POP QUIZ

You can pick your friend, or you can pick your nose, but you can't pick your friend's nose!

–B.G.–

"Infected with a giardia cyst up the nose? Odd."

That would depend on where the finger was before it was inserted into the nostril, I should think. ;0)

"There was a huge article (also posted here) about giardia a few years back."

Not sure there was an article here, but there have been a few long and detailed threads, perhaps that's what you're thinking of. One linked to an article elsewhere (http://erikschlimmer.com/pdf/GiardiaMyth-Buster.pdf), but that's not available any more (or at least at the moment).

Threads:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=68224

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=68912

Seems like most answers were right on to me. The only "really correct" answer is in a huge article that can't be found; quite the poop quiz.

> That would depend on where the finger was before it was inserted into the
> nostril, I should think. ;0)
Amusing, but not obvious.

What gets transferred to a human is a giardia cyst. This is analogous to a small round egg. It has to reach the intestines, via the stomach, before the cyst can hatch into an active bug.

Exactly how a 20 micron cyst gets from the nose to the stomach and beyond is not obvious at all. Even if it was … snorted?, it would end up in the lungs, not the stomach. From there it would be exhaled.

There is also the question of how often you pick your nose while walking, as opposed to drinking contaminated water or eating food with contaminated hands.

I want to see validated medical research before I believe. (This statement should be read exactly as it stands. Extrapolations are not valid.)

Cheers

"Exactly how a 20 micron cyst gets from the nose"

I don't know about the giardia cysts in Australia, but I believe in North America the minimum size is thought to be 1 or 2 microns. The full adult giardia can be 50 microns or so, but it is the hard little cysts that cause the problems.

–B.G.–

You can pick your nose and you can pick your friends, but you cant wipe your friends on the couch.

Giardia ain't called "beaver fever" for nuttin'.

This month I was hunting in northern Nevada's Ruby Mountains. The ONLY water available was from the south Fork of the Lamiolle Creek which was full of very active beaver dams.

Yes, gentle readers, beavers have been known to poop in the water and they don't wipe either.

I boiled all cooking water and treated drinking water with chlorine dioxide tablets.

I was very careful to use hand sanitizer after getting water from the stream.

Nevertheless upon returning home I took a stool sample to my clinic's lab for a gieardia test. Thankfully it was negative.

P.S. I always, but always use hand sanitizer liberally after pooping. When cooking for others I make it plain to onlookers that I am using hand sanitizer before cooking.

A lot of trail food consumption does not involve utensils.
Stuff like GORP, chocolate ,dried fruit is hand to mouth food.
So to me the ones that possibly contaminate themselves by picking their noses are much more likely to contaminate themselves eating.
The argument that most know not to put dirty hands in their mouth does not hold because most also would know not to shove a brown finger up their nostrils.
To elaborate, if you are not aware that your fingers have been contaminated by others when picking your nose you would not also be aware of that when you eat (munch as you go not necessaraly at meal time…)

> in North America the minimum size is thought to be 1 or 2 microns.
Reference?

"Giardia cysts are typically ovoid, and measure from 10 to 15 µm in length, and from 7 to 10 µm in width"
US EPA

I am willing to believe they could be a littlle smaller, but not by much.

Cheers

I don't know what they are currently teaching in wilderness first aid classes, but about thirty years ago they were teaching that in order to be safe, we needed to filter one order of magnitude smaller than the typical size, because there is a spectrum of sizes. I understand _typical_, but I wouldn't want one of those skinny ones to get by.

–B.G.–

I suspect far fewer people are actually infected in the back-country than they think.

Since the symptoms of a giardia infection don't show up for anywhere up to 3 weeks, how do you really know if you got it from back-country sources? If your trip is a month long then you could be pretty certain but other than that, I'd bet it was from the fast food joint you went to on the way out of town!

Hi Bob

Not arguing.

Cheers

Since the symptoms of a giardia infection don't show up for anywhere up to 3 weeks, how do you really know if you got it from back-country sources?

Even Welch, perhaps the most quoted skeptic, has conceded Published reports of confirmed giardiasis among outdoor recreationists clearly demonstrate a high incidence among this population.

The source of infection can be difficult to determine with absolute certainty with individual cases. Many thru-hikers report giardiasis though, and in the big picture the CDC has data showing backpackers drinking untreated water are in a high risk group for giardiasis, while "fast-food eaters" are not in a recognized high risk group for giardia.

The CDC has used their huge data base to come up with the following:
Anyone may become infected with Giardia. However, those at greatest risk are

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

There's a reason physicians often ask "Have you been camping? Did you drink any untreated water?"

The answers lie in verifiable data.

Let''s take it as fact that Giardia can pass through the nose to infect. Further, it is known that drinking untreated water can cause the sickness as can food contamination from others. Add these and other potential causes like swimming in contaminated water, washing your face with contaminated water and there are now a multitude of potential causes. Often threads focus on water treatment and giardia but all these other factors are what skews the data.

But here's the good news…….. As a solo hiker, many of the potential human related causes to away.

"Not arguing."

Roger, I think you are just trying to be self-moderating.

–B.G.–

>> Published reports of confirmed giardiasis among outdoor recreationists clearly demonstrate a high incidence among this population <<

I think this statement just confirms my point, that what is reported by an infected person is often not correct and only serves to skew the data. Just because you have giardiasis and were in the back country doesn't me you got it from a wild water source but that's the first question your doctor will ask you (were you drinking from untreated water sources in the back country). There is no way of knowing if the wild water was the source of the infection or if the suspect water was effectively treated by the hiker.

From a lengthy Ontario (Canada) study:

"The most frequently reported probable risk settings were the home (40.1%) and travel (39.1%). The study findings suggest that a high proportion of cases occur in urban areas…"

The highest infection group is children, who have double the rate of infection as adults, and they are not being infected by drinking wild water in the back-country.

Have you noticed that some people will religiously filter or treat water?

But then same people dont give a second thought to rinsing socks or clothing out, soaking feet, taking sponge bath, rinsing hands, face, swimming, etc.

Any contact with contaminated water could be a way for cysts to find its way onto your hands, and into your mouth.

But still, it seems more anecdotally common I think for those that dont treat water, to get sick than for those that do.

Bob,
Aussie :not arguing
New American : this

"this" happens to be my pet hate right now…

>>Everyone has some stran of giardia in them. You are just immuned to "your" stran"

I might have missed it, but no one has corrected this bit of misinformation. Everyone does NOT have giardia. Mayo Clinic: "Some people with giardia infection never develop signs or symptoms but still carry the parasite and can spread it to others through their stool." Maybe you are thinking of this? Certainly, this isn't the majority of people.

Also, you don't give yourself giardia (auto inoculation), as seemed to be implied earlier in the thread.

Strain not stran

"Also, you don't give yourself giardia (auto inoculation), as seemed to be implied earlier in the thread."
I might have inadvertently done that.
My comments were about sharing rather than self administration.

I'm missing something here…

Is there a suggestion that one can have non-symptomatic giardia in the gut, and through less-than-ideal hygiene habits, introduce giardia orally, and then become symptomatic?

Hi Bob

> "Not arguing."
> Roger, I think you are just trying to be self-moderating.
No, I was agreeing with you!

Cheers

Hi Greg

> Is there a suggestion that one can have non-symptomatic giardia in the gut,
Yes, it happens. A sort of balance is reached with limited harm.

>through less-than-ideal hygiene habits, introduce giardia orally, and then become symptomatic?
Very doubtful, imho.
Giardia is an 'infection' of the intestines. The cysts are excreted. If you reintroduce the cysts from your intestines back into your intestines, there is no reason for you to become suddenly susceptible.

Cheers