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Giardia Outbreak
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Roger Dodger
(RogerDodger) - F

Locale: Wess Siide
Re: Backpackinglight: Where people actually talk science on the internet! on 11/11/2013 11:08:04 MST Print View

very informative.
I'd like to add that aside from environmental and behavioral habits, the biggest elusive variable is the immune system.

This married couple I know. He's a generic Caucasian American grew up on clean city US water, he married a Eurasian woman from one of the poor dirty places in west Asia.

They went to Mexico for their anniversary. Ate the same food, drank the same water.
He got violently ill, but as irony would have it, her immune system was rock solid. Presumably because she had been exposed to polluted water in her birth country and her immune system is resilient to the microscopic bad boys.

Edited by RogerDodger on 11/11/2013 11:08:45 MST.

Phillip Asby
(PGAsby) - M

Locale: North Carolina
Interesting on 11/14/2013 08:40:32 MST Print View

I am a newbie - and I hauled water and or used an MSR miniworks - with good results. Have a steripen but haven't used it due to my aversion to floaties - haven't solved that one yet although it isn't that hard to do (just hadn't done it... mostly need a scoop system or something to prevent contamination of the bottle itself...). Just got a Sawyer Squeeze to use this weekend - it sure is smaller and lighter than the MSR...

All this stuff can drive you crazy - but I've had salmonella twice and have no desire whatsoever to get Giardia - the salmonella was awful and I can't imagine what Giardia would be like. So I treat - wash my hands a lot and wash my utensils - and make my Scout son do the same. Just not worth it - I'll suck up the weight and save elsewhere to have safe water.

As for individual immunity years ago I travelled to the Soviet Union. Of the 6 cities we visited only one had arguably safe drinking water from the tap (Moscow). Leningrad in particular had a parasite which all natives were immune to - but anyone not raised there would get sick as a dog from the water. I used iodine tablets for suspect water but it was trickier than you'd think avoiding all water - no fresh veggies for example - ice cubes - etc...

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

Locale: Silicon Valley
Re: Interesting on 11/14/2013 11:43:01 MST Print View

"I can't imagine what Giardia would be like."

For the first week, I was afraid that I was going to die.
For the second week, I knew that I was going to die.
For the third week, I was afraid that I was not going to be able to die.

It affects everybody a little differently. It was once thought that 50% of healthy adults were asymptomatic. To some, it seems like a transient episode of diarrhea, and then it is gone. To others, it seems to get worse and worse, especially if a proper diagnosis can't be made.

--B.G.--

Justin Baker
(justin_baker) - F

Locale: Santa Rosa, CA
Re: Interesting on 11/14/2013 11:47:57 MST Print View

"Have a steripen but haven't used it due to my aversion to floaties"

Have you tried using a bandanna to filter out floaty stuff?

Larry Swearingen
(Larry_Swearingen) - M

Locale: NE Indiana
Public Restrooms on the way to a Hike ? on 11/14/2013 15:10:58 MST Print View

I think that if you treat your water (I've always filtered) you
stand a better chance of getting some sort of bug from the Gas Station
restroom that you use on the way to and from your hike.
Think about it. You wash your hands after using the facilities but
then you grab the door handle to open the door on the way out.
How many people have grabbed that same handle that day before you ?
How many of them washed THEIR hands before leaving ?
If you can get Giardia from a companions unwashed hands while backpacking then you can certainly get it from a Public Restroom doorknob.

Larry

on edit: I agree with the poster that talks about fear mongering.
Talk of Giardia will not keep me away from hiking. When I hiked in the CA Sierra in the 70's we never even heard about that stuff. I'd
just dip my cup into any stream and drink.
I used to work with a guy who after using a public restroom would take a paper towel to shield his hand to open the door, then drop the paper towel on the floor as he left. I always thought he was a pansy A-Hole for that.

Larry

Edited by Larry_Swearingen on 11/14/2013 15:27:02 MST.

Dale Wambaugh
(dwambaugh) - MLife

Locale: Pacific Northwest
Re: contaminated backcounrty water on 11/14/2013 16:14:29 MST Print View

I have one friend who got dysentery from a campground water spigot. In the US, we assume that if the water is coming out of a pipe, it is okay to drink. Not always. I wonder how many cases come from sources like this. Giardia has been found in municipal water systems as well.

I treat my water using a filter and use chemicals or boiling as the backup and I try to be careful to not cross-contaminate. All you can do is try.

Randy Cain
(bagboy) - MLife

Locale: Palmdale, CA
Hygiene on 11/14/2013 16:16:19 MST Print View

On a slightly different note, I never hear anyone talk about the issue of spores and hand sanitizers. Clostridium Difficile (c-diff) is a bacteria that’s a real nightmare in hospitals and causes diarrheal illness that can and does kill people. The patients who have known cases of this in the hospital are isolated for it, meaning that signs are placed outside of their rooms indicating that not only are gowns and gloves mandatory in the patient's room for staff and visitors, but that the hand sanitizers that are outside of every door are NOT effective, because the c-diff is transmitted in a spore form. So the bottom line is that if you get c-diff spores on your hands, hand sanitizers do nothing, because the nastiness is encased in a hard little protective spore that doesn't break open until it is in your intestinal tract. Some hospitals will actually take the hand sanitizer OFF of the wall dispenser entirely as a reminder that the only way to deal with the spores is to wash with soap & water. The reason I mention all of this is that as many folks on here know, giardia and cryptoSPORidium are transmitted by……spores. Yet how many times do we hear about people carrying hand sanitizer? I suppose there’s nothing wrong with carrying it, as long as they understand that it won’t do a thing in the prevention of spore-transmitted funk. So if you're one who believes that these diarrheal illnesses that folks get on the trail are transmitted by poor hygiene, and you want to improve YOUR hygiene in order to avoid it, hand sanitizers are NOT the way to go. Bummer!!

Edited by bagboy on 11/14/2013 16:16:53 MST.

Kevin Schneringer
(Slammer) - MLife

Locale: Oklahoma Flat Lands
Cross contamination on 11/14/2013 16:28:40 MST Print View

This past weekend my hiking buddy asked why I carried soap in my hip belt pocket. I told him to clean off before lunch.

After he filtered water and ate lunch at our water stop I pointed out his cross contamination sequence.

He filtered water
Then washed his knife and hands in the water and then sliced and ate his bagel.

I let him know he could shave his pack weight by 11 oz if he ditched his filter. He asked me how?

Off course you can figure that out....:)

Randy Cain
(bagboy) - MLife

Locale: Palmdale, CA
immune system differences on 11/14/2013 16:57:44 MST Print View

All that being said about the nasty spore-transmitted c-diff in hospitals and long-term health care facilities, it actually poses very little risk to individuals with a healthy immune system. It’s the immunocompromised folks that suffer the morbidity and mortality effects. I’ve worked in hospitals for years with these patients and have probably inadvertently consumed 10 million spores…give or take 3. ;) Yet I’ve never had a c-diff infection, and neither has any of my coworkers. So it makes me wonder how much a healthy immune system plays in whether or not we become symptomatic after consuming X number of spores from giardia or crypto.


Cross-contamination brings up questions too. If it's true that the solution to pollution is dilution, then I think the question is, "Did your cross contamination introduce enough spores that your immune system can no longer deal with them?" When the literature says that as little as 10 spores can cause infection, does that mean in a healthy individual with a badass immune system? How is the strength of the immune system of those involved in the study even measured? It's not, so it just means that in the individuals involved in a study, there was some particular individual that consumed 10 spores and got sick. It's like reading the list of possible side effects of a medication. They are listed because someone at some point in the past had that effect. But what's the true likelihood that YOU will have that effect? Maybe the dose of spores left behind after someone washes their spoon in the creek and dries it off are extremely tiny compared to the number of spores present in the liter of water that they just slammed down at the end of their hike. It only makes sense that the likelihood of infection is dose dependent in relation to each individual's immune system. I'm sure I can consume some unidentified number of spores and be just fine. Maybe for me the drops of water in the threads of my water bottle don't contain enough spores to even worry about. But maybe the entire liter or two of water does.

Edited by bagboy on 11/14/2013 17:41:11 MST.

Buck Nelson
(Colter) - MLife

Locale: Alaska
Immune sytems, infective dose, etc on 11/15/2013 06:08:35 MST Print View

Good thoughts people. Randy, I like the way you don't start with the conclusion and work your way backwards!

As far as testing for the infectious dose in humans, that has only been done once and it was a very limited study. There's a graph of the results about 1/5 of the way down this page

There is a good paper on giardia risk assessment and including formulas for the infectious dose (about 2% for one cyst) and a good discussion on the many variables, many of which are poorly defined.

Since there is so much we DON'T know, I think it's important to focus on what we DO know.

For example, regardless of the source, we know that Published reports of confirmed giardiasis among outdoor recreationalists clearly demonstrate a high incidence among this population.

So what's different in the outdoors? All things being equal I'd expect giardia to be more common in more population dense areas where hygiene standards are relatively lax. Giardia is in fact common in child care centers.

Population density tends to be very low on backpacking trips, though. So if we normally come in contact directly or indirectly with orders of magnitude more people in our "normal lives" what's the difference? Dirty hands? The only study of it's kind found hiker's hands were cleaner at the end of their hike.

Giardiasis is well-known as a waterborne disease. How about the water? According to the EPA Cysts have been found all months of the year in surface waters from the Arctic to the tropics in even the most pristine of surface waters

But how about the famous quote neither health department surveillance nor the medical literature support the widely held perception that giardiasis is a significant risk to backpackers in the United States? Well, it's not true. He designed a study to get the results he wanted. Statements by that author have been specifically refuted by the CDC.

The link above quotes several papers showing a correlation between not treating backcountry water and giardia.

Clean hands and clean water maximize or odds of staying healthy at home and in the field. That said, treating water is still a matter of personal risk assessment.

Edited by Colter on 11/15/2013 07:10:22 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Hygiene on 11/15/2013 15:14:23 MST Print View

> if you're one who believes that these diarrheal illnesses that folks get on the
> trail are transmitted by poor hygiene, and you want to improve YOUR hygiene in
> order to avoid it, hand sanitizers are NOT the way to go.

I am going disagree quite strongly here with the way this has been phrased. I think it is simply wrong.

The most common cause of diarrheal illnesses is simply e Coli from not washing after going to the toilet. Sure, there are hordes of other wogs around, but e Coli is the one most likely to get you.

What does washing do? Basically, it physically washes the bacteria off your hands before it gets to your mouth. A little soap helps as a wetting agent.

Cheers

Randy Cain
(bagboy) - MLife

Locale: Palmdale, CA
Hygiene on 11/16/2013 00:29:58 MST Print View

Roger,

I’m not entirely sure what you’re disagreeing with when you quote me. The title and context of the thread is giardia, so that’s what I was referring to when I talk about diarrheal illness, although I threw crypto in there because it’s also spread in spore form. I don’t disagree at all about e. coli being a more common cause of diarrheal illness, but that's not what this thread was even about. My point was that hand sanitizers aren’t effective on spores (c-diff, giardia, crypto). And the entire US hospital system doesn’t feel that the hand sanitizers are effective on e. coli either, because they are all very firm in their stance that these sanitizers are not to be used after going to the toilet or before eating and that washing with soap and water is the only appropriate action. That's not to say that the US hospital system is always right (I argue with them all the time), but that’s their stance nevertheless.


Cheers


PS: This thread is older than I thought, and I just realized that I had already posted about hand sanitizers and spores about a year and a half ago on this same thread. My apologies for the redundancy. There’s good info here though, and my thanks to Buck for all of the great links!!! I find it very valuable to be able to see the sources of information for myself.

Edited by bagboy on 11/16/2013 00:58:24 MST.

d k
(dkramalc) - MLife
Re: Re: Hygiene on 11/16/2013 01:28:16 MST Print View

Roger,
Are you saying that one gets sick by not hand washing and therefore ingesting the E. coli that one just excreted? Maybe I'm misunderstanding, but that is what it sounds like you are saying. I will agree that someone can infect another person with either an enteropathogenic strain of E. coli or a strain that is new to the second person that will initially cause illness (as in Montezuma's revenge), but so far as I know, and colleagues more illustrious in the field of microbiology than myself have confirmed, if it didn't make you ill before it came out of your gut, it's not going to make you ill the second time through.

Edited by dkramalc on 11/16/2013 01:56:26 MST.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Hygiene on 11/16/2013 02:33:24 MST Print View

Hi Randy

Yeah, could be we have been talking past each other here, and my lack of understanding of Americanisms is visible. My apologies.

You see, we don't really have/use 'sanitisers' here in Australia, so I assumed you were just talking about 'washing hands'. Assumptions are dangerous! To be clear and honest, I don't know much about 'sanitisers' and what they can or cannot handle.

Whe I come back from going to the loo in the evening, after cooking dinner in the tent, I find Sue waiting for me with a (mini!) bar of soap and some water. Hard line rule, and it works just fine.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Hygiene on 11/16/2013 03:31:00 MST Print View

Hi d k

> one gets sick by not hand washing and therefore ingesting the E. coli that one just excreted?
Yes, exactly that.

I am going to disagree with the rather simplistic image presented by the concept of 'the second time through'. For a start, (to the best of my knowledge), the path 'stomach-upper intestine-lower intestine' is a strictly one-way path. You have bacteria in your intestines you would never want in your stomach, but you are at no risk there. Stuff does not go backwards (upwards). The hazard, as far as I understand it, is moving the e Coli to a higher place in that path by the oral route.

Now, my knowledge may have been rendered out of date by the latest medical research. This is always possible. If so, references please! Preferably open literature, because I am retired and no longer have institutional access to the commercial journals.

Cheers

Randy Cain
(bagboy) - MLife

Locale: Palmdale, CA
Roger.... on 11/16/2013 06:49:31 MST Print View

Thanks for the clarification, Roger. That bar of soap you mention seems to be more effective than anything else and apparently trumps the alcohol-based hand sanitizers we have here provided that the hands are washed for a long enough time.

d k
(dkramalc) - MLife
Re: Re: Re: Re: Hygiene on 11/16/2013 10:39:17 MST Print View

Hi again, Roger -

My main "reference" is an esteemed clinical microbiologist of some 30+ years of experience and education in the field, an author of some nationally recognized studies in the infection control area. I placed the question to him some time back after one of these discussions periodically surfaced on BPL, and at that time he seconded the ideas I relayed in my previous post. I trust the depth and breadth of his knowledge greatly. However, if you have references to the contrary I'd be interested in reading them, and passing them back his way.

My other reference would be any standard medical microbiology textbook. Unless something has changed since I studied the subject, there are two main mechanisms of gastrointestinal illness. One is by the ingestion of enteropathogenic bacteria which colonize the intestines and either produce enterotoxins (normal garden variety E. coli is not one of these, but the enteropathogenic O157:H7 serotype is, as are Salmonella and Vibrio cholerae) or penetrate the intestinal mucosa (Shigella and Campylobacter, for example). The other is to ingest food which has been overgrown with toxin-producing bacteria such as Staphylococcus or Clostridium; in those cases the bacteria don't directly infect the intestinal lining, but the toxins act upon your body in nasty ways.

I can find no reference to any mechanism of normal E. coli acting on the stomach, or causing problems from ingestion (other than the obvious "yuck" factor!).

It may be "simplistic", as you say, to assume that we are not normally consuming small amounts of bacteria on a daily basis, normal E. coli probably being one of the more common as you can find it nearly everywhere if you just set out a Petri dish. That, after all, is how we originally get our gut colonized after birth (from the top down), normally with no ill effects.

However, I am still in favor of vigorous hand washing, make no mistake about it; it is a fine way to avoid spreading disease, introducing pathogenic bacteria from the environment to one's system, or transferring bacteria to food where it may proliferate.

Cheers,
dk

Edited by dkramalc on 11/16/2013 11:43:48 MST.

James Marco
(jamesdmarco) - MLife

Locale: Finger Lakes
Re: Re: Re: Re: Re: Hygiene on 11/16/2013 11:27:31 MST Print View

dk,
I agree, though, I am not a microbiologist, just a couple years of study many years ago. The basic "you cannot catch something from yourself" rule is about what I follow. e.Coli is one that has thousands of strains, one of the reasons it is used for reseach. All of these are social diseases or from the enviornment.

But, as you say, keeping bacteria out of your food is always a wise precaution.

Jennifer Mitol
(Jenmitol) - M

Locale: In my dreams....
Re: Re: Re: Re: Re: Re: Hygiene on 11/16/2013 11:53:41 MST Print View

One thing you guys are forgetting is what happens if a general surgeon nicks the intestine during surgery? You guessed it...serious infection. Because the bacteria leaking out of the gut are not meant to be in other parts of the body.

Yes, you CAN infect yourself with your own intestinal bacteria.

Where's Dean the general surgeon when you need him?

d k
(dkramalc) - MLife
Re: Re: Re: Re: Re: Re: Re: Hygiene on 11/16/2013 12:00:54 MST Print View

Of course you can infect yourself with normal flora in normally sterile sites, like nicking the gut and leaking bacteria into the bloodstream. I'm not forgetting it, it's just not part of the hand-washing reasons.

E. coli is not uncommonly found in the mouth as normal flora (about 25% of individuals, according to http://textbookofbacteriology.net/normalflora.html).

Edited by dkramalc on 11/16/2013 12:10:32 MST.