve heard stories like yours. However, in almost every case it amounts to a hiker getting diahrea and then attributing it to giardia in the water without actually having giardiasis medically confirmed or the suspect water scientifically tested. Unfortunately, diahrea can be caused by any number of bacteria or viruses which can be transmitted through any number of vectors and any number of behaviours can heighten the risk (weak hygiene practices being the most significant). Just so everybody’s clear, did you 1) have your giardiasis medically confirmed through tests, and 2) have a sample of the spring water tested? If you have not done both of those, it would be preferable to be more circumspect about diagnosing your diarhea and attributing it to particular vector (it probably was not the water).
That being said, caution is advisable in Colorado anywhere that livestock is present (which can occur at surprisingly high elevations). Giardia is not the primary concern in this case, but rather e coli or salmonella. In most cases, at 11,000 feet it should be possible to see the entire watershed that is being drained by the spring or stream, and you can make an appropriate judgement about whether the watershed is part of a grazing area. Personally, most of the water that I drink in the wilderness is untreated, but I am fastidious about my hygiene when preparing meals or eating (Purell alcohol gel is great stuff when hiking).
I would encourage all hikers to read the following article and take an appropriate risk-based strategy to avoid sickness…in most cases, that strategy should be more focused on hygiene:
http://www.latimes.com/travel/la-os-giardia26jul26,0,5873015,full.story
http://www.latimes.com/travel/la-os-giardia26jul26,0,5873015,full.story
Loup
Giardia IS a problem in Colorado.
From the Colorado Department of Health:
"Colorado and its streams and watersheds are tied closely with this disturbing pathogen. In these mountain environments, where the water appears crystal clear, it is sometimes difficult to treat water with rapid rate sand filtration (Lin, 1985). In fact the first outbreak suspected to be caused by giardia was in Aspen, Colorado during the 1965-66 winter season (LeChevallier, 1991). The Colorado Department of Health has also conducted several studies that show a widespread presence of giardia lamblia cysts in surface waters throughout the state. They obtained these results using standard methods of cyst recovery on different filters. Their study concluded that all Colorado surface waters are at risk (Lin, 1985). Because giardia lamblia cysts can remain viable for up to sixty days in cold water, Colorado’s frigid climate does nothing to stand in the way of this pathogen. "
grumpy
Sheep grazing at 12,000+ feet is not uncommon and believe me you don’t want to drink untreated water from a creek, stream or river downstream from a herd of 1,000+ sheep. SJ Ron
San Juan Ron
Loup?
You recommend sleeping with your food because you did, and drinking untreated water. When someone mentions they caught Giardia you demand proof.
IMO, you are not a very responsible trail user.
stultz
Responsible trail user? No, neither responsible nor irresponsible.
I take a variety of risks based on a subjective assessment of adverse outcomes. Sleeping with your food vs hanging it is one such decision; the question of when and where to treat water is another; the decision of when to hike during bad weather and when to shut it down for the day is another; the decision of whether to hike alone or carry a gun are another two. We all make hundreds of these types of decisions every day based on a subjective risk assessment. It’s not a question of being responsible or irresponsible.
My response to Woofer’s assertion that he caught giardia from a specific water source was to merely point out that he should characterize any linkage between his illness and the water as a suspicion, AT MOST, not a fact. As I am sure you know, the incubation period of giardia is usually between one and two weeks. So my point to Woofer (and anyone else who has ever asserted that a particular water source made them sick) is:
Unless Woofer has actually verified that A) the sickness was actually giardia; and B) the specific source had giardia present, it would be appropriate to be more circumspect about linking the water to a subsequent illness. You may have seem this notion in a different form, “post hoc, ergo propter hoc.”
Beyond the observation that circumspection would probably be appropriate, the only other point that I attempted to make was that we shouldn’t be excessively paranoid about water when there are any number of vectors that are probably higher risk than water.
Best regards.
Loup
I am employed as a statistician in a CDC testing center. I can tell you with certainty that we have positively identified numerous giardia lamblia infections associated with backpackers in the Rocky Mountains. In most cases, the parasite was contracted by people who thought they were drinking clean water and did not take precautions.
I can also state with certainty that giardia lamblia IS NOT found in uninfected individuals, as has been asserted in a previous post. Poor sanitation practices only result in infections if someone in the group is infected to begin with. Some people have no distress or symptoms from giardia so it is certainly possible to contact it from such an individual. This is a common means of infection in some parts of the world, primarily by workers in orphanages changing the diapers of infected children. (Not a very likely scenario on a hike.) Plenty of other things you can get from bad sanitation, but giardia is low on that list, at least for hikers.
The CDC firmly believes that surface water from any source should be boiled, filtered, or chemically treated. People who contract an infection should be tested and treated. Not treating an infection makes you a risk to others.
CDC Phd
CDC PhD,
Excellent post. Which tests has the CDC conducted that have found water sources in the Rockies with 10 or more viable giardia cysts in a volume of water that a hiker can reasonably drink (ie, maybe cysts/10 litres)? I take a risk based approach and I’d love to see the CDC’s published work that shows how many viable cysts are floating about in the water.
The second question I have is about person to person infection. You have acknowledged that people who have giardia are sometimes asymptomatic, hikers often hike in groups, and food preparation is often conjointly conducted, and snacks are readily shared among hikers. Yet you seem to be relatively nonplussed about personal hygiene, despite the primitive facilities. Does the CDC have a viewpoint that giardia is not a$$hole-to-mouth disease as all other credible organizations have concluded?
In your professional view as a statistician, does the CDC ever have a bias to err on the side of precaution? As a professional economist I can certainly tell you how we view the CDC’s recommendations…
Loup
As a professional nothing, (still in school for electrical engineering!) i’d still like to point out that CDC PhD is neither:
nonplussed about hygiene
“Plenty of other things you can get from bad sanitation”,
nor is it his believe that giardia cannot be transmitted by ingesting the fecal matter of an infected individual
(example provided of 3rd world diaper changers)
Correct me if I have drawn the wrong conclusion, but it is
his opinion that the probability of human to human transmission is low on a hike.
(probability of infected group member * probability of successful transmission)
Andrew M
Andrew,
You have drawn entirely the correct conclusion. The stated opinion was that person-to-person transmission was unlikely.
The second stated opinion was that purification of water was recommended, which would imply that water borne giardia is likely enough to justify a mitigative measure (according to the CDC’s view of the world).
Given the material that I have read about actual tests of water in the east and in the Sierras, the observation is that giardia is present EVERYWHERE, but not in sufficient concentration to reasonable conclude that a person could contract it. I have not seen any credible testing that suggests that there is sufficient concentration of viable giardia cysts in actual bodies of water tested to cause a human to contract giardia.
Again, if anyone has seen any literature that shows a prevalence of actual test that yield at least 10 viable giardia cysts (the minimum number required to cause giardiasis) in perhaps 10 litres of water (a plausible level of consumption), I’d love to see it.
If people like the CDC are recommending a “precautionary” stance, then come right out and declare that it’s precautionary and not scientific. I’m quite comfortable with the notion of a precautionary approach, but all the precautions that I take will be considered in the broad context of the risks that I face when I hike (ie, wildlife encounters, hypothermia, lightning, hitchhiking, human encounters, other injuries). The mitigative measures that I elect to take will be driven by the best credible information that I can amass and will be prioritized on a risk basis.
Best regards.
Loup
Hey - lay off of Loup. It’s nice to get the opinion of someone who arrogantly does everything wrong then argues passionately about it. As long as you do the opposite of what he says you will be ok.
jerens
Thanks for the link. I find it of particular interest that one of the CDC identified high risk groups is backpackers.
“persons taking part in outdoor activities (e.g., backpacking or camping) who consume unfiltered, untreated water or who fail to practice good hygienic behaviors (e.g., hand washing)”
grumpy
Giardia comes from poop, be it human or otherwise. So, the big question. Does the water have poop in it?
Considering that humans, cattle, sheep, elk, beavers, and deer are all pooping mammals that carry Giardia, maybe a better question would be, is there any water along the CT that doesn’t have poop in it?
We place our bets and we take our chances…
AJ
CDC PhD,
Thanks for the link, it was a good read. I also perused the bibliography and noticed that it includes a reference to an article that is particularly relevant to the subject, “Risk of giardiasis from consumption of wilderness water in North America: A systematic review of epidemiologic data.” I had not yet read that article, so your link was doubly useful
Is there any reason to question Welch’s meta-analysis?
As this whole thread seems to have taken on a somewhat religious character (either you have faith or you don’t, and those who do not have faith are castigated by those who do), this is my last post on the matter.
Loup
Looks like I’m going to have to infect myself with giardia and poop in all the CT water sources to definitively settle this matter
(Joking!)
Andrew M