Water born Diseases-To Filter or not to Filter...that is the question?

[Wise Old Owl]

I noticed that as a group we get a little hung up about drinking from streams… To filter or not to filter is that the question… then the questions get focused on Giardiasis (http://en.wikipedia.org/wiki/Giardiasis) – but clearly we forget about Campylobacteriosis (http://en.wikipedia.org/wiki/Campylobacteriosis), E. coli Infection (http://en.wikipedia.org/wiki/E._coli), Dysentery (http://en.wikipedia.org/wiki/Dysentery), Cyclosporiasis (http://en.wikipedia.org/wiki/Cyclosporiasis) and the two biggies Cholera (http://en.wikipedia.org/wiki/Cholera), Typhoid fever (http://en.wikipedia.org/wiki/Typhoid_fever). Well there’s something we haven’t discussed. After watching several survival shows they are all about boiling water. Those on the reality show, that don’t filter or boil, quickly fail in about 4-5 days and get rushed to the hospital. And the complete list of symptoms is even more disturbing, some of it is fatal. WIKI (http://en.wikipedia.org/wiki/Waterborne_diseases)

If in Mexico, Don’t order ice in your drink? Remember that old one? Would it shock you several restaurants in my Philadelphia area are still on a well and one of them locally tests positive from time to time with E Coli in the ice? The drain field is too close to the well. So why can some of us drink from the streams and others languish in their sleeping bags for a few days with flu like symptoms? Why did American Indians avoid Beaver fever? Well they didn’t – they from time to time got sick too. Before the time of early American settlers digging wells in Philadelphia and farmers excavating springs for spring houses, in the depths of Pennsylvania there was the American Indian, and I chose this as the Lenape Indian covered the most of the Government Trail later named the AT. Before the walking purchase they did suffer from fevers, but from repeated exposures while growing up gave them some immunity, and turned them into carriers. 7% of today’s Americans are carriers and the percentage is several times higher for outdoors people, children, and the world population in general.


· It's easily spread. Combine poor hygiene with the fact that a million Giardia organisms can hitch a ride under a single fingernail, and in no time your camp will be doing the Beaver Fever Quickstep.

· It's persistent. Cysts can live several months outside the body.



Studies have shown that a high percentage of Beaver, Muskrats, and Cattle are infected with Giardia, so it was assumed they were the primary source of the Giardia organism infecting humans. That is until the growing amount of data showing that Beaver living downstream from campgrounds have a high Giardia infection rate, compared with a near-zero rate for Beaver living in more remote areas. Here we were blaming the poor Beaver, and it now looked like we were infecting them!
Sure enough; a 1979 study concluded that “humans are considered the most important component" in the spread of Giardia. More recently, an article in the 1990 issue of the scientific journal Environmental Management states that “waterborne transmission of Giardia is believed to be the least common mode of transmission overall.”



When it comes to protecting your health from unsafe drinking water, you need to know as much as possible about the types of waterborne bacteria, viruses and cysts that exist and how to prevent them. When it comes to protecting your health from unsafe drinking water, you need to know as much as possible about the types of waterborne bacteria, viruses and cysts that exist and how to prevent them. Please read on for information about preventing water-born disease.

[Wise Old Owl]

SYMPTOMS – Traveler’s Diarrhea (Mostly E-Coli)

Most cases of Traveler’s Diarrhea begin abruptly. Typically, a traveler experiences four to five loose or watery bowel movements each day.
Other commonly associated symptoms are nausea, vomiting, diarrhea, abdominal cramping, bloating, fever, urgency, and malaise.
The good news is that Travelers’ Diarrhea is rarely life-threatening. The natural history is that 90% of cases resolve within 1 week, and 98% resolve within 1 month.

SYMPTOMS - Giardia and Cryptosporidium



Diarrhea, abdominal cramps, gas, malaise, and weight loss are the most common symptoms caused by Giardia. Vomiting, chills, headache, and fever may also occur.
These symptoms usually surface six to 16 days after the initial contact and can continue as long as one month.
The symptoms of cryptosporidiosis are similar; the most common include watery diarrhea, abdominal cramps, nausea, and headaches.
These symptoms occur within two to 25 days of infection and usually last one or two weeks; in some cases they persist for up to a month.



SYMPTOMS - Dysentery


People afflicted with amoebic dysentery often suffer profuse, bloody diarrhea along with a fever, intense stomach pain, and rapid weight loss.
Bacillary dysentery causes small, frequent stools mixed with blood and mucus. Cramps are common, and a patient may occasionally strain painfully, without success, to evacuate the bowels.
Symptoms may range from mild abdominal discomfort to full-blown dysentery characterised by cramps, diarrhea, fever, vomiting, blood, pus, or mucus in stools or tenesmus. Onset time is 12 to 50 hours


Are There Viruses In Our Recreational Lakes, Rivers, and Streams?

I have done some digging and you might be surprised at the answer. CLICK HERE (http://globalhydration.com/sites/default/files/documents/Blog/Are%20There%20Viruses%20in%20Our%20Lakes,%20Rivers %20and%20Streams%2009202012.pdf) to see the report. There is mounting evidence from reliable sources that:

“Waterborne viruses are much more prevalent than anyone –including the experts – ever realized. Viruses like noroviruses, hepatitis A, hepatitis E, rotaviruses, enteroviruses, adenoviruses, and astroviruses, as well as avian influenza (orH5N1, the so-called “bird flu”) are present in surface watersources such as rivers and lakes around the world including Canada and the US.
That may be because there is more raw sewage entering our waterways than perhaps the average person realizes. A report released in 1999, for example, revealed that five cities in Canada dumped a combined total of 365 million liters of untreated sewage every day.”

If you're visiting or living in an area with poor sanitation, be especially wary of the water. Prevention is easier than seeking medical treatment once infected.

Do not drink untreated water from a spring, stream, river, lake, pond or shallow well. Assume it is contaminated with animal, bird and/or human feces. Disinfect with sanitizer’s or boil for 1 to 5 minutes depending on elevation.

Not all filters are capable of removing many bacteria and viruses. Check manufacturer’s claims carefully and be wary of filters that are not capable of removing viruses. When in doubt, treat with Sanitizers after filtration. In many places, the food can be as risky as the water. You should be especially suspicious of salads, uncooked fruits and vegetables, unpasteurized milk, raw meat, shellfish, and any foods sold by street vendors. Avoid eating raw fruits and vegetables unless peeled in your presence.

[Wise Old Owl]

Finally, let me offer this gem.

A lot of initial work to debunk the overwrought specter of Giardia lambia was conducted in the Sierra Nevada Range. This article by Dr. Robert Rockwell (http://www.sierranaturenotes.com/naturenotes/Giardia.htm#_edn2), makes a slam-dunk point that gets lost in the Giardiasis hype by looking at Giardia cysts concentrations in the waters of the Sierra Range and the water supplies for major California cities. The slam dunk point is that Giardia lamblia cysts are omnipresent, including in the Los Angeles and San Francisco water supplies. The San Francisco concentration of cysts, ingested by millions of people every single day, was higher than any source in the Sierra Range. Rockwell goes on to quote from Welch, Thomas R. and Welch, Timothy P.: Giardiasis as a Threat to Backpackers in the United States: A Survey of State Health Departments. Wilderness and Environmental Medicine, Vol. 6, 1995:

“Neither health department surveillance nor the medical literature supports the widely held perception that giardiasis is a significant risk to backpackers in the United States. In some respects, this situation resembles (the threat to beachgoers of a) shark attack: an extraordinarily rare event to which the public and press have seemingly devoted inappropriate attention.”
Is the article flawed?

[Wise Old Owl]

From the Article another "Nugget of Truth"

On a recent climbing expedition to Tibet, members of our party came down again and again with what was undoubtedly giardiasis. Our water came from glacial melt, but all our food in advanced base camp and below was prepared by Sherpa cooks. Much of the food they prepared—potatoes, rice, cauliflower, cabbage, onions—came from Nepal. We were continually assured that the cooks were practicing good hygiene, yet we had major intestinal problems that prevented many of the participants from getting high on the mountain.

Practice good hygiene such as frequent hand washing and disinfection of cutlery, cutting boards, etc. Wash hands thoroughly and frequently using soap or after having been to the toilet.

A simple rule of thumb is "Disinfect >or boil it, cook it, peel it, or forget it.



The take away here is: If you do get sick blame your friends for not practicing good hygiene on the trail!

[squeezebox]

I plan on getting tested for Giardia and Lyme disease when i finish thru hiking just because. Some people get it without signs & symptoms.
Not a bad idea for any high mileage hiker to get tested once a year. Long term effects can be real nasty.
MHO

[Old Hiker]

Which is why I filter AND chem treat my water, regardless of "conventional wisdom".

I'm wondering: earlier start = less people on Trail = less contamination? Just a thought.

[Pedaling Fool]

You ask this in your OP: "So why can some of us drink from the streams and others languish in their sleeping bags for a few days with flu like symptoms?"

The same reason why some of us are better at running or gymnastics or hiking or mathmatics, and the list goes on....

And it's the same reason why some animals in nature die and others live, while others strive and still others thrive.

The only reason this is such an issue is the product of two reasons: 1) our naturally-given instinct to survive. 2) Our seemingly unnatural ability to reason.

The only real difference between us and other animals WRT finding ways to survive is our ability to reason and communicate ideas to others and attack challenges in a systematic manner via networks.


My post is focused at the root cause, because you threw a lot of stuff out there. There are way too many topics to address individually.

[Wise Old Owl]

I didn't get into long term effects - and I am not sure what happens when you are a carrier. - I am most likely a carrier as I drink from some high streams & springs without filtering.

I did not get into chemical contamination from tailings from mining or spills, even though that does exist on the trail as well - that will be a future idea to revisit.

[Pedaling Fool]

Your title: Water born Diseases-To Filter or not to Filter...that is the question?

Are you asking for yourself?

[Dogwood]

Studies have shown that a high percentage of Beaver, Muskrats, and Cattle are infected with Giardia, so it was assumed they were the primary source of the Giardia organism infecting humans. That is until the growing amount of data showing that Beaver living downstream from campgrounds have a high Giardia infection rate, compared with a near-zero rate for Beaver living in more remote areas. Here we were blaming the poor Beaver, and it now looked like we(humans!) were infecting them! Sure enough; a 1979 study concluded that “humans are considered the most important component" in the spread of Giardia. More recently, an article in the 1990 issue of the scientific journal Environmental Management states that “waterborne transmission of Giardia is believed to be the least common mode of transmission overall.”

If this is true it is yet just another example of the commonly prevalent human centric mindset and haughtiness(hubris).

[Pedaling Fool]

Studies have shown that a high percentage of Beaver, Muskrats, and Cattle are infected with Giardia, so it was assumed they were the primary source of the Giardia organism infecting humans. That is until the growing amount of data showing that Beaver living downstream from campgrounds have a high Giardia infection rate, compared with a near-zero rate for Beaver living in more remote areas. Here we were blaming the poor Beaver, and it now looked like we(humans!) were infecting them! Sure enough; a 1979 study concluded that “humans are considered the most important component" in the spread of Giardia. More recently, an article in the 1990 issue of the scientific journal Environmental Management states that “waterborne transmission of Giardia is believed to be the least common mode of transmission overall.”

If this is true it is yet just another example of the commonly prevalent human centric mindset and haughtiness(hubris).
How so? I'm not doubting it, but curious how we are infecting the beavers; my bet would be something along the lines of our large numbers and the waste we create...

[Dogwood]

One of the most significant factors in whether or not I decide to treat my water is how heavily impacted by human activity the area is. That's because I believe it is humans who sometimes(often?) carry and spread parasites/disease through their poor hygiene, industrial agricultural farming practices, etc. Yet, humans often have a self absorbed way of placing their activities up upon a pedestal ignoring the consequences of their behavior I these types of outcomes.

[Wise Old Owl]

Glad you picked up on that - it flies in the face of conventional wisdom - that's why I stuck it in there. People tend to think once exsposed and cleaned up by medicine that we no longer have a "bug" not true, we become carriers. I thought it was a good topic and I will look some more into it.

It is true for Lyme disease if caught early, I don't test positive anymore (got tested two months ago)

A lot of hikers & backpackers get exsposed & sick from Giardia and never go to the doctor, if the symptoms clear up after a week.

[lemon b]

Wow. As a general rule I filter these days and carry aqui mire. Back in 1978 when I hiked Dawsonville to Front Royal I boiled and carried bleach. Drop or two a quart.

At home I have my well 140 feet uphill from my leach field, than another 140 to the brook from the leach field. I change my in home filter every 4 months. Know lots of people who bypass the filter. Not sure if testing the brook just for the heck of it would be worth the cost and time since beavers live in the pond feeding the brook. What would make me really concerned would be if the brook trout ever leave.

Only time I ever got sick from water was from being really really thirsty and finding I had forgot my filter.

One time I heard the local preacher say that more future wars would be caused by a lack of water more than anything else. That maybe ringing true in Africa even today. Lets hope Vegas and Calif. get there water problems solved.

[rocketsocks]

This is already all pretty well documented, treatment an filtration is the way to go. All the razzle dazzle could be more truncated and succinct with out the wag the dog, I mean beavers tail.

So to answer the question to Filter or not to filter...Yep, I filter, an treat as well, might even decide to drop some UV on the little critters to render them sterile.

[swjohnsey]

I only treated water a couple of times. Much/most of the water along the trail comes right out of the side of the mountain, not much chance of Giardia or anything else. Beaver fever was around before there was much population. Most "Giardia" is undiagnosed so it could be anything and is most likely ecoli. A drop or two of household bleach per quart is not enough. I did some independent testing and found that it usually took at least 3 drops/pint to get residual chlorine. You won't find many beaver or cattle along the trail because they don't usually live on ridgelines.

[JohnnySnook]

Getting sick is no fun. I've suffered greatly during many surf trips to central and south america. Usually only to or three days of hell. I'd try and only drink bottled, water, sodas, and lots of beer. The problem is that you just never know what the people serving you are up to. That can go for your friends also. I'd rather double up on water purification than suffer thru any stomach issues if possible.



One time I heard the local preacher say that more future wars would be caused by a lack of water more than anything else. That maybe ringing true in Africa even today. Lets hope Vegas and Calif. get there water problems solved.

This may be a fact of life soon. I think once the water issues get worse we'll up the effort to desalinate the oceans.

The drought is only going to get worse for the west over near future. More people and less rain not a good thing.

Here's seven major rivers around the world that don't even reach the ocean anymore.
http://environment.nationalgeographic.com/environment/photos/rivers-run-dry/

Pivot TV often replays the TV series "The Future of Water" which were produced in 2011. They are quite interesting watch if you get a chance.

[Wise Old Owl]

To my knowledge it's 9 rivers, add the Rio Grande, there is a wide sandbar at the mouth that is in Google Earth.

OK Back on track - Tabs and drops
Chlorine-dioxide
Aqua Mira
Clorox drops
Ef Clor
MicroPur
Iodine tabs or drops ( I cant use this)

Did I miss one?

[rhjanes]

The Ice issue.....often it is the ice machine itself, growing mold, not being cleaned, or disinfected. My work until recently had those "open it up, scoop out ice" deals. I quit using them and would walk down to the cafeteria. Why? Watching people dig around with their hands in the ice! Looking for the scoop someone failed to put back correctly. Watching a guy walk out of the mens rooms after NOT having washed his hands, go down, grab the scoop and plunge in scoop and hand into the ice.....Same happens in restaurants. They still have the bins full of ice. Waitperson handles money, then "grabs" your drinks....with ice....using hand just wiped down a table, handled money, etc.....

[swjohnsey]

You need to build up your immunity. Germs are everywhere. You are full of them to included giardia and ecoli. From my observations, the folks who get sick most often are the most fastidious. Studies have shown that farm kids who grew up barefoot and eating dirt were healthier than kids from fastidious city households and that eating buggers builds the immune system.

[Wise Old Owl]

Yea I can see what you are saying about the ice - but I was specifically discussing a well known location, thank you for alternate explanation.

Sw Johnny Currently, Giardia lamblia is the most commonly diagnosed intestinal parasite in North America.22 It is the most frequently identified cause of diarrheal outbreaks associated with drinking water in this country. Fully 20 percent of the world’s population is infected, and up to 7 percent of Americans, most without any symptoms at all. The Centers for Disease Control and Prevention (CDC) estimates that as many as 2,500,000 cases occur annually in the US or almost one for every 100 persons. Infestation rates of 60 percent of the children in day care centers across the country have been noted.

In an incident in New Jersey a child had a “fecal accident” in a 700,000-liter swimming pool, and nine swimmers came down with the disease. How many Giardia cysts might have been involved? The number of cysts shed in feces is highly variable but has been estimated as high as 900 million per day for humans.

[norts]

I cant even see why there is a debate. You need to carry a filter for when the water is definitely questionable . You are carrying it so why not use it.
How much extra time does water filtering add to a walk compared to how many days you will lose if you get sick. Not to mention the discomfort.
I used my filter every day.
Taz

[Colter]

Finally, let me offer this gem.

A lot of initial work to debunk the overwrought specter of Giardia lambia was conducted in the Sierra Nevada Range. This article by Dr. Robert Rockwell (http://www.sierranaturenotes.com/naturenotes/Giardia.htm#_edn2), makes a slam-dunk point that gets lost in the Giardiasis hype by looking at Giardia cysts concentrations in the waters of the Sierra Range and the water supplies for major California cities. The slam dunk point is that Giardia lamblia cysts are omnipresent, including in the Los Angeles and San Francisco water supplies. The San Francisco concentration of cysts, ingested by millions of people every single day, was higher than any source in the Sierra Range. Rockwell goes on to quote from Welch, Thomas R. and Welch, Timothy P.: Giardiasis as a Threat to Backpackers in the United States: A Survey of State Health Departments. Wilderness and Environmental Medicine, Vol. 6, 1995:

“Neither health department surveillance nor the medical literature supports the widely held perception that giardiasis is a significant risk to backpackers in the United States. In some respects, this situation resembles (the threat to beachgoers of a) shark attack: an extraordinarily rare event to which the public and press have seemingly devoted inappropriate attention.”
Is the article flawed?

Both articles are deeply flawed. Among the CDC, FDA, EPA, Mayo Clinic and all the state health departments, I don't know a single one that accepts the conclusions of either article.

Rockwell's widely quoted claim that there are more giardia cysts in SF water than Sierra water? SF doesn't filter their water, but they treat it with Chlorine dioxide AND chloramine. So the cysts in their water supply? Over 99.99% dead. Poisoned twice over. In modern water treatment plants. I debunk Rockwell's paper here (http://bucktrack.com/Giardia_Hiking_Water.html).

Welch's paper is equally baloney. Nobody has access to more data than the CDC. The CDC says

Anyone may become infected with Giardia. However, those at greatest risk are...

Travelers to countries where giardiasis is common
People in child care settings
Those who are in close contact with someone who has the disease
People who swallow contaminated drinking water
Backpackers or campers who drink untreated water from lakes or rivers (my bold)
People who have contact with animals who have the disease
Men who have sex with men

I debunk the specifics of the main Welch paper here. (http://bucktrack.blogspot.com/2012/09/backpacker-giardia-debunking-skeptical_8.html) Additionally, the CDC has specifically refuted Welch (http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5709a4.htm) saying Although the advice to universally filter and disinfect backcountry drinking water to prevent disease has been debated, the health consequences of ignoring that standard water treatment advice have been documented

Despite this, water treatment is a personal choice, and many people report not getting sick despite not treating water. However, as a three time giardia veteran, and having researched the topic at length, I am going to follow the standard advice to treat all surface water.

[Kaptain Kangaroo]

I cant even see why there is a debate. You need to carry a filter for when the water is definitely questionable . You are carrying it so why not use it.
How much extra time does water filtering add to a walk compared to how many days you will lose if you get sick. Not to mention the discomfort.
I used my filter every day.
Taz

So true........sure, the risk might be low if you are careful, but the consequences are too nasty to chance it.....

Nothing worse than when digging a cathole is step 2 in the process !!!! :eek:

[Colter]

...SF doesn't filter their water, but they treat it with Chlorine dioxide AND chloramine...

I should have said UV light and chloramine.

[general]

Chlorine, especially sodium hypochlorite (bleach), and iodine are both compounds that can be very toxic to the human body. I do sometimes carry a filter in places where I know there will be cows or horses, not really for giardia or any of the crypto things, but more for Escherichia coli. Other than that, I never filter. There are other common coliform bacteria that can cause a positive result in a coliform test, that are not detrimental to human health. I would agree that digestive illnesses for hikers are more likely caused by poor hygiene. Someone scratches their butt crack and then sticks their hand in a bag of gorp, and sickness results with the quickness. There are always acceptable levels of all kinds of bad things in drinking water, from bacteria, to metals and nitrates. I would make the logical assumption that ground water available to you in the woods is much less likely to make you sick than the water that comes from your tap. Just the opinion of a currently licensed Class 4 drinking water operator of a transient community system.

[rafe]

Roland Mueser did some analysis back in the early 1990s based on questionnaires filled in by some 150 AT thru-hikers (finishers.) His conclusion (which was unfortunately not very conclusive) is that there was not much correlation between a hiker's getting sick on the trail with that hiker's preferred method of water treatment. Ie. all methods seemed to be equally effective or ineffective. For what it's worth, his book is still a great resource for the ins and outs of thru-hiking the AT, being based on those same questionnaires and his own thru-hike.

[RED-DOG]

I always filter my water if it's questionable or not, wash my hands, etc, don't let someone else touch your food, such as your Gorp bag, but what we can't forget about is Norovirus, a lot of folks gets water born illnesses and Norovirus mixed up, because the two is somewhat similar.

[Colter]

... I would make the logical assumption that ground water available to you in the woods is much less likely to make you sick than the water that comes from your tap. Just the opinion of a currently licensed Class 4 drinking water operator of a transient community system.

Please elaborate. Because testing for human pathogens in "wild" water vs. water that has run through treatment plants doesn't correlate with your statement. Neither does CDC data nor anecdotal evidence.

Perhaps I've misunderstood you?

[Colter]

I like the Roland Mueser book, but his poll was not scientific.

I'm going to quote a prior post I made on the topic:

There are several scientific papers that have clearly shown the importance of treating water, some specifically studied the A.T.:

"Health care needs of Appalachian Trail Hikers" ...Methods to purify water need to be used regularly (http://www.ncbi.nlm.nih.gov/pubmed/8482936)...

"Medical Risks of Wilderness Hiking" In a prospective surveillance study, 334 persons who hiked the Appalachian Trail for at least 7 days (mean [+/- SD] length of hike, 140 +/- 60 days) in 1997 were interviewed. ...Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water (http://www.ncbi.nlm.nih.gov/pubmed/12681456)...

"Influence of Hygiene on Gastrointestinal Illness among Wilderness Backpackers" Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water (http://www.ncbi.nlm.nih.gov/pubmed/14769284).

These are all peer reviewed scientific papers that studied what ACTUAL A.T. hikers did, and the results. The papers, according to my reading of the numbers, show that water treatment is MORE important than hygiene, but that BOTH are important. Note that the papers don't say "drink smart" they say to treat water ROUTINELY.

The only study that looked at hiker hand contamination (http://www.adirondoc.com/publications/hand_contamination_2012.pdf)of which I'm aware showed their hands were CLEANER leaving the field than when they started their backpacking trip. [A possible explanation being that in "civilization" our hands are exposed to the filth of many times more people.]

Additionally, NOLS has compiled perhaps the largest database concerning the prevention of hiker gastrointestinal ailments:

The National Outdoor Leadership School (NOLS), which emphasizes strict hand-washing techniques, water disinfection and washing of common cooking utensils in their programs, reports that gastrointestinal illnesses occurred at a rate of only 0.26 per 1000 program days. By contrast, studies of hiking trips on the Appalachian Trail that averaged almost 5 months, reported that more than half of the hikers experienced at least one episode of diarrhea (Wikipedia)

[Dogwood]

The advice to filter back country water is good general advice. But, it is just that good general advice for the general public.

I recently met three different(65 and 72 yr old males, one 67 yr old female) 30+ yr residents of northern Minnesota who either live yr round or work seasonally in the Boundary Waters Canoe Area(one's a fishing/hunting guide, one owns a lakeside resort, one lives on an island on a lake) who have RARELY to NEVER in ALL their MANY MANY YEARS OF NOT treating their backcountry water when in this area been medically diagnosed as having contracted water borne parasites despite having been MEDICALLY TESTED. Two said they HAVE NEVER treated their backcountry water elsewhere in California and Montana while in the outdoors. All three have been tested for intestinal parasites more than once, always when having diarrhea. I too have followed the same path in over 20 yrs actively back country hiking in the U.S.(mainly the Lower 48). I generally treat water less than 20% of my hiking days. Sometimes I treat less than 10% of the time I take water during the entire hike.

After having been medically tested, myself recently as two yrs ago, again after having sustained a bout of diarrhea, initially assuming it might be from impure water, as is often erroneously the situation, assuming like MANY others that diarrhea while hiking has to be caused from drinking tainted water, I was given a clean bill of intestinal health. Later, after much thought, teh Doctor and I traced the cause of my diarrhea to food poisoning while in town eating tainted seafood.

The advice here with the stats shouldn't be ignored but those people, as well as myself, and the others I know, who don't or OR SELECTIVELY TREAT, shouldn't be ignored either AS THE CDC, and some others, SEEM TO BE DOING IN FAVOR OF BLANKET RECOMMENDATIONS TO THE PUBLIC TO TREAT ALL WATER ALL THE TIME! OBVIOUSLY, not everyone is at equal risk! There are other factors involved that few want to discuss that allow some people, perhaps any person?, possibly using certain techniques or sound water capturing practices to lower or potentially completely avoid contracting water borne pathogens from some(all?) untreated U.S. backcountry water sources. I suspiciously believe one's general intestinal health, metabolism, and diet are some additional factors that assist in lowering contracting water borne parasites in the U.S. But, again, no one wants to discuss these situations. It's easier and probably more sound to give blanket advice.

[Dogwood]

BTW, the BWCA sustains sizable populations of moose and beaver both of which are often cited as carriers of Giardia.

[Colter]

So Dogwood, all four of you often/usually don't treat water, and all four have consulted physicians due to gastrointestinal problems? See the NOLS data, above. (by the way, people with symptomatic giardiasis often test negative (http://www.healthcommunities.com/digestive-disorders/giardiasis.shtml).)

We can, (and have in the past) cherry picked stories to illustrate people who do/don't get sick. Some examples of experienced outdoorsmen whose luck ran out... (http://forums.bowsite.com/TF/bgforums/thread-print.cfm?threadid=352483&forum=2)

Nobody, including myself or the CDC, is denying there are many people who don't treat water and haven't gotten sick. But it's like wearing a bicycle helmet, washing your hands, wearing safety goggles or any other safety recommendations: although these safety practices will ultimately prove "a waste of time" for many people, for many others it will save them considerable grief in the future.

There's no way of knowing what the future holds, regardless of someone's past experience.

[swjohnsey]

I suspect that most of the propaganda concerning contaminated water is generated by folks sell filters, chemicals and gadgets. The U.S. military is pretty good at living in the field. They still us iodine tablets to treat individual water. I used the stuff for about 15 years on a long range recon team. I drank disgusting water and never got sick. For big water they just back the water buffalo up to a stream. After it is full you pour in these glass ampules of what amounts to chlorine bleach. They probably has a PhD in the pentagon that is in charge of this stuff.

I drank untreated water except for a couple of spots, one was the James River and another was a shelter that the only water source was a beaver pond. Never got sick. I did get some entertainment watching all the folks furiously pumping and treating.

I read a report somewhere about a guy who tested many of the water sources along the AT. Very few had any giardia and most of those didn't have enough to matter.

[Coffee]

My view is why take a chance when the Sawyer mini weighs less than two ounces, screws onto my water bottle with no effort and costs $20? I don't doubt that most sources are just fine but why would I want to take even a small chance of having a major disruption to my hike when eliminating that chance is so cheap?

[rocketsocks]

My view is why take a chance when the Sawyer mini weighs less than two ounces, screws onto my water bottle with no effort and costs $20? I don't doubt that most sources are just fine but why would I want to take even a small chance of having a major disruption to my hike when eliminating that chance is so cheap?
Exactly............

[Lone Wolf]

I suspect that most of the propaganda concerning contaminated water is generated by folks sell filters, chemicals and gadgets. The U.S. military is pretty good at living in the field. They still us iodine tablets to treat individual water. I used the stuff for about 15 years on a long range recon team. I drank disgusting water and never got sick. For big water they just back the water buffalo up to a stream. After it is full you pour in these glass ampules of what amounts to chlorine bleach. They probably has a PhD in the pentagon that is in charge of this stuff.

I drank untreated water except for a couple of spots, one was the James River and another was a shelter that the only water source was a beaver pond. Never got sick. I did get some entertainment watching all the folks furiously pumping and treating.

I read a report somewhere about a guy who tested many of the water sources along the AT. Very few had any giardia and most of those didn't have enough to matter.yeah, lotta hype on treating/filtering. i've never done either and i've walked a mile or 2 on the AT the past 28 years or so

[rocketsocks]

yeah, lotta hype on treating/filtering. i've never done either and i've walked a mile or 2 on the AT the past 28 years or so
What freakin germ would want to live in your cast iron gut? they know nobody rides fer free. :D

[Colter]

I suspect that most of the propaganda concerning contaminated water is generated by folks sell filters, chemicals and gadgets. The U.S. military is pretty good at living in the field. They still us iodine tablets to treat individual water. I used the stuff for about 15 years on a long range recon team. I drank disgusting water and never got sick. For big water they just back the water buffalo up to a stream. After it is full you pour in these glass ampules of what amounts to chlorine bleach. They probably has a PhD in the pentagon that is in charge of this stuff.

I drank untreated water except for a couple of spots, one was the James River and another was a shelter that the only water source was a beaver pond. Never got sick. I did get some entertainment watching all the folks furiously pumping and treating.

I read a report somewhere about a guy who tested many of the water sources along the AT. Very few had any giardia and most of those didn't have enough to matter.

The propaganda theory can be applied to any safety device, in most cases with equal plausibility. Do you really think business interests have convinced all those public health agencies or bribed all the scientific paper authors and peer reviewers to say something that they know it isn't true? Is that why the Army had you treating water?

"I read a report somewhere about a guy who tested many of the water sources along the AT. Very few had any giardia and most of those didn't have enough to matter"

Another un-cited "I read it on the internet" quote. If such a study exists, please cite it. I'm very skeptical. One reason is that the infectious dose can be as little as a single cyst (http://ajph.aphapublications.org/doi/abs/10.2105/AJPH.81.6.709). Another is that, to quote the EPA, Giardia cysts are ubiquitous in surface waters of all qualities. (http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0CDsQFjAF&url=http%3A%2F%2Fwater.epa.gov%2Faction%2Fadvisori es%2Fdrinking%2Fupload%2F2009_02_03_criteria_human health_microbial_giardia.pdf&ei=6ikzVO2zEc2xogTyx4DoBA&usg=AFQjCNFohaykiJwV7kyMIO2RsRafYV3G1w&sig2=CHOaw2VhMP9rxhhmS5cu4Q)

[swjohnsey]

I think I'll call BS on that one. "Can be as little as a single cyst" is like saying you can win the lottery. I sure it may have happened. To say that giardia cysts are ubiquitous and that an infection can be caused by a single cyst defies logic when you consider the number of folks who swim in surface water.

In a fit of madness I decided to paddle a kayak down the Mississippi from Lake Itasca to the Gulf of Mexico. I drank nothing but Mississippi River water for the three months or so that it took filtered with an old T-shirt and treated with bleach. No problems.

[Colter]

I think I'll call BS on that one. "Can be as little as a single cyst" is like saying you can win the lottery. I sure it may have happened. To say that giardia cysts are ubiquitous and that an infection can be caused by a single cyst defies logic when you consider the number of folks who swim in surface water.


You again cite your opinion in response to scientific studies. If you had read the paper I cited, you'd see that swallowing a single cyst will result in an infection about 2% of the time according to the top experts in the field. Thus you could do a lot of swimming before your luck ran out. That said, many people HAVE gotten giardia swimming, kayaking, etc. after inadvertently swallowing water.


In a fit of madness I decided to paddle a kayak down the Mississippi from Lake Itasca to the Gulf of Mexico. I drank nothing but Mississippi River water for the three months or so that it took filtered with an old T-shirt and treated with bleach. No problems.

It would be more convincing had you not treated your water the whole way. What year did you do the Mississippi? Do you have an online journal? If so, please link to it.

People tend to expect other people's experience to be like their own. Sometimes it is, sometimes it isn't. I talked to a tugboat captain that grew up on the river. He said they drank the Mississippi untreated as kids. That made me shudder!

[Deacon]

BTW, the BWCA sustains sizable populations of moose and beaver both of which are often cited as carriers of Giardia.

Back in1985 my two boys and myself canoed for three weeks in the BWCA, and didn't even think about treating the water. We just went out about a hundred feet off shore and dipped out of the lake. We never had an issue.

[swjohnsey]

You again cite your opinion in response to scientific studies. If you had read the paper I cited, you'd see that swallowing a single cyst will result in an infection about 2% of the time according to the top experts in the field. Thus you could do a lot of swimming before your luck ran out. That said, many people HAVE gotten giardia swimming, kayaking, etc. after inadvertently swallowing water.



It would be more convincing had you not treated your water the whole way. What year did you do the Mississippi? Do you have an online journal? If so, please link to it.

People tend to expect other people's experience to be like their own. Sometimes it is, sometimes it isn't. I talked to a tugboat captain that grew up on the river. He said they drank the Mississippi untreated as kids. That made me shudder!

2009. No journal but I did do some posting about my trip over at paddling.net before they kicked me off.

[perdidochas]

I think I'll call BS on that one. "Can be as little as a single cyst" is like saying you can win the lottery. I sure it may have happened. To say that giardia cysts are ubiquitous and that an infection can be caused by a single cyst defies logic when you consider the number of folks who swim in surface water.

In a fit of madness I decided to paddle a kayak down the Mississippi from Lake Itasca to the Gulf of Mexico. I drank nothing but Mississippi River water for the three months or so that it took filtered with an old T-shirt and treated with bleach. No problems.

That's because you treated it with bleach. Some of us prefer filtered water to chlorine flavored water.

[Dogwood]

"So Dogwood, all four of you often/usually don't treat water, and all four have consulted physicians due to gastrointestinal problems?"

I've met many more than "four of us" in this situation! Many more. I only cite these few examples YES and NO. Speaking for myself Doctors were consulted and ordered tests based not only on gastrointestinal symptoms but for other symptoms as well - general malaise, fatigue, loss of appetite, vomiting, cold sweats, slight temperature, etc. And, these were not cherry picked examples, although I agree that is a typical scenario, just a few examples of the many people who have told me, and verified, the same thing. The one man and woman have been tested multiple times as well as I have, three times for me, so I find it very statistically unlikely that all these test results were false negatives as you're suggesting. :( You keep dismissing anything that disagrees with your current hardline perspective. And, on this thread, as well as previous threads, you do plenty of cherry picking of stats and coming to what I see as questionable conclusions based on a short list of assumptions and a few compiled statistical studies that could have other explanations or details not shared here. I was sincerely hoping you would be more open to discussing and exploring in rather deeper detail rather than simply continuing to unquestionably support your position.

"See the NOLS data, above. (by the way, people with symptomatic giardiasis often test negative (http://www.healthcommunities.com/digestive-disorders/giardiasis.shtml).)"

For me, this situation of "often" false negatives occurring brings up another question - why are false negatives occurring so frequently?

"We can, (and have in the past) cherry picked stories to illustrate people who do/don't get sick. Some examples of experienced outdoorsmen whose luck ran out... (http://forums.bowsite.com/TF/bgforums/thread-print.cfm?threadid=352483&forum=2)"

"There's no way of knowing what the future holds, regardless of someone's past experience."

Here's where you are again being adamantly disingenuous totally ignoring what myself, and others, have stated and verified. You continue to avoid discussing or acknowledging other possibilities that lower a person's risk contributing CONFIRMED MEDICALLY TESTED NEGATIVES, sometimes multiple tested negatives, to false negatives, or not contracting a water borne parasite in the U.S. backcountry drinking untreated water to mere dumb "luck or cherry picked hearsay to prove a pt, as if people have no or little control with what water one drinks. BS.

I don't buy it.

[Colter]

"Disingenuous?" Come on dogwood. :)

My position is a mainstream, science-based and data supported stance. I repeatedly link to papers to support my viewpoints. I have said multiple times that many people go for years and sometimes a lifetime without treating and without getting sick. Unlike many people I haven't said "don't treat and you WILL get sick" because I don't know that that's true. There are countless exceptions.

I guess I'm confused why you pointed out the four people, including yourself, who seldom/never treat water and have had undiagnosed ailments. I think the problem of false negatives for giardiasis tests is valid to bring up. There are often false negatives because cysts are released sporadically.

There is a long list of pathogens that are carried in water and can make people sick, salmonella, campylobacter jejuni, escherichia coli (E. coli), hepatitis A, yersinia entercolitica, Leptospira interrogans, cryptosporidium and giardia rotavirus, enterovirus, norovirus, so a person can test negative for one waterborne illness but be sick with another. I certainly can't say the sicknesses of your quartet are related to untreated water, I have no way of knowing, but you certainly can't know they aren't.

Another way my position is main stream is there can be little doubt that hand-washing and cooking/eating utensil care play a significant role in backcountry gastrointestinal health. I also know there have been verified outbreaks of giardia from untreated backcountry water, and to the best of my knowledge there has never been a verified backcountry outbreak that was hand-to-mouth.

"There's no way of knowing what the future holds, regardless of someone's past experience." Sorry, but it's true. And it works both ways.

There is absolutely no doubt a person can dramatically up their odds of not getting sick by carefully choosing water sources. There is also no doubt that luck plays a significant role because there are unknowable factors regardless of skill level. That's why the top experts do water tests rather than just looking at the water and pronouncing it pathogen free. I can cite many scientific studies showing pathogens present in pristine waters and in springs. As the EPA says, they've found giardia cysts in even the most pristine of surface waters. The kind of water that "experts" would chose.

Are you familiar with Backpackinglight and Ryan Jordan? Ryan Jordan, a Montana State University senior research engineer in the Center for Biofilm Engineering, is an avid backpacker who has tested many backcountry water sources (http://bwca.cc/tripplanning/waterfiltration.htm). He has found pathogens in clear water in places that would seem least suspect, and tested some nasty-looking sources that turned out to be pathogen-free.

I'm not arguing against people's right to treat or not treat as they see fit, I am primarily arguing against patently false (http://bucktrack.com/Giardia_Hiking_Water.html) misrepresentations of the available data and the conclusions of top epidemiologists. (http://bucktrack.blogspot.com/2012/09/backpacker-giardia-debunking-skeptical_8.html)

[jjozgrunt]

I never filtered when I was younger and in the military. I've drank some water from disgusting places and never had more than an attack of the farts. Others with me have drank the same water and have experienced everything from farts to raging vomiting and diarrhea. Some protection, IMHO, does come from our own bodies ability to resist virus and germs, "the cast iron stomach people". You only need to look at the flu season to see extremes of this. I also look to the fact that as kids, my generation were not as pampered with filtered and highly cleaned everything. It gave our bodies the opportunity to build up very robust immune systems.

I think some of the resistance to contamination of water is also a location thing. I couldn't imagine drinking the water from rivers in Madagascar while I was there, you just had to look for 5 minutes and see all the things floating in the water to make that decision, and in fact I was loath to wash in them either. But the locals happily drank straight from them, washed their bodies and clothes in the water and were very healthy.

Now I use either a sawyer filter or aqua mira depending on where I am, sometimes a combination. That with some half decent hygiene and washing your cooking/eating gear properly should be enough even for the AT water, which will be full of american germs. LOL I very afraid of one day waking up and saying y'all and god damm in every sentence or even worse wanting to wear Hawaiian shirts with plaid shorts or trousers.

[Dogwood]

Statistics cited, no matter how prestigious the credentials of those accumulating the stats, hold little wt for me until I fully understand the parameters of the studies and precisely how the stats were accumulated. For me, as a statistical mathematician I've learned any study can be biased, even unknowingly so, by the ones conducting the study or accumulating the stats. You cited two studies in another thread, one which I partly read through, that I immediately had serious questions concerning based on how the stats were accumulated and hence questioned the conclusions attained IN THE SAME WAY YOU DID in the Rockwell commentary and in the other article you cherry picked apart. I could do the same with the info you cite to support your viewpoints.

I understand where you're coming from though as someone who is seeking to understand you're own three separate bouts with Giardia and someone who, if I'm recalling correctly, also worked for the CDC. You're offering CDC policy as far as backcountry water quite similar to blanket general advice NP Rangers offer at Backcountry Reservation Offices. It's good general advice for the general public. I'm not debating that. I'm having offense that you still refuse to more deeply examine why some people don't get easily sick from water borne parasites - the "exceptions." I find it laughable that you continue to dismiss that this is possible writing these cases off to dumb luck or, after being tested and coming back negative, as false negatives. I suppose you do that because it doesn't fit nicely into your model of always treating backcountry water. After having this discussion with many outdoorsmen and backpackers in the U.S. who only selectively treat water and them not having been diagnosed with a water borne pathogen this "dumb luck" and false negative hypothesis you promote to explain these cases simply DOES NOT fit what I'm seeing.

[Colter]

Dogwood,

As a statistician you know that the plural of anecdote (mine or yours) isn't data.

There was no need to cherry pick errors in the Rockwell (http://bucktrack.com/Giardia_Hiking_Water.html) and Welch (http://bucktrack.blogspot.com/2012/09/backpacker-giardia-debunking-skeptical_8.html) papers.

I never used the term dumb luck. I think not treating and not getting sick is the result of some combo of immunity, general health, good water picking, and, yes, luck.

I never worked for the CDC.

False negatives are common in giardiasis tests. So are true negative tests. Many people have been untested and have never had giardiasis. Or have.

I'm sorry you disagree with me but you are free to do so.

I support your right, and the right of others, to not treat water if they so choose.

[Traveler]

A statistician with projectile drizzles is just as sick as a non statistician with Giardia....

Not many are desirous risking the statistical inevitability of contracting Giardia, toxoplasma, and crptosporidium by repeatedly drinking unfiltered water from various sources. While one person may claim to have survived unfiltered water sources for years, another who follows this path may find themselves having serious illness within two water sources, suffering needlessly and perhaps requiring emergency hospitalization.

Given the choices of water filtration/treatment technologies available today, in my view it makes little sense to take this risk, though I understand the ideal of being in the wilderness unfettered by technology. I would presume if one wants to be unfettered by technology in this circumstance they would not wear shoes/boots, not have a pack, not have a compass, or any of the many technological equipment we tend to carry with us. If you use these things, then it would stand to reason simple precautions against injury or illness to enjoy the experience make sense.

[coheterojo]

Hike your own hike. Do whatever you want with your water. I don't filter or treat. I've done 3 AT thruhikes. I've traveled from Mexico to Bolivia mostly on foot. It doesn't appear to me that the billions of people on earth that drink their water without using a filter or chemical treatment are all languishing in hospitals. Me neither.

[Colter]

Hike your own hike. Do whatever you want with your water. I don't filter or treat. I've done 3 AT thruhikes. I've traveled from Mexico to Bolivia mostly on foot. It doesn't appear to me that the billions of people on earth that drink their water without using a filter or chemical treatment are all languishing in hospitals. Me neither.

All likely true.

Also likely true: the World Health Organization says that every year more than 3.4 million people die as a result of water related diseases (http://www.voanews.com/content/a-13-2005-03-17-voa34-67381152/274768.html)...At any given time, close to half the population of the developing world is suffering from waterborne diseases associated with inadequate provision of water and sanitation services

[Kaptain Kangaroo]

All likely true.

Also likely true: the World Health Organization says that every year more than 3.4 million people die as a result of water related diseases (http://www.voanews.com/content/a-13-2005-03-17-voa34-67381152/274768.html)...At any given time, close to half the population of the developing world is suffering from waterborne diseases associated with inadequate provision of water and sanitation services

Yes, I imagine that people living in a developing country who struggle to access safe water supplies would be totally confused by someone from a rich country who had the power to make their water safe all the time and chose not to..............

[Traveler]

Yes, I imagine that people living in a developing country who struggle to access safe water supplies would be totally confused by someone from a rich country who had the power to make their water safe all the time and chose not to..............

All those "job killing regulations" yanno....

[coheterojo]

Jeez. I know. How cavalier of me.

[swjohnsey]

Did the CDC say Ebola was hard to catch?

[Speakeasy TN]

Great thread gentlemen! It's nice to see CIVIL disagreement.

On my first attempt I was told by a veteran of the Trail to take whatever treatment I wanted. He said I would be conscientious at first and would taper off when I got to a spring extra thirsty and sure enough!

This Spring the plan is to use Aqua Mira. What will the Sawyer Mini do for me if added to the packload?

FWIW I do understand that the odds that gastrointestinal issues end my hike are MINIMAL.

[Colter]

...FWIW I do understand that the odds that gastrointestinal issues end my hike are MINIMAL.

In a prospective surveillance study, 334 persons who hiked the Appalachian Trail for at least 7 days (mean [+/- SD] length of hike, 140 +/- 60 days) in 1997 were interviewed. At the end of their hike, subjects completed a questionnaire on injuries, illnesses, water purification methods, and hygiene practices...CONCLUSION: Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water. The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware. Medical risks of wilderness hiking (http://www.ncbi.nlm.nih.gov/pubmed/12681456)

[Speakeasy TN]

The most important reasons for ending a hike prematurely were injury, time limitation, and psychosocial reasons. The most common medical complaints were feet blisters (64%; n = 180), diarrhea (56%, n = 156),

The 56% number surprised me a bit until I thought about the effect of pre-packaged trail food on my system. Diarrhea does not equal bad water.

And no surprises in he conclusion.......wash your hands and your dishes.

CONCLUSION:Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water. The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware.

[Speakeasy TN]

So if I've decided on Aqua Mira, does the Sawyer Mini add any value if I double up?

[Sarcasm the elf]

In a prospective surveillance study, 334 persons who hiked the Appalachian Trail for at least 7 days (mean [+/- SD] length of hike, 140 +/- 60 days) in 1997 were interviewed. At the end of their hike, subjects completed a questionnaire on injuries, illnesses, water purification methods, and hygiene practices...CONCLUSION: Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water. The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware. Medical risks of wilderness hiking (http://www.ncbi.nlm.nih.gov/pubmed/12681456)

I'm a but skeptical of the conclusions of any self reported study like this and anecdotally I can say that poor hygiene and lack of handwashing seem far more likely disease vectors than drinking from a clean looking stream.

I'm not arguing against the importance of water treatment. I do treat my water and I recommend others do as well, but with all of the filthy things hikers touch each day, it seems that contact contamination would be much more likely to get you sick. So my opinion is: treat your water, but always wash your hands before touching food or your mouth.

[Cedar1974]

I learned from a very bad experience that you need to filter your water, always when out there. I was at a state park, and filled a jug with water from a faucet out there, thinking it was safe. The water didn't effect me, but a few months later, after washing it out thoroughly, I was driving along and drinking soda out of the same jug, then had to pull over at a hospital with extreme diarrhea. I can only assume the water contaminated the jug. From then on I filter and boil my water. I am even thinking of getting a Sanipen too.

[lonehiker]

I learned from a very bad experience that you need to filter your water, always when out there. I was at a state park, and filled a jug with water from a faucet out there, thinking it was safe. The water didn't effect me, but a few months later, after washing it out thoroughly, I was driving along and drinking soda out of the same jug, then had to pull over at a hospital with extreme diarrhea. I can only assume the water contaminated the jug. From then on I filter and boil my water. I am even thinking of getting a Sanipen too.

If you washed it thoroughly, why do you think it was the water from the faucet? I don't follow your logic. I think that it is much more likely that you got diarrhea from something you had recently eaten.

[Cedar1974]

If you washed it thoroughly, why do you think it was the water from the faucet? I don't follow your logic.

Well, because it was the next time I actually used the jug after I used it camping was on my road trip to Pittsburgh. So I think there may have been something left over in the jug.

[Speakeasy TN]

Almost lost a friend who opened a bottle of water on the way home and then drank out of it the next morning on the way to work. He had seeded the water with bacteria from his mouth (backwash). It sat in the hot car all afternoon but was nice and cool the next morning. Bacteria culture of his own bugs........

Sounds like maybe Cedar did something similar.