Giardia Outbreak

The Aquamira drops make no claim to being effective against Giardia or Crypto, as opposed to the tablets, which DO make such claim right on the package. But the drops also only require only a 15-30 minute contact time, whereas the more concentrated tablets require up to 4 hours in order to deal with the Giardia and Crypto.

The majority of folks that use Aquamira on BPL seem to be using the weaker liquid and wait at least 15-30 minutes (per the instructions), AND they generally don't seem to be reporting that they got sick. In threads about giardia and crypto, folks routinely say things along the lines of, "As long as I've treated my water with the drops, I've never gotten sick."

But is it safe to assume that since they weren't using a product proven effective against the cysts at the short, recommended contact times that the reason they didn't get sick was NOT because of the efficacy of the product but rather because there wasn't any Giardia or Crypto in the water to begin with? Am I off base here?

Katadyn MicroPur tablets were EPA registered as soon as they hit the market back in abouts 2005 or so. Aqua Mira drops were around before that time, but have only been EPA registered in the last couple of years. In the past it was thought that the MicroPur tablets were double the strength of the AM drops, but that may not be the case.

No difference in concentration between Aquamira drops and tabs. Here's a link to the thread where Dan Durston reiterates this, and links to a letter from Aquamira COO (also posted on BPL forums) spelling it out in detail:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=59824&startat=20

I stand corrected, so thanks David for that info. I had gathered that there was a concentration difference between the liquid vs tabs from other threads on BPL, which I'm sure you've seen.

I would submit, that there is a combination effect, also. You may have some partial resistance. Soo, things like 5 or 6 gardia organisms do not effect you. If you have a weaker digestive system, your partner may contract it. Difficult to verify anything, especially when there is quite a long and variable incubation period.

Different varieties of the same organism will effect the onset of a disease. Some will react strongly within four or 5 days and sick for 4 weeks. Some will be a little loose for a day. Difficult at best to diagnose and establish. There are too many variables. IFF it becomes of fatal or serious consequnces, there will be an EPA investigation…if they have the money, ha, ha. Our parks, waters and other lands are being raped in the name of the economy.

Perhaps this could be helpful,http://www.cdc.gov/healthywater/drinking/travel/backcountry_water_treatment.html

Mitch, nasty stuff and I'm glad you brought it up.

I've never had Beaver Fever, at least from the water to my knowledge, but I have had a gnarly C.Dif infection that nearly ended rather poorly for me. Similar to Giardia, this one's a cystic infection (mentioned above) and one of the keys to combat it, before and after antibiotics like Flagyl or vancomycin are used to kill them off, is the introduction of gut flora like the stuff you're taking.

I still regularly ingest probiotics in "regular food", like kefir and other such stuff, and in supplements like Yakult, because I have great incentive to prevent a reinvigoration of the cystic infection. There is genuine science out there to the effect that our immune system is much more resistant to cystic infections when we've got a gut full of the right flora, so I recommend family and friends who are backpacking to use probiotics in preparation for their trip, presuming they don't do it regularly already.

It's not a bulletproof shield, but having vibrant intestinal flora is proven to improve our bodies' ability to combat water- and food-borne illnesses. Guys like you, who've had Giardia, give good reasons why it might be better "to be safe than sorry".

You know I have been taking acidolpholus for years in massive doses and perhaps that accounts for the fact the my case of giardia was milder than I could have expected. Who knows, but I do agree that I seem to be a healthier person for taking it regularly and certainly during and after this case of giardia.Often when you take antibiotics you end up with diarhea and/or constipation. I never have.

Unless you are drinking out of mud puddles like my dog, I think direct person to person
transfer is more common in North American.

Follow your Grandma's advice. Wash your hands after the toilet and before you eat.
Giardia doesn't require the incysted form to be shared.

"An outbreak of giardiasis was investigated in one urban day care center; another day care center was selected as a control. In the study day care center, 35 per cent of the children were infected. Infection was spread to at least one household contact of 47 per cent of the infected children. The data suggest person-to-person transmission of giardiasis and the need for measures to prevent its dissemination. Early recognition and treatment of Giardia lamblia infections in children may be indicated."

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1646578/

I realize this is an old thread but since this topic is something of a hobby of mine I’d like to add a few points.

To the OP, I don’t doubt there are upticks and down-ticks in giardiasis cases in given areas at certain times. Only about 1% of giardiasis cases are reported to the CDC so it’s hard to pinpoint.

Outside of a major outbreak it is usually extremely difficult to pinpoint the source of the infection.

Contrary to what is often quoted, studies have NOT proven hygiene is a greater source of giardiasis in the backcountry (vs water.) There has been speculation in that regard, but it is only speculation. There have been many studies showing a correlation between untreated backcountry water and giardiasis. See the quotes in bold near the top of this page. I have never seen a study similar to the above linking poor backcountry hygiene to giardiasis.

It’s a false choice anyway. NOLS, who likely has more REAL WORLD DATA than anyone. From Wikipedia “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.[35] 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 that lasted an average of 2 days. The occurrence of diarrhea was positively associated with the duration of exposure in the wilderness. A number of behaviors each individually reduced the incidence of diarrhea: treating water; routinely washing hands with soap and water after urination (as did after defecation); cleaning cooking utensils with soap and warm water; and taking multi-vitamins”

Tinidazole is hard to beat for treating giardiasis. It is usually given in one dose and has been shown to be very effective. (consult your physician.)

The minimum infectious dose is not 10 cysts as is commonly quoted. There’s approximately 2% chance of infection with a single cyst.

Chlorine Dioxide (including Aqua Mira drops) works well on giardia if used properly (proper concentration and wait time for the water temp and clarity.)

It is absolutely false that backcountry water is safer than San Francisco city water. That city water is treated with UV light, chlorine and chloramine. Each of those treatments, properly employed, will kill at least 99.9% of giardia cysts.

Actual data shows that preschoolers are in a high giardiasis risk group from poor hygiene in day care centers, while backpackers are in a high risk group if they drink untreated water. Source: CDC.

Again, hygiene vs. water treatment is a false choice as NOLS has clearly shown.

…

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…

"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.–

"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?

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

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.

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!!

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….:)

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.

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.

> 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

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.

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.

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

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