"The interesting thing is that both are classified as antibiotics because they are used to treat certain bacterial infections as well as for parasites."

It is also used to treat "Hole in the Head" disease in fish. Would it work for humans??????

"That is interesting, because antibiotics generally treat bacterial infections. If you want to treat Giardia, you need to use an anti-parasite drug such as Flagyl."

Antibiotic is a general pharmaceutical term that include antibacterial, antiviral, anti-parasitic and anti-fungal medications. In lay terms it has become most associated with antibacterials. Metronidazole (Flagyl) has uses for against both certain bacteria and certain parasties, as previously mentioned.

Cure rates for Giardia are currently listed at ~80% with antibiotics. Even without treatment many people improve on their own, though a typical course of giardia is 3-5 weeks. Fun...

Edited by BER on 04/24/2012 08:34:59 MDT.

If Giardiasis is so unlikely but at the same time the most meticulous water treatment seems to be no guarantee it seems a logical conclusion would be that treating is pointless. It would seem the defining factor is the presence of the stuff, not what we do to the water.

I mean, honestly, if treatment didn't work I can't see how the conclusion can be "always treat your water". Sounds quite bold. It seems clear there are other factors at play and we don't know which they are.

Sorry for your illness.

Can you elaborate on the timing of your exposure to the suspect water and the onset of symptoms?

I saw something on another site referring to bleach not being effective against Giardia cysts, though chlorine dioxide treatments are. So perhaps it is your washup technique that got you infected with some cysts.

My sympathies - I contracted Giardia in Nepal long ago (most likely from food though I did once accidentally moisten my toothbrush from tap water) and did feel like I wanted to die at times. I kept thinking it was something else (altitude nausea) but finally took the 1-time dose of tinidazole (what they dispense there for it) and started feeling better within 24 hours. My partner, after 2 trips in Nepal each with a Giardia affliction, as well as a U.S. contracted case, is now dubiously blessed with the ability to diagnose by the smell of the farts (he once told a co-worker to go get stool tested, and turned out to have correctly identified Giardia).

Needless to say, we both treat our water.

Mitchell,

Sorry to hear about your bad experience.

Would you mind detailing how long you waited to drink the water after putting the chlorine dioxide pills in and an estimate of how cold and cloudy the water was?

To those who are not doctors on this thread: Flagyl IS an antibotic. It's generic name is metronidazole and it is used to treat anaerobic bacterial infections, ameobic and protozoan parasites of which giardia is one. The course my doc prescribed is a 7 day course 12 hours apart for each dose taken with food. It has not left me feeling worse than dead.(In fact I have felt just fine taking it.) I take massive doses of acidolphilus to counteract the effects on the flora in my intestinal tract. I have been told by him that in mild cases, which mine appears to be (since I appear to have had a period of time in which I felt fine and was symptom free,)that I can look to a complete recovery and no relapses in the future. I guess time will tell.

And I have heard that it can be contracted by the simple act of washing my face and getting it into my eyes or nose. Remember, it only takes a couple of cysts to contract the infection.

So a word to the wise: treat your water as I have done and if washing in stream water treat it, too. In fact treat all water you encounter including so called "safe" potable water from the taps in campgrounds and at trailheads such as one finds in the Sierras.

And finally, I did start this thread to find out if anyone has seen an uptick in the incidence of giardia in their area as I have and as confirmed by vets I have spoken to in Orange county, Riverside county and Marin county.

And to answer those who wish to know how I treat my water and how long it took to get the symptoms after exposure.

I use the chlorine dioxine pills and have done so since they came out about 5+ years ago. I use one pill per liter and usually wait 15 minutes to 20 minutes before drinking. I also drop a elixir electrolyte tab in at the same time. If the water is really cold, i wait 30 minuutes. I rarely find the water I use to be cloudy or silty.
I will be using the pills from now on in my wash basin and in the water I use to wash my face in.

By my best estimate I contracted the infection about 7 days before I showed any symptoms. I have been told by the doc that I could carry it for anywhere from 24 hours to a month before showing symptoms. It often depends on the vector load one ingests and/or one's natural level of resistence or general health.

Edited by mkeil on 04/24/2012 11:07:02 MDT.

This thread seems to be fear mongering over a case of Giardia that is not proven to be from the backcountry.

I must need to start filtering my water at work and home, too. No reason to frighten people about "potable" water.

John: "This thread seems to be fear mongering over a case of Giardia that is not proven to be from the backcountry"


Without a RECENT water sample from every single source drank from on any given trip, how could anyone ever prove that giardia was obtained from the backcountry? I doubt most cases are ever proven in such manner but rather treated empirically based on symptoms & suspicion initially and possibly confirmed with stool specimens after the fact. When you describe the symptoms to a doctor, they will inevitably ask you if you have travelled to a foreign country, drank water from a potentially suspicious source, etc. If you tell them that you just returned from a backpacking trip a week ago (incubation period ~ 1-2 weeks usually) and drank from streams, unless there has been a surge of other patients in the area presenting with similar symptoms that would be a clue that the municipal supply is contaminated (ex: 1993 Cryptosporidum outbreak), the doc will suspect that the backcountry water is the culprit. But proof? None whatsoever. So I don't think it's really fear mongering to assume that the source was the backcountry water, when it seems to be the most likely cause, especially since the time to symptom onset falls into the typical incubation period. Just my thinking anyway. :)

"I use one pill per liter and usually wait 15 minutes to 20 minutes before drinking. I also drop a elixir electrolyte tab in at the same time. If the water is really cold, i wait 30 minuutes."

What temperature was the water? It's quite possible that your wait time for protozoan cysts such as giardia may not be sufficient. Here's a table from the EPA for chlorine dioxide tablets:
http://www.equipped.com/graphics/MP1ChartB299H141.gif
Here's the gist of the table (also found in many other places, such as the Katadyn website and Wilderness First Aid texts):

Cysts Clear water, 20*C [68*F]: 30 minutes // Turbid water, 4*C [39*F]: 4 hours

It would be nice if the EPA would furnish a few intermediate numbers for estimating contact time for conditions between the two! For those of us who backpack in the high mountains, water from springs is likely to be in the 30s F but is usually clear. It's obvious that the 4 hour wait time on the package is the absolute worst case scenario. I once asked Katadyn if they had any intermediate numbers, and they said no, implying, although not actually saying, that the EPA wouldn't let them release such numbers anyway. This leaves us all up a creek (bad pun, I know) on contact time, unless we want always to assume that worst scenario!

Anyway, it is possible that your stream water was cold enough to require a longer contact time, since it was probably colder than 68*F.

It's also possible that the electrolyte tablet might reduce the effectiveness of the chlorine dioxide tablet because it in effect increases the turbidity of the water. You might consider waiting to add the electrolyte tablet until the chlorine dioxide tablet has been in the water for the appropriate treatment time (whatever that is, but probably longer than your 20-30 minutes). I'm inferring (i.e. slightly educated guess) on this one, though.

Without sampling your water source specifically for giardia (normal water tests are for coliform bacteria), specifically at the time you ingested it, we'll never know for sure!

As for the dog outbreaks--we'll probably never know, either. However, if you've ever watched two dogs greet each other, you can easily guess one possible contamination source! In my dog's case, the backcountry exposure was either 4 weeks or 3-4 days before the symptoms, neither of which fits the incubation period. However, he was at the beach, where he has a habit of lapping ocean water, about 10 days prior to symptoms. He also got acquainted with quite a few dogs during that period. Again, we'll never know for sure.

I do assume that my backcountry water sources may be contaminated, so I filter (heavier but faster and better tasting). You never know what's upstream--I've found both live and dead animals, several different times. Even if only 20% of my sources (generally lakes and streams rather than springs) are contaminated, that's more than I want to risk.

Maybe a dog with giardiasis was in the water upstream of where you got your water?? Now that's really in the realm of pure speculation!

Edited by hikinggranny on 04/24/2012 13:53:21 MDT.

yes in OC - HB, because of the rain, water puddles up around the construction sites, as well as the Bolsa Chica wetlands (formerly known as swamp) - a popular mosquito and viral breeding environment.

Been seeing those giant dinosaur mosquitoes fly in the house on occasion.

My dog like many dogs likes to eat a little green grass salad, I suspect he picked up an intestinal viral parasite from the larvae that mosquitoes lay on the dewy grass.

According to the Myth Busters show, supposedly dog's saliva has some antiseptic in it, but it's not a 100% cure all. We give the dog the regular pet meds for fleas, and HeartGuard for worms.

Just camped at Devore myself. I always treat that water (UV) because it's not exactly the Sierra and lots of joggers/day hikers (with pets)go through especially on weekends. With that kind of human exposure I would not be surprised if the stream is contaminated. I still don't treat water much in isolated places.

I always assume that a mouse, bird, squirrel or deer drank from it and defecated within 2 ft of the water.

if you look carefully, those aren't raisins or chocolate chips. Rain mixes clean with contaminated water.

I've even found snow on the side of the trail to be contaminated.

Hi Randy. My comment was a bit too general..yes. Some of what I saw Mary D has commented on, there seeming to be holes in Mitchell's treatment technique (only 15 minute waits, adding other tablets at the same time as treatment tablets). The other thing is that he said nobody should drink from campsite potable water spigots without treating? Now that seems a bit over the top from a single case of "possible" giardia from the water source he is suspicious of. Sorry for being too general or otherwise inflammatory ; ).

I've never heard, nor can easily find, info on transmission of Giardia through the eyeball. Get an article reference if possible. Getting water in nose (then swallowed) or mouth could certainly get one sick. The CDC website says it can take as little as 10 cysts.

Edited by jshann on 04/24/2012 19:58:08 MDT.

Mitchell, according to your advise we wouldn't be able to swim in the lakes/rivers, neither probably raft, canoe or kayak. In all honesty, nature doesn't work that way. I know this is a tricky issue with few real info and lots of noise but I'd advise you to do some honest research on the real dangers so you can take useful actions and not only placebos. And please don't add up to the noise, there's already enough of it.

You know one of the reason I left BPL was that the posters get entirely too focused on their own agendas and opinions. That has resurfaced with this thread.

I did have Giardia despite the posts that seem to question that (My course of treatment is finally over today). Really, you are a doctor and examined me to know that I didn't?

My comment about potable sources is certainly a real possibility and only applies to the spigots that we see at TH. Do you really know if it has not been compromised? Haven't you noticed the conditions of the ground around these spigots. Who knows what someone may have left on the spigot itself when they washed their dishes there or cleaned fish there (despite that you are not supposed to). I know they are supposed to be tested but does anyone know how often? And does anyone care to bet on the piping integrity after a winter? And does anyone care to guess how the federal and state budget cuts are affecting the ability of the forest service to monitor these sources?

Although I can't be 100% certain that I got giardia from the particular stream I camped by, I can be almost certain since I did not use any other water than from this source and had not been out for more than a month prior to this hike and had not treated any water to drink in more than 2 months (using only water from home for hikes). That pretty much limits my exposure vector don't you think?

Perhaps I could increase the time to drink after dropping a pill into the container and perhaps it does compromise effectiveness by also dropping in a hydration tab. But I have been doing this for 5 years without a problem. And I have seen nothing in the literature that would indicate that the hydration tabs which do not cloud the water have any adverse effect. If time to effectiveness is a problem then perhaps I should switch to a SteriPen approach. Waiting more than 30 minutes for the pills to work is a bit more than I want to wait, and if it is even longer for cold water, what's the point of using them? How religiously do any of you who use the pills wait the full 30 minutes or much longer for cold water? Let's get real on this.

Since it takes so few cysts to create a real health problem why not err on the conservative side and treat all water you drink? If you swim, raft, kyak or tube in wilderness water, what risks do you run? I don't know. How you limit your exposure to water borne vectors is your business and perhaps it is just a risk one runs to enjoy the natural wonders of our country. But it is a risk however quantified.

My initial question has only been addressed by a very few posters. I wonder why.

http://www.sierranaturenotes.com/naturenotes/Giardia.htm

An interesting quote: "Recall that San Francisco water can contain a concentration of 0.12 cysts per liter,24 a figure now seen to be higher than that measured anywhere in the Sierra. San Francisco city officials go to great lengths to assure their citizens that the water is safe to drink, and if true—as it most assuredly must be—this comparison alone is quite revealing."


To the OP, you were the one that started with your own "agendas and opinions." Based on scientific data, there is no need for you to push this obsessive fear of (even potable) water. Offer up your experience, share what happened to you, but don't get upset when others defend how safe backcountry water typically is when caution is exercised. There are many more (likely) possibilities than you alluded to.

Mitchell, I don't know or care how your were infected, but I do care that you did get infected.
What a literal pain in the butt!
Thanks for sharing.

Tad

Yeah, thanks for the info Mitchel

Even though there's no clear scientific answer. Very confusing that you tested positive for Giardia yet treated all your water.