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I probably have Giardia.. and it's no fun :-(
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Kevin Burton
(burtonator) - F

Locale: norcal
I probably have Giardia.. and it's no fun :-( on 04/17/2014 21:40:29 MDT Print View

On my last trip I'm pretty sure I caught Giardia.

I'm working with the doc now to get samples for testing to figure out what I have.

I remember exactly how it happened too! I usually treat water before I prepare food. So even if I boil it , it's still treated before hand. Double protection.

However, I've been skipping the boiling process and just waiting until the water was close to boiling. For Giardia, you have to wait for the water to boil for five minutes... Well, I forgot to treat it! I realized after I ate the meal. Ug.

I think the main issue is that it was the beginning of the season so I wasn't used to my normal routine.

Symptoms hit about 1.5 weeks after I got back to civilization. I was planning another trip and would have been in the woods by now :-(

It's miserable to do anything. Don't want to walk around. Don't want to do any exercise. Don't want to eat. Don't want to go to the gym.

... so be careful out there!

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 21:53:58 MDT Print View

"For Giardia, you have to wait for the water to boil for five minutes"

That is a common myth.

The kill temperature for Giardia lamblia is about 175*F.

The real problem is that too many people are lax about handling raw water and getting raw water on hands, etc.

They say that the best lessons are learned the hard way.

--B.G.--

Brian Mix
(Aggro) - MLife

Locale: Western slope, Sierra Nevada
Re: Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 22:06:51 MDT Print View

If I boil for treatment which is rare, I heat until bubbles form on the bottom of the pot and call it good. Never had a problem. I'm ----><----- this close to stopping treating my water when I *feel* it would be safe to not.

Kevin Burton
(burtonator) - F

Locale: norcal
altitude. on 04/17/2014 22:19:34 MDT Print View

To be fair, I was at a lower altitude, and the water was brownish... like tea color.

This was at about 4000 feet. So higher probability of Giardia.

Still not fun!

Philip Tschersich
(Philip.AK) - F

Locale: Kodiak Alaska
Altitude on 04/17/2014 22:45:57 MDT Print View

What does the altitude have to do with it, if I may ask? Something to do with the boiling point of water?

I have consumed hundreds (thousands?) of gallons of untreated water from throughout Southwest Alaska over the course of 25 years with no issues. I'm hoping I'm just a carrier (20-25% of infected people are asymptomatic). :^)

I believe you that's it's not fun. All the folks describing the symptoms don't have much good to relate.

Edited by Philip.AK on 04/17/2014 22:47:11 MDT.

Roger Dodger
(RogerDodger) - F

Locale: Wess Siide
Brownish water, tea color on 04/17/2014 23:00:49 MDT Print View

I wonder how well the katadyn hiker pro pump filter will do to clear up the brown tea color. I know katadyn does not remove giardia, just thinking about color filtration.

I also double treat for paranoia. Ceramic filter then those clorine bleach tablets.

Once my so called reliable water source was not a flowing stream in june, instead it was 2 inch deep of brown mosquito swarm. I opted for dehydration instead. Luckily I ran into an undocumented water trickle off a boulder with green algae. No bugs. I took that and 2x treated it. Still looked green hue like Mountain Dew or Midori Sour. I had brief stomach cramps but no issues. Cramps could have been from the algae water or the chlorine tablets.

Hope you recover soon. Please update us on your lab results and your doctor's advice.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Altitude on 04/17/2014 23:01:20 MDT Print View

"What does the altitude have to do with it, if I may ask? Something to do with the boiling point of water?"

Of course. The boiling point of water is around 212*F at sea level, then it lowers as the elevation gets higher. The boiling point of water is around 175*F at 19,500 feet, or about. If the kill temperature of Giardia is 175*F, then bringing it to a full boil will kill it anywhere up to around 19,500 feet.

In California, anywhere below 4000 feet is a good place to find lots of cattle or similar stock. Drinking the water down there is risky, so you probably want to be very thorough with water treatment.

The percentage of people who are asymptomatic will vary in most estimates. I've seen as high as 50%. Or it may be that some people just don't recognize some marginal symptoms.

I think that I would just rather avoid it altogether.

--B.G.--

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 23:03:31 MDT Print View

>"The kill temperature for Giardia lamblia is about 175*F."

+1 on Bob's data on pasteurization of water.

If you read an NPS publication, someone has seemingly surveyed everything ever written and taken THE most conservative approach, sometimes added more time and then published that. So they are people saying idiotic things like boil for 5 minutes, boil for 10 minutes, vigorously boil for 15 minutes, etc.

When I've talked to people who actually do plate counts before and after, who study pasteurization of water in the Third World, and who look at WHICH organisms survive, then you get answers of 90C for any time, 80C for a bit, 70C for XX minutes. So, yes, those bubbles that form before anything boils? You're done. If you can let it sit for an afternoon, 140F does it. Which exacts matches health department food-serving regs ("keep hot food hot and keep cold food cold") - long periods at 140F are protective.

There are extremophile organisms that can survive higher temps, but NOT pathological organisms. We're talking about your gut, not a mid-oceanic-ridge volcanic vent in a Nat'l Geo magazine.

>"and the water was brownish"

What was your "treat water before I prepare food" method? If chlorine or iodine, those have their limitations - cold water, too short a time, resistant organisms, and, maybe in this case, organic compounds in the water that react with the halogen. You should be able to smell that characteristic chlorine/iodine smell AFTER the contact period of 10-30 minutes (depending on water temperature). If not, maybe you didn't add enough, or maybe what you added reacted with sediments, tannins, etc, in the water. Your odor threshold is conveniently about 1 ppm halogens in water - the same level above which you are treating the water.

Also consider other pathways - wash your hands, but didn't sanitize them? I know someone who got Giardia not from "drinking" water, but from crossing a stream and getting some in his mouth. Hopefully, you wiped all the marmot poo off your titanium spoon before stirring your grits, so a fecal-oral route doesn't seem obvious, unless a pack animal or another human was around.

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 23:04:10 MDT Print View

They tell people to boil for 5 minutes because you need a rolling boil to purify but many don't truly understand what a rolling boil is.

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Altitude on 04/17/2014 23:07:59 MDT Print View

Curious as to why you suspect giardia instead of crypto? Treatment doesn't work well on crypto, like it does with giardia, so maybe it wasn't your suspect meal at all, but treated water you drank using only AM drops instead of a filter? Just speculating...

As far as altitude, I thought it had more to do with more downstream contamination, than altitude boiling temps...

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Brownish water, tea color on 04/17/2014 23:08:01 MDT Print View

"I wonder how well the katadyn hiker pro pump filter will do to clear up the brown tea color. I know katadyn does not remove giardia, just thinking about color filtration."

The Katadyn filter does 0.3 microns, so that should take out all of the Giardia cysts.

Chlorine bleach may or may not be effective depending on the pH of the water. Chlorine dioxide should be more effective, since it uses a different kill method.

--B.G.--

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 23:11:39 MDT Print View

"Hopefully, you wiped all the marmot poo off your titanium spoon before stirring your grits"

Now you've gone and done it. That alarming mental image will haunt me all summer.

--B.G.--

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Re: I probably have Giardia.. and it's no fun :-( on 04/17/2014 23:25:21 MDT Print View

>"They tell people to boil for 5 minutes because you need a rolling boil to purify but many don't truly understand what a rolling boil is."

Er, no.

Just no.

You don't.

Boiling is well over the temperature needed to pasteurize drinking water.

If you can't gauge temperature, boiling is a convenient, obvious end point. But bringing the water close to boiling is more than enough.

I don't care what the pamphlet the ranger gave you says. But if you've know of a peer-review journal article with data about infectious organisms living through X degrees but dying at X+5 degrees that differs from the above, I'd love to hear about it.

Marko Botsaris
(millonas) - F - MLife

Locale: Santa Cruz Mountains, CA
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 00:41:29 MDT Print View

You might want to actually wait until get your tests back before jumping to conclusions. There are a lot of things that can cause those symptoms.

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: Re: Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 01:56:10 MDT Print View

I have heard many times that you need a rolling boil to purify water, which I know is not true, but that is the common belief. The reason they tell you to boil water for 5 minutes is because, as many people believe, bubbles are not sufficient to purify water and you need a vigorous rolling boil. The 5 minute suggestion is meant so a newbie hiker will reliably get to a roiling boil, if they didn't understand what a rolling boil is. Obviously based on this thread you don't need a rolling boil.

Edited by justin_baker on 04/18/2014 01:58:07 MDT.

Glenn S
(Glenn64) - M

Locale: Snowhere, MN
Re: Re: Re: Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 03:18:49 MDT Print View

I can't figure out where this mythical "5 minute rolling boil" comes from. Even the CDC says only 1 minute, and even over 6,500 feet they only go to 3 minutes for recommendations. Both obviously extreme, but hey, it's the CDC, they have to be over-cautious, it's their job.

5 minutes though?! There wouldn't be any water left to drink after it all boiled away. Maybe I should take some classes, or attend some meetings, so I can learn all this mis-information being handed out.

Michael Gunderloy
(ffmike) - MLife
Re: Re: Re: Re: Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 04:55:11 MDT Print View

Maybe it comes from vendors of gas cylinders ;)

As for the OP, my sympathies. Whatever the reason, the symptoms are no fun. There are times I wish some of our fine young men in Scouting had more people who've been through a round to talk to. Then maybe they wouldn't do boneheaded stuff like crap next to the stream they're camping by and later wade out into the middle in bare feet and take a drink of the raw water. But boys are invincible at that age...

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
I probably have Giardia.. and it's no fun :-( on 04/18/2014 05:14:59 MDT Print View

Dave T. is correct. You don't need to boil it. I usually figure anything in the US of A can be treated with a boil. This will not remove other things, though. Chemicals, minerals, toxins can still be present. This will usually result in an almost immediate illness...usually within 24 hours or less.

You CANNOT get sick from yourself. Anything you have is already in you. Anything you do not have is not present in fecal matter, soiled clothing, or anything else you touch or ingest. It cannot happen. Illness is always an external event. (Well, 'cept cancer...)

I suspect that you simply did not wait long enough for the chemical treatment to work. It will take 15min to up to 6 hours depending on the temp.

I have had it, it is absolutly no fun. Good luck at the doctors. Even the cure is no fun. But, that said, I have only had it once in 40+ years of outdoor camping. I am quite sure I simply did not wait long enough.

Chemical treatments and filters are statistical. Even a .03 filter is never guaranteed to keep you safe. It may remove 99.99999% of the bugs, but not 100%. Even if you did things correct, you can still be infected. Most people just assume they are safe, not true. It only takes one... Cells never divide evenly. A cell that is 5 microns may produce two daughter cells: One at 4.99micron, most of the contents, one that only contains a little celluular material and half the nucleous at .01 micron. This is why they are never rated as absolutely, 100%'ly, guaranteed to work...only to four or five "9's".

I never treat and boil. This is a waste of treatment. If I am going to boil water for breakfast, there is no reason to treat it.

spelt with a t
(spelt) - F

Locale: SW/C PA
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 07:09:11 MDT Print View

>> What does the altitude have to do with it, if I may ask?

In the lower 48 at least, the higher you go, the less chance there is something pooped upstream.

Owen McMurrey
(OwenM) - F - M

Locale: SE US
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 08:02:07 MDT Print View

I've had giardiasis from drinking directly from a stream when I was in the Boy Scouts ~30yrs ago. The water looked and tasted fine(ha); 'course it turned out that it flowed right through a bunch of cow pastures shortly before. A lot of our wilderness areas in the South are surrounded by, and often drain from, agricultural land. The only safe assumption here is that it's all contaminated.

Pasteurization of water doesn't actually need 175F, it's more like 150, but it has to stay there for several minutes, while higher temps kill giardia faster. From the perspective of someone heating water on a stove or fire, you might as well bring it to a boil, unless you happen to carry a thermometer to verify the actual temp it's reached. I suppose you could stick it in there while it simmers for 6 or 7 minutes at 150F or so just to "prove" that's good enough.
Having had giardiasis, playing it safe really doesn't seem like that much trouble to me, though.

Marko Botsaris
(millonas) - F - MLife

Locale: Santa Cruz Mountains, CA
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 08:28:00 MDT Print View

" Cells never divide evenly. A cell that is 5 microns may produce two daughter cells: One at 4.99micron, most of the contents, one that only contains a little celluular material and half the nucleous at .01 micron. "

And this is not even to mention that the "holes" in the filter are statistically distributed as well. Probably those have an even greater dispersion of sizes. Rated 1 micron, for example, only means % of particles 1u in size that get through is X, where X is some small number believed to be safe enough.

It has been a while since I had an orgy of reading the literature, more than a decade, so I'm rusty. My understanding is that the dormant giardia cysts can survive a lot of mistreatment and are much harder to kill. I know/ they can stick around in the gut for a while, but I don't remember if they can wake up on that time scale and in those conditions, or if the "danger" is just that they will get crapped out somewhere where they will spread the distribution.

HK Newman
(hknewman) - MLife

Locale: Western US
Hang in there on 04/18/2014 08:32:36 MDT Print View

Sometimes our hiking is grounded from events resulting from our actions or beyond our control (grounded due to a kwappy dental suturing job myself). It's happened, ... nothing can be done except recovery, working on other stuff. A good excuse to get some household stuff done or do some reading.

Edited by hknewman on 04/18/2014 08:34:26 MDT.

Andy F
(AndyF) - M

Locale: Midwest/Midatlantic
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 08:33:50 MDT Print View

Unfortunately, there's just no way to know where you caught your illness, whatever the specific pathogen might be. It could have been contaminated food from a restaurant a few days ago.

I've consumed plenty of carefully-selected untreated and unfiltered water from wilderness streams without getting sick, yet my worst cases of intestinal illness were likely from salad bars and restaurants with freshly-made sandwiches.

Marko Botsaris
(millonas) - F - MLife

Locale: Santa Cruz Mountains, CA
Re: Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 08:43:18 MDT Print View

"There are extremophile organisms that can survive higher temps, but NOT pathological organisms. We're talking about your gut, not a mid-oceanic-ridge volcanic vent in a Nat'l Geo magazine."

And here's a shout out for thermus aquaticus, one such bacterium that was found in steam vents in Yellowstone - without whose heat resistant DNA polymerase the human genome project, modern genetic testing, and the whole current wave of the molecular biology revolution would not have been possible. There should be a gold-plated steam bath somewhere cared for in perpetuity so their ancestors can live out their lives in luxury and splendor. :-)

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 08:44:59 MDT Print View

Finish a course of flagyl and be done.
No big deal (at least for me).

Just don't make the same mistake again.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 10:02:38 MDT Print View

"And this is not even to mention that the "holes" in the filter are statistically distributed as well. Probably those have an even greater dispersion of sizes. Rated 1 micron, for example, only means % of particles 1u in size that get through is X, where X is some small number believed to be safe enough."

It depends on the filter.



From the Sawyer web page -

"Each Sawyer filter is certified for ABSOLUTE microns; that means there is no pore size larger than 0.1 or 0.02 micron in size. This makes it impossible for harmful bacteria, protozoa, or cysts like E. coli, Giardia, Vibrio cholerae and Salmonella typhi (which cause Cholera and Typhoid) to pass through the Sawyer PointONE™ biological filter. At 7 log (99.99999%) the filter attains the highest level of filtration available today.

"If viruses are an issue, we offer the Point ZeroTWO Purifier (0.02 micron absolute pores). This is the first and thus far only portable purification device to physically remove viruses. And it does it at a >5.5 log (99.9997%) rate, exceeding EPA and NSF recommendations."

Elliott Wolin
(ewolin) - MLife

Locale: Hampton Roads, Virginia
RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 11:29:05 MDT Print View

"You CANNOT get sick from yourself. Anything you have is already in you. Anything you do not have is not present in fecal matter, soiled clothing, or anything else you touch or ingest. It cannot happen. Illness is always an external event. (Well, 'cept cancer...)"

I've heard the opposite, i.e. that the flora and fauna in your lower digestive tract are kept separate from your upper digestive tract (e.g. stomach) by a valve system that makes sure the former don't get into the latter. When it does you can get sick.

Thus it is very important to wash your hands before food preparation, even if you are just cooking for yourself.

Can someone verify this?

HK Newman
(hknewman) - MLife

Locale: Western US
Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 11:59:13 MDT Print View

... Thus it is very important to wash your hands before food preparation, even if you are just cooking for yourself.

Can someone verify this? ...


Bacteria are ubiquitous (all sorts of species and strains all over us, on us, or in us), so it just makes good sense to wash hands. Fecal matter is not sterile but once out, all sorts of additional microbes can start growing on it very quickly (exponential growth - where one cell becomes two of the same cells is called binary fission). Also remember we are talking about a microscopic scale. The human immune system plays a role too, I guess.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 12:11:47 MDT Print View

>"flora and fauna in your lower digestive tract are kept separate from your upper digestive tract (e.g. stomach) by a valve system that makes sure the former don't get into the latter. When it does you can get sick.

Thus it is very important to wash your hands before food preparation, even if you are just cooking for yourself.

Can someone verify this?"

Yes. Your own e. coli are fine in your lower GI tract. You'd be "irregular" without them. But ingest a fair number of them and you'll be quite sick for a while.

A long-term, large-scale field experiment has been done: Rafting trips - living out of a boat on the Colorado River for 16 days with no plumbing or outhouses - used to have a fair number of sick rafters. In concert with requiring rafters to pack our all their poo (yes, the rangers check), private and guided trips went to a system of hand washing. Between the "groover" (the ammo-can you poop into) and camp, there is a wash station. You can't leave the groover without passing it. Also, there is great social pressure to use it (because others don't want to get sick) after pooping, before preparing food AND before eating (so you'd often wash hands three times in an evening. There is a 5-gallon bucket of bleached river water with a foot pump to a faucet. The faucet is over a waste-water bucket (so gray water can get dumped later). And there is alcohol-based hand sanitizer to use after soap and water. The groover and the wash station are the FIRST thing set up and the LAST thing packed up, so as to maximize usage. Since trips went to this system, sick rafters have been much rarer. But it is a combination of regulations, fines, education, hardware, procedures, peer pressure, and awareness of the consequences (helicopter rescue of a dehydrated rafter, for instance).

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Solar thermal and solar non-thermal treatment. on 04/18/2014 12:30:57 MDT Print View

>"Pasteurization of water doesn't actually need 175F, it's more like 150, but it has to stay there for several minutes"

That's what I've heard from specialists in third-world water treatment. Or 140F for an hour or two. A college friend devised a little capsule of high-temp oil with a string and a washer than would invert at 140F. So if the solar tank got hot enough during the day to invert the little gadget, it was good to go. If not, you'd give it another sunny day. 17 cents of parts and no batteries required. He was playing with a tube-in-tube heat exchanger in another design, because once to temperature, the solar-heated water could be used to pre-heat more water. He was only getting 18% efficiency on the HX because, I theorized, of laminar flow (thermosiphons are slow). "Dale, what's a granular material readily available for free in the third world?" After he packed the HX with coarse sand the efficiency went to 55%.

There's another approach that's probably more broadly useful and cheaper. A PEET bottle, with no label, left in full sun for a day renders it safe to drink. A "table" of corrugated roofing, sloped towards the sun makes a convenient holder of such bottles. Just keep track of which ones have seen a day of sun. For a base-camp setting or a zero day on the river, it could save a lot of fuel and/or pumping effort.

Cut&past from wikipedia:

Exposure to sunlight has been shown to deactivate diarrhea-causing organisms in polluted drinking water. Three effects of solar radiation are believed to contribute to the inactivation of pathogenic organisms:

UV-A interferes directly with the metabolism and destroys cell structures of bacteria.
UV-A (wavelength 320–400 nm) reacts with oxygen dissolved in the water and produces highly reactive forms of oxygen (oxygen free radicals and hydrogen peroxides) that are believed to also damage pathogens.
Cumulative solar energy (including the infrared radiation component) heats the water. If the water temperatures rises above 50 °C (122 °F), the disinfection process is three times faster.
At a water temperature of about 30 °C (86 °F), a threshold solar irradiance of at least 500 W/m2 (all spectral light) is required for about 5 hours for SODIS to be efficient. This dose contains energy of 555 Wh/m2 in the range of UV-A and violet light, 350–450 nm, corresponding to about 6 hours of mid-latitude (European) midday summer sunshine.

At water temperatures higher than 45 °C (113 °F), synergistic effects of UV radiation and temperature further enhance the disinfection efficiency.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: I probably have Giardia.. and it's no fun :-( on 04/18/2014 12:44:42 MDT Print View

Pretty soon we will hear if Kevin is a regular guy again.

--B.G.--

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 13:04:08 MDT Print View

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=63223&startat=80

Read through these articles and comments. DK is a microbiologist. I studied a year and a half as part of nurse training. (Hey, most nurses are FEMALE.)

Generally, you do not reinfect yourself with anything from your own body. Maybe a few parasites. The e. coli in your body is not the same strain as the one that makes you sick.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 13:27:15 MDT Print View

"Generally, you do not reinfect yourself with anything from your own body."

The women who have dealt with UTI/cystitis from improper wiping might disagree.

Or is that just another urban myth?

Edited by greg23 on 04/18/2014 14:30:37 MDT.

Roger Dodger
(RogerDodger) - F

Locale: Wess Siide
Re: Re: Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 13:45:31 MDT Print View

Well we are going off topic from Giardia to e.coli, but I disagree with the above statement that you cannot infect yourself with anything from your own body.

e.coli in the same person's intestine is not present in the bile, liver, blood, other fun organs.

It is a very serious issue when a person has an e.coli infection, even if the culprit strand is found in the output. starts with fever symptoms, spike high temp, stomach pains, dizziness.

At the hospitals in the US, a person with an e.coli infection is treated with hazardous material Infectious Disease gear. (even if it's proven to come from the same person)

A person I know had a problem with one-way output valve on a vital organ that outputs into the intestine, that one-way valve was malfunctioning, allowing bi-directional two way flow of the e.coli in the output to flow upstream as well, contaminating the vital organs one by one.

Anyway, it is NEVER safe to contaminate your food and water intake with your own body's solid waste output. Your stomach acids may not be equipped to neutralize that e.coli.

This is not the same thing as getting an immunization flu shot.

Edited by RogerDodger on 04/18/2014 13:56:24 MDT.

d k
(dkramalc) - MLife
Re: Re: Re: Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 14:31:21 MDT Print View

Getting any microorganism in a normally sterile site (blood, bladder, spinal fluid, etc.) is indeed very bad. But the GI tract is not normally sterile; we have a varied population of normal flora, and ingest bacteria when eating or kissing, just to give a couple of examples (and E. coli can be found in the mouth's normal flora, BTW, so swallowing one's own saliva may send E. coli through the upper GI tract and cause no problems). The lower GI tract is populated from the top down. Most organisms don't cause problems on their way through the tract, other than pathogenic (disease-causing) bacteria.

RodgerDodger, where was the malfunctioning "valve" in your friend? I'm guessing that somehow the "backwash" contaminated sterile areas of the body, if it reached "vital organs", perhaps through the bloodstream eventually? It sounds quite serious.

As I mentioned in the thread James cited, what medical microbiology teaches (at least when I went to school, and I'm not aware of any significant changes in thinking in this area since then) is that the mechanism of GI disease in normal healthy individuals takes place one of a couple of general ways. One may ingest pathogenic bacteria (E. coli O157:H7 serotype, Salmonella, Vibrio cholerae, for example) that either invade the intestinal mucosa or produce enterotoxins that make us sick. The other way is to ingest food that has been overgrown with bacteria that produce toxins (staph or Clostridium, for example). For more detail see: http://www.merckmanuals.com/professional/gastrointestinal_disorders/gastroenteritis/overview_of_gastroenteritis.html

All the references I've been able to find refer to the intestines as the target of these aforementioned disease process, as a result of *pathogenic* bacteria, not normal flora, and not in the upper GI tract (stomach, esophagus, mouth). It may be that ingesting a large amount of normal "garden variety" fecal flora may cause illness in a healthy individual, but I have seen nothing documenting that, what exactly the mechanism of such illness might be, or what quantity it would take to produce some sort of verifiable symptom. That's a study I won't be volunteering for, I can tell you!!!

Disclaimer: I don't consider myself primarily a microbiologist (though I did work briefly as one in a private reference lab) - rather I was a state-certified clinical lab scientist (mostly in hematology and immunohematology) in a hospital with a great microbiology department which saw pretty much everything under the sun, what with a large portion of the clientele being disadvantaged, homeless and/or immigrant: malaria, other exotic parasitic and bacterial diseases, you name it, we saw it.

Roger Dodger
(RogerDodger) - F

Locale: Wess Siide
Re: Re: Re: Re: Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 14:49:16 MDT Print View

re: dk
The infectious disease specialist couldn't be certain, but suspected malfunctioning "valve" near the bile, because the e.coli was creating expanding gas bubbles in the bile duct, caused abdominal pain. Eventually the infection spread to the blood stream and everywhere else. for about a week, specialist after specialist were playing Sherlock Holmes, guessing at the origin. At first thought it was Brie cheese sandwich haha!

With meds and many follow up tests, the culprit e.coli was cleaned out of the sterile organs and restricted to the downhill output factory.

d k
(dkramalc) - MLife
Re: Re: Re: Re: Re: Re: Re: RE: I probably have Giardia.. and it's no fun :-( on 04/18/2014 15:13:12 MDT Print View

I was guessing bile duct; that sounds like a terrible ordeal for your friend. I'm glad to hear that things turned out well in the end - whew!

Mark S
(gixer) - F
Dirtier water boil longer on 04/19/2014 08:37:32 MDT Print View

I think it also needs pointing out that IF the water is very dirty the boiling times suggested might not be enough.

If the Virus or bacteria is coated in debris it can act as pretty effective insulator.

For me personally i'll always err on the side of caution after being extremely ill from drinking contaminated water.

Years ago it took a lot of time effort and energy to clean water, now with current technologies and filters it's as easy as filling a bottle.

I've never been in a car crash on a public road where the impact was severe enough that a seat belt prevented injury.
Still i wear a seatbelt every time i sit in a car.

Unfortunately we do not know when and where we will require a seat belt, just like we cannot know just by looking at it if water is safe to drink.
We can play the odds using some common sense, but still you can't remove every risk in life.

David Drake
(DavidDrake) - F - M

Locale: North Idaho
Re: Dirtier water boil longer on 04/19/2014 11:20:51 MDT Print View

"...we cannot know just by looking at it if water is safe to drink."

But we *can* make reasonable assumptions by looking at surrounding conditions.

Turbid water at lower elevations, esp. near livestock areas? Foolish not to treat.

Clear, fast-flowing water at elevation in a wilderness area, and collected very near the source? Drinking without treatment is very low risk.

David Thomas's points about UV purification up-thread imply water within the first few inches of the surface of an alpine lake should also be safe.

I always carry an effective method of treatment, but if conditions suggest the water is very unlikely to be contaminated, I prefer not to treat.

Mark S
(gixer) - F
Re: Re: Dirtier water boil longer on 04/19/2014 12:37:52 MDT Print View

Clear or fast flowing water makes absolutely no difference.

Sure drinking out of a muddy puddle would logically tell us is riskier, but you can and people do get ill from drinking extremely clear, fast flowing water.
Hopefully someone can back me up or call me out here, but i'm sure i read a report that stated well oxygenated water is better for certain water based bacteria/virus?

True or not we are talking microscopic here, you really have absolutely no idea just by looking at the water if it's good or bad.


Don't get me wrong, we all make our own risk assessments in our lives on a ongoing basis, it's up to each of us to weigh up what we perceive to be the risk, form a strategy and act upon it.

My point is us humans tend to only accept the full force of our decisions if something goes wrong.
I'm a prime example, i was extremely cautious to the point of being anal about where i took my water from, i made fun of my mate who was treating and boiling his water, to me then it was a macho thing "look at me i laugh in the face of microscopic bacteria/virus"

I fell extremely hard from my high horse, having been through that i will do what ever is in my power to prevent it again, even IF it's a 1 in a billion chance.

With modern filtering your reducing the chances for no real gain in hassle and very little financial cost, so to me why wouldn't i filter all my water?

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Re: Dirtier water boil longer on 04/19/2014 13:53:23 MDT Print View

I think clear and fast flowing is correlated with few parasites.

If you did a survey of many water sources, those that were clear and fast flowing would be more likely to be on some mountain, near the source, less likely to be contaminated. Higher on a mountain there are fewer animals.

Those water sources that are slower and dirtier looking, are more likely to be downstream of animals pooping or whatever.

The parasites in water aren't visible and the fast flow of a stream does not kill parasites.

When I'm on some mountain and the water looks clean and it's fast flowing, I often don't treat it, and have never got sick that I know of. But the Squeeze is so convenient I've been treating more often. Maybe I've just been lucky in the past.

Some article on BPL talked about this.

David Drake
(DavidDrake) - F - M

Locale: North Idaho
Re: Re: Re: Dirtier water boil longer on 04/19/2014 14:34:04 MDT Print View

When (or if) backcountry water is safe to drink without treatment has been endlessly debated on these forums.

The key requirement for what I suggested was very low risk water isn't "clear" or "fast-flowing" but "at elevation in a [designated] wilderness area," (e.g. not the Appalachian Trail, or on rangeland); and "collected very near the source," (e.g., I know it's coming out of the ground without crossing human or game trails before the point of collection). Does that describe the water that made you ill?

"Clear" *does* mean the water has no algal or bacterial biofilms. "Fast-flowing" (if close to an underground source) *does* mean the water is likely to be as cold as it was coming out of the ground. It's been a long time since I had a food handler's card, but IIRC, cold temps inhibit the growth of pathogenic bacteria.

The risk of waterborne viruses in the American backcountry is virtually zero. And (again, IIRC) the organisms of most concern in backcountry water aren't bacteria, but giardia and cryptosporidium. The CDC says both parasites are spread by fecal matter--water under conditions where I would likely drink it untreated is *visibly* very, very unlikely to be contaminated by human or animal feces.

This isn't about being macho, or laughing in the face of danger, it's about rational risk assessment. It's also about cultivating a philosophical attitude that wild nature, while certainly indifferent to me, is not an actively hostile force I need always protect myself from. For me, an antidote to a "pack your fears" approach to wilderness is worth the (very slight) risk of drinking raw water under particular conditions. Others may make a different choice, of course.

I assume your "1 in a billion chance" remark was meant hyperbolically, since the best filters still won't get the last one out of every billion organisms in a contaminated source. And you'd have to drink "1 in a billion chance" raw water every waking second of your life to have even odds of catching anything.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Dirtier water boil longer on 04/19/2014 17:03:37 MDT Print View

"I think it also needs pointing out that IF the water is very dirty the boiling times suggested might not be enough.

"If the Virus or bacteria is coated in debris it can act as pretty effective insulator."



Water is an excellent conductor of heat. If the debris is permeable to water (like slime) it's going to be as hot as the water. As long as your water doesn't have massive floaters, you'll be fine.

What sort of hypothetical "insulator" are you imagining?

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: Dirtier water boil longer on 04/19/2014 17:12:50 MDT Print View

"David Thomas's points about UV purification up-thread imply water within the first few inches of the surface of an alpine lake should also be safe."

Has been my SOP for years when taking water from high altitude lakes in the Sierra. No problems so far. That said, there are high altitude lakes where horse packers have let their horses crap on the lake shore, and there I treat just to be sure. I don't know if horse manure is as pathogenic as cow manure, but I prefer prudence over being a guinea pig.

"I always carry an effective method of treatment, but if conditions suggest the water is very unlikely to be contaminated, I prefer not to treat."

+1 at the risk of reigniting The Great Rockwell Flame War. ;0)

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: Re: Dirtier water boil longer on 04/19/2014 17:17:46 MDT Print View

"you really have absolutely no idea just by looking at the water if it's good or bad."

True enough, but people can and do successfully assess the potablity of water by evaluating the surroundings.

Mark S
(gixer) - F
Some good points. on 04/19/2014 17:20:15 MDT Print View

Some good points.

While i agree a good filters isn't an absolute guarantee i don't think anyone could argue it doesn't dramatically reduce the risk.

Elevation may reduce the risk, if water rat has been running past the area your collecting water though, if a dead bird is a few meters upstream, dead fox, rabbit, they could even be frozen and defrosting upstream as you're drinking.

I've even seen campers swimming in mountain top lakes and streams, i've found evidence of people urinating into high streams and defecating.

I do agree that if given a choice i would prefer to drink untreated water from a fast flowing stream, rather than a muddy puddle, i personally believe from my personal experiences that the risks are higher than you believe they are.

As i say though unless we as humans experience something first hand we tend to discount logic and others experience, so i do understand.
A girl i used to work with contracted HIV by having unprotected sex, she she's she did it once and didn't push the point about using protection as she felt the experience would be better.
I'm not comparing getting a nasty stomach bug to contracting a deadly, life changing disease, just pointing out that nature doesn't care about what people want or have done before.

Sorry if i come off a bit preachy, that's not my intention, as i say we're all adults and we all carry out own risk assessments continuously.

It's just having been extremely ill from suspected water (yes it was taken from a high source, was clean and fast flowing) and with modern filters being so cheap and easy to use i just think even IF it only slightly reduces the risk it's crazy not to use one.

I respect your philosophy though and have no chance or intention of trying to change your mind, i have my fingers crossed i can get some folks to think twice and research the risks and solutions.

James Couch
(JBC) - M

Locale: Cascade Mountains
Hygiene on 04/19/2014 22:55:44 MDT Print View

There are a number of studies that indicate that many instances of gastrointestinal illness were as likely (if not more likely) to be caused by poor hygiene as by 'bad' water. It is always amazing to me to see the amount of folks folks who are completely anal about their water treatment routing but don't wash their hands before preparing or eating a meal, or wash their cookware afterwards!

d k
(dkramalc) - MLife
Re: Hygiene on 04/20/2014 02:34:49 MDT Print View

Jim, I'd be interested in reading those studies if you can list them, and where they might be found.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Hygiene on 04/20/2014 05:53:43 MDT Print View

Well, as far as scientiffically designed studies, I have only seen a few, but they do not count. They were done in hospital's on disease communication/vectors. Most diseases are studied that way.

It is nearly impossible to tell if water is safe to drink or not. Yes, you can evaluate the surrounding area. You can MINIMIZE your risk. Filters only minimize the risk. Chemicals, too. UV, and solar, also. Boiling is perhaps the safest. You are subjected to constant exposure to a lot of different bacteria all day long.

As DK said, I would be interested in any scientific studies and papers, also.

Washing cookwear? Well, I don't really do that either.I rinse it out with wild water, then I dry it out with my dirty bandana. I don't try to get it scubbed bright and clean. It is boiled every 10-14 hours, thats as clean or more so than at home. Bacteria and spores take time to form. Drying it out means most die because water was removed. It will take 24 hours for anything grow on it to the point of making me sick, even if I didn't rinse and dry it and made sure to leave it in a warm, dark place. I have eaten twigs and bugs in my water after boiling. I wouldn't say this is something to worry about. At least I haven't been sick from this yet. But this is not a scintific study by any means.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Re: Hygiene on 04/20/2014 07:41:59 MDT Print View

If you eat out of your pot you don't have to worry about it. Wash it off when done. When youu next use it and heat water in it, it will be disinfect it.

Of course there's your spoon - wash it off so there's no organic matter, then the next time you stir up your hot food in boiling water it will disinfect it.

Buck Nelson
(Colter) - MLife

Locale: Alaska
Water, hygiene and more on 04/21/2014 05:30:23 MDT Print View

One of the very best studies is "Medical risks of wilderness hiking"

http://www.ncbi.nlm.nih.gov/pubmed/12681456

METHODS:
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...

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.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Water, hygiene and more on 04/21/2014 09:52:29 MDT Print View

"The risk of gastrointestinal illness can also be reduced by maintaining personal hygiene practices and cleaning cookware."

That Is the common belief, but has it really been tested?

As mentioned above, What can grow in a pot overnight that doesn't get resolved with the next boil?"

And from what "d k" has said, anal-to-mouth self-infection hasn't been substantiated.


Personal hygiene and cleanliness in the kitchen seems like common sense, but the question of it's effectiveness is still in question.

Edited by greg23 on 04/21/2014 09:56:37 MDT.

Marko Botsaris
(millonas) - F - MLife

Locale: Santa Cruz Mountains, CA
Re: Re: Water, hygiene and more on 04/21/2014 10:01:22 MDT Print View

I always assumed this meant inoculating your food with the bugs from dirt you picked up on the trail.

Greg Mihalik
(greg23) - M

Locale: Colorado
Re: Re: Re: Water, hygiene and more on 04/21/2014 10:32:41 MDT Print View

My food is in my pack, in bags, until it get dumped into boiling water.

You got ham hock swinging from your pack?

;-)


Oh, you mean dirty hands handling the food....

Well maybe washing away tetnus Is a good idea.

Tetnus
Muscular spasms (specifically opisthotonos) in a patient suffering from tetanus.
Painting by Sir Charles Bell, 1809.

Edited by greg23 on 04/21/2014 10:36:46 MDT.

d k
(dkramalc) - MLife
Re: tetanus on 04/21/2014 17:33:01 MDT Print View

Did you read the same article I did, Greg? It had that picture too...

"Clostridium tetani is the causative agent of tetanus. ... Carrier rates in humans vary from 0 to 25%, and the organism is thought to be a transient member of the flora whose presence depends upon ingestion. The disease stems not from invasive infection but from a potent neurotoxin (tetanus toxin or tetanospasmin) produced when spores germinate and vegetative cells grow after gaining access to wounds. The organism multiplies locally and symptoms appear remote from the infection site."

So in other words, you should wash your hands to keep tetanus out of your wounds (more important than keeping it out of your food! though if you keep it off your food it's less likely that you will be carrying it inside you to a later date when you will have additional chances of getting it in your wounds). My thinking (this is opinion, haven't seen this spelled out anywhere) is that handwashing on trips is probably more important in terms of washing away any disease-causing organisms you've picked up externally, and perhaps to keep any of your own internal flora from getting into foods like cheese that you carry for a number of days that can foster bacterial toxin production. Also to keep your internal flora away from your companions in case you are incubating a disease-causing strain of bacteria, or even a cold (adenoviruses and others are shed in feces too).

Valerie E
(Wildtowner) - M

Locale: Grand Canyon State
RE: Re: tetanus on 04/21/2014 17:57:41 MDT Print View

And getting a tetanus shot (or a booster) is probably a pretty good idea, too...

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: RE: Re: tetanus on 04/21/2014 18:02:27 MDT Print View

"And getting a tetanus shot (or a booster) is probably a pretty good idea, too..."

+1 big time! All the washing in the world isn't going to prevent tetanus being carried into a puncture wound, which is the way a lot of tetanus infections used to be incurred, stepping on a nail, thorn, etc.

d k
(dkramalc) - MLife
Re: RE: Re: tetanus on 04/21/2014 19:08:25 MDT Print View

+1 on the vaccine! I should have said that...

Daniel Pittman
(pitsy) - M

Locale: Central Texas
Re: Re: tetanus on 04/21/2014 20:32:37 MDT Print View

I had tetanus once. It's no joke. Went to the doctor with a sore throat and back spasms. Diagnosed with strep throat, and about to be discharged when a violent back spasm hit. The doctor said, "Hold on a minute, let's do one more test..." then stuck a tongue depressor in the back of my throat. I chomped down so hard it made the doctor jump! Apparently, a symptom of tetanus is that your gag reflex is replaced by a chomp reflex.

Treatment was pretty easy, IV antitoxin, oral antifungal, and a big-ass bottle of Valium.

The doctor asked if I had been exposed to rusty metal, or had any puncture wounds. I said, "I'm a bicycle mechanic, so yeah. Every damned day!"

John S.
(jshann) - F
Re: I probably have Giardia.. and it's no fun :-( on 04/24/2014 17:15:16 MDT Print View

No mention of confirmed diagnosis.

James Couch
(JBC) - M

Locale: Cascade Mountains
Re: Hygiene on 04/24/2014 20:15:25 MDT Print View

In addition to the study Buck noted upthread here are a few more:

http://rendezvous.nols.edu/files/Curriculum/research_projects/Risk%20Management%20Reports/Medical%20Incidents%20and%20Evacuations%20on%20Wilderness%20Expeditions.pdf

http://www.ijidonline.com/article/S1201-9712%2800%2990102-4/abstract

It is also good to note the Cryptosporidium can lso cause simimilar gastro distress and crytpto can survive outside of water for much longer periods of time than does Giardia, including on your hands after being around infected water.

Kevin Burton
(burtonator) - F

Locale: norcal
Follow up... on 04/27/2014 10:59:12 MDT Print View

Hey guys. So just a follow up here.

After about 1.5 weeks I was better. NO official diagnosis. For various reasons the logistics around getting an official diagnosis were somewhat complicated.

I went on Metronidazole and within 72 hours I was fine. Well, much much better.

http://en.wikipedia.org/wiki/Metronidazole

Symptoms were severe lethargy, bloating, LOTS of burping (like non stop), green stool, and loss of appetite. I didn't really eat for a good 2-3 days. Normally about half the volume of food per day.

One trick I learned to make me feel better was just to rock back and forth from a horizontal to vertical position. That helped with gas and bloating.

Definitely NOT fun. Screwed up my plans as well as I was going to go back to the woods.

My doctor felt pretty confident that the burping and green stool were giardia so he just gave me meds without the test. I didn't ask him but apparently they are somewhat pricey and since he felt confident I figured I would save the money.

John S.
(jshann) - F
Re: Follow up... on 04/27/2014 13:52:55 MDT Print View

Thanks for the follow up Kevin. Glad you are better. I'd imagine many cases of suspected giardia are treated with meds and no lab test to confirm.

David Thomas
(DavidinKenai) - MLife

Locale: North Woods. Far North.
Re: Re: Re: tetanus on 04/27/2014 15:55:19 MDT Print View

>"The doctor asked if I had been exposed to rusty metal, or had any puncture wounds."

Rusty nails are kind of a red herring. It's not that the tetanus bacterium Clostridium tetani is a iron-oxidizing species (there are iron-oxidizing bacteria, but no human pathogens that I know of). But rusty metal has been in moist conditions, often in the ground, and can be sharp and strong enough to cause a deep (anaerobic) puncture wound. And rusty metal has a lot of small pores and therefore more potential for delivering bacteria deep into your tissues. So, yes, many people have gotten tetanus from a "rusty" nail, but any fomite (an inanimate object that transmits an infection) could serve that purpose if it had been exposed to soil containing the bacteria (soil with livestock manure is even higher risk).

Cameron Habib
(camhabib) - F
Some random information on 04/30/2014 21:00:47 MDT Print View

Quite a lot of information in this thread, some of it good, some of it bad; hopefully I can help to shed a bit of light. To preface, I’m a molecular microbiologist, with particular focus on infectious and emerging disease - in simple terms, I perform the type of research those CDC reports are based on. Some quick notes I typed up, hopefully someone finds this of use or interest.

There are two basic categories, and several subcategories, of contaminants you should be concerned with when it comes to drinking water:

1) Biologicals

1.1) Viral - Viral contamination is extremely prevalent in nature. Thankfully, most of these viruses are known as bacteriophage, and infect only prokaryotic (bacterial) cells. These cannot infect eukaryotic organisms (for reasons I can specific if anyone is interested), and as such, pose little threat to human life. Little does not mean none however. As humans, we are inhabited by thousands to millions of different bacterial species, many of which, while symbiotic in nature, are only a handful of genes away from virulence. The perhaps best known example of this is one of the most common soil bacterias, present in almost all human gut micro biomes, Bacillus subtilis. With the addition of a few very well known and studied genes, it quickly goes from a harmless organism, to something called B. anthracis, which many of you will recognize as the infamous bioterrorism agent. While unlikely the necessary genes could be transferred via bacteriophage (called horizontal transfer) for this kind of change to occur, it isn’t impossible. Some caution should be taken against viral contamination to prevent mutation of human flora and microbiome mutations resulting in increased virulence.

Depending on the nature of the viral strain, boiling can be insufficient to destroy. DNA damage (due to UV light or other method), chemical reagents (bleach), biological reagents (proteolysis), and in some cases autoclaving (pressurized super heated water) are the only options for sterility. As viruses are smaller than the filter pore size of 0.2uM, these devises are ineffective against viral particles. Your best defense against these in the field would be a UV pen or chemical agent.

1.2) Bacterial / Protozoa - It is a commonly held standard that a pore size of 0.2uM is sufficient to filter out biological contamination from liquid samples. When preparing chemical solutions in a research lab, a filtration device with this pore size will be used to sterilize material sufficient to achieve reaction grade biologicals. While there do exist both bacterial cells (known as ultramicrobacteria) as well as bacterial spores smaller than 0.2uM, though not Protozoa to the best of my knowledge. These are generally uncommon however, and to the best of my knowledge, none of yet to be identified with mammalian pathogenicity.

Heat is often enough to kill most biological samples, though boiling (as defined for this purpose to be at 100C though does change with pressure) can be insufficient in some cases. One of the most important bacterial species in science, Thermus aquaticus, part of a group of organisms known as thermophiles, thrive in high temperatures, often in excess of 80C. Other species of this group have been observed to tolerate up to 122C for extended periods. As someone previously mentioned, it is not only the temperature, but the duration of time as well that determines survivability for organisms. Any good molecular gastronomy cookbook (Modernist Cuisine being my favorite) will have kill curves showing time plotted against temperature to determine the correct conditions to adequately decontaminate (not sterilize) material. Chemical agents will have a similar effect as heat, with most being easily effected, but some having limited efficacy. Bleach is the most common compound used in laboratory settings, though some species can survive for prolonged periods in high concentrations of chlorine. Those are again rare, but highly pathogenetic when encountered.

Typically speaking, 30 minutes at 121C is considered sterile for liquid samples. For common drinking water contaminants, contaminants should be killed fairly quickly at 100C; exact times and temperature are of course entirely dependent on what you're trying to kill though. Keep in mind however, bacteria that posses the ability to infect a mammalian host, which an internal body temperature somewhere around 36C, are optimized to grow at that temperature (which is why they choice the human as a host), and are unlikely to be able to survive a wide enough range of temperatures to including 100C for any amount of time.

1.3) Protein based - These are the deadliest of all, and least common. Formally known as “prions,” these are mis-folded proteins, that upon contact with normal state proteins, auto-induce their transition to disease state. Prions are virtually impossible to remove by filtration, due to their small size, unaffected by heat, due to their hyper-stable state, and often cannot be dissolved by chemical means. There are reports of one of the more famous prions, bovine spongiform encephalopathy (otherwise known as Mad Cow), infecting a farm with farmers reacting by killing the cows, burning the property, and abandoning it for decades, only to come back and find the prion still exists. There is no cure, no test for contamination, and no real way to remove them via field or even lab setting. Current protocols call for several treatments of gaseous solvent to be passed over the contaminant, along with a number of other measures, and even then, many have proven ineffective.

2) Non-biologicals

I won’t go into great detail here, but this category includes everything from toxins produced by biological threats (such as the toxin produced by Clostridium botulinum), to nerve agents, poisons, etc. These can typically be filtered out by activated charcoal, or other distillation methods.

Now, all this said, the best thing to do is just practice common sense. How likely are you to encounter a prion from a clear moving spring along the cost of Maine? How safe is that water just outside the cattle farm to drink? What are the contaminants most common in that area, and where are they typically found? I personally rely on three purification techniques, in this order: a 0.1uM filter (Sawyer Squeeze, not mini), UV SteriPen, and chlorine dioxide (Aquamira). Between the three of them, they can neutralize almost any pathogenic biological contaminant, and certainly all of the more common ones. If a water supply looks clean and unpolluted, I simply use the filter. If I’m unsure, or want extra protection, I treat with UV for a bit, or chlorine dioxide if the volume is larger. Be safe, use common sense, and you should go home happy and healthy.

Michael Gunderloy
(ffmike) - MLife
Re: Some random information on 05/01/2014 05:51:11 MDT Print View

Thanks for the informed info!

"a 0.1uM filter (Sawyer Squeeze, not mini)" - Why the Squeeze over the Mini?

Has there been any work done in looking at the overall geographic distribution of viruses harmful to man? Wondering if there are regional or seasonal differences that would make it more or less likely to run into viral contamination of water.

Cameron Habib
(camhabib) - F
Re: Re: Some random information on 05/01/2014 08:00:48 MDT Print View

I prefer the standard size as the Mini has less filtering surface area. This reduced area causes the filter to become more easily clogged, causing increased pressure and strain on the pores, which could cause damage, and as a result, allow for microorganisms to pass through. The number of cells required for pathogenicity by certain species of bacteria can be amazingly small, and as such, even a minor defect in a filtering apparatus can have drastic impacts. In short, it's a type of insurance policy.

I'm not sure about the distribution, as that would be more of a Public Health matter, though I'm sure it has been mapped out before.

Buck Nelson
(Colter) - MLife

Locale: Alaska
Giardia information sources on 05/01/2014 09:49:36 MDT Print View

I find the NOLS information very interesting because they are engaging in outdoor activities like us and seem to keep some good records. Thanks for the link, Jim. I'd like to note that NOLS has shown that water treatment, hygiene and clean cookware has yielded outstanding results for gastrointestinal health.

The conclusions of the oft-cited Welch paper are NOT accepted by the CDC, FDA, EPA, Mayo clinic or any other major public health organization of which I'm aware. I've outlined some of the reasons his paper has been refuted by mainstream science.

Backpacker Giardia: Debunking a Skeptical Paper

The CDC has one of the best overviews of giardiasis, including prevention.

The EPAs Giardia: Drinking Water Health Advisory is a good source of information for both underlying data and studies as well as conclusions. It has information on the prevalence of giardia cysts in backcountry water, the effectiveness of chlorine and other forms of disinfection, immunity, and many other oft-discussed topics. Well worth a read-through for those interested in the topic!

Edited by Colter on 05/11/2014 23:38:38 MDT.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Giardia information sources on 05/01/2014 09:52:05 MDT Print View

I assume you don't mind if I post a link to your site elsewhere

Buck Nelson
(Colter) - MLife

Locale: Alaska
Re: Re: Giardia information sources on 05/01/2014 10:07:00 MDT Print View

That would be fine Jerry.