Why the Rockwell Giardia Article should be removed from Whiteblaze

[Colter]

Firstly, let me say that water treatment is a personal choice regardless of the validity of the Rockwell article.

Secondly, accurate information is vital to make a reasonable risk assessment. Unfortunately, most of the key points Rockwell makes are critically flawed. They do not represent mainstream science, good science, or even good critical thinking.

Thirdly, discussion should be encouraged. The article as posted on Whiteblaze allows no comments which is especially bad because it presents misleading medical advice without giving readers a chance to respond.

The Whiteblaze intro to the article says Until someone publishes a study about the Appalachians in particular, there is not much data out there at this time about overall water quality along its length.

There has been a very good study on A.T. hikers: Medical Risks of Wilderness Hiking It says in part 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. ...Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water... It found, by following the actual results of treating/not treating of water on the A.T., that those that treated water were significantly healthier as a group. To me it makes no sense to post a poorly researched, inaccurate, non peer-reviewed paper focusing on the Sierra, when there is a well-researched, peer-reviewed scientific paper focusing on the Appalachian Trail.

Rockwell quotes TR Welch who said Neither health department surveillance nor the medical literature supports the widely held perception that giardiasis is a significant risk to backpackers in the United States That is absolutely false. The CDC specifically refutes TR Welch's writing Although the advice to universally filter and disinfect backcountry drinking water to prevent disease has been debated, the health consequences of ignoring that standard water treatment advice have been documented Multiple, peer-reviewed papers have shown a link between giardiasis and not treating backcountry water. Welch and Rockwell are the source of the lion's share of giardia misinformation.

I could continue but will keep it simple for now. I have written more with many links to scientific studies on giardia and water treatment for backpackers.
Why Rockwell's Giardia Paper is Bad Science
Debunking a TR Welch Giardia Paper
Waterborne Giardia for Backpackers: No Myth

[Don H]

So can we get a link to the Rockwell paper?

[Colter]

So can we get a link to the Rockwell paper?

It's in the first sentence of my post. "Rockwell article" is clickable.

[Malto]

This article appears to be very consistent with other research that I have seen for THE SIERRA. As such it must be taken in that context. I would agree with Colter that other studies should be included in the thread and as always the readers can make up their mind.

there was one line in the article that is worth noting. Often there are discussion about how to know whether you in fact have giardia. This is how, at least in my experience.

"The type of diarrhea can help in the diagnosis: If it is liquid and mixes readily with water rather than floating on top and is not particularly foul smelling, the problem is likely something other than giardiasis. Diarrhea which lasts less than a week, untreated, is probably not from giardiasis."

[Colter]

This article appears to be very consistent with other research that I have seen for THE SIERRA..."

If you provide citations, they will likely be from Derlet who has found many water sources testing pathogen free, and many others containing human pathogens, which in my opinion doesn't align with Rockwell's "Drink freely and confidently" statement. Rockwell's paper is full of bad information even taken in the context of it's focus on the Sierra.

Derlet is not going to agree with the Rockwell article as written. According to REI, Derlet says he would likely treat all water he would gather along the Appalachian Trail

I don't think there is one professional epidemiologist in this country that would agree with Rockwell's statement you can indeed contract giardiasis on visits to the Sierra Nevada, but it won’t be from the water. So drink freely and confidently It's a foolish blanket statement in a purportedly scientific "paper." It's part of his summary, and if his summary is untrue, the essence of his paper is untrue. If I'm not mistaken, Malto, you and I have both gotten giardia from Sierra Nevada water. Doesn't align with Rockwell's claims in my mind.

It's the exceptions that make people sick, and water testing has proven the exceptions are common, including in the Sierra.

I don't think it's reasonable to ask people to make up their own mind based on bad information they've been provided.

[Malto]

Yes I did get giardia from Sierra water but it was near Sonora pass that had cattle grazing which is a primary place where Derlet found the fouled water. You are right that you really have to qualify the Sierra statement to the high Sierra inside the protected wilderness areas.

[rickb]

What article? I found the abstract, but that hardly illuminates:

The risk of diarrhea was greater among those who frequently drank untreated water from streams or ponds (odds ratio [OR] = 7.7; 95% confidence interval [CI]: 2.7 to 23; P <0.0001), whereas practicing "good hygiene" (defined as routine cleaning of cooking utensils and cleaning hands after bowel movements) was associated with a decreased risk (OR = 0

[Colter]

What article? I found the abstract, but that hardly illuminates:

The risk of diarrhea was greater among those who frequently drank untreated water from streams or ponds (odds ratio [OR] = 7.7; 95% confidence interval [CI]: 2.7 to 23; P <0.0001), whereas practicing "good hygiene" (defined as routine cleaning of cooking utensils and cleaning hands after bowel movements) was associated with a decreased risk (OR = 0

Only the abstract of Medical risks of wilderness hiking is available for free as far as I know, and I think it does illuminate by summarizing the results: this large group of Appalachian Trail hikers was healthier when they avoided untreated water and practiced good hygiene.

[rickb]

Looks like only 21% of the men in the study treated water consitantly-- and about 56% of all hikers had diarrhea sometime during their hikes.

It might have been a "very good study" but the only conclusion I would draw without seeing it in its entirety is that very few AT thru hikers treat their water consistantly.

[oleary92]

Thanks OP for posting this. I had giardia for 6 months and it was *****ty*

[Colter]

...the only conclusion I would draw without seeing it in its entirety is that very few AT thru hikers treat their water consistantly.

Is there some reason you would believe their stats about the percentage of people consistently treating water (in 1997) but not their stats on drinking untreated water and the incidence of diarrhea?

[Wise Old Owl]

Of course this is very dry reading.. and I have a theory that after multiple incidents of getting the virus the body adapts and deals with it.. hense my bet is once you have been sick several times... it doesn't matter ... Once it is posted - perhaps it should stay, regardless of this issue, People need to treat their water.


Hey look at this a different way. The science about DDT was flawed and is still being studied... it was a political decision of the time..since then millions of african babies have died since the change in law here in America, very sad and true.. the fight goes on.

[rickb]

Is there some reason you would believe their stats about the percentage of people consistently treating water (in 1997) but not their stats on drinking untreated water and the incidence of diarrhea?

I am not sure I understand your question.

You had mentioned that there is a "very good" (your characterization) "Medical Risks of Wilderness Hiking" study out regarding the benefits of treating water on the AT, and posted a link to the abstract. I found that interesting then pulled up the Abstract and expressed an interest in actually reading that study, but apparently it is not available on line-- at least not free of charge.

I did Google up a summary of some of the data from "Medical Risks of Wilderness Hiking" study, however. That's where the stats I posted came from. From what I saw, only 21% of the men in the study and 31% of the women treated their water consistantly. Could one still draw valuable conclusions form such a population? Sure. I would very much like to see the author's regression.

One thing of note is that this sudy makes no mention of Giardia-- only diarrhea. I can understand that-- you don't get a diagnosis by survey. On the other hand, then length of times reported for having diarrhea were very short-- an the standard deviation as measure in days was too. I'm not sure what that means.

To be clear, I am not challenging this AT study you referenced-- like you I have only read the abstract and the summary data from this AT study I posted in my prior post.

[Chair-man]

Personal Hygiene is more important on the trail than at home.
Think about this. How many cat holes do you think are around the tent site your camping in? Now you set up your tent over the cat hole mind field. Ever look at your hands after you pull up those dirty tent stakes? If your one of those hikers who don't carry hand sanitizer, wipes or soap because it weighs too much, you might want to rethink it.

[Starchild]

Thank you Colter for posting this which now allows user comments, though in a backwards way, and this thread shows why they are so needed. It allows interaction, and sometimes exchange of vital information that is lacking and also provides a way to legitimately challenge the information posted.

I do agree that it should be removed from a status that no one can post comments, this seemingly should not stand on it's own or at least there are potential issues about it that should to be open to discussion.

All IMHO

Peace

[Colter]

Fair enough, Rickb. I guess I was saying there's enough info in the abstract to draw reasonable conclusions, and you are saying it would be even better to read the whole thing, and I agree.

Chair-man, I'm not sure hygiene is more important on the trail, but there's good evidence that it IS important. FWIW Giardia is a problem even in wilderness areas of Alaska: http://forums.outdoorsdirectory.com/...ver-Fever-quot

I'm a big fan of looking at actual results vs. theory. 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.[34] 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 (Wikipedia)

''The pristine character of the wilderness environment often lures students into a sense of false confidence, believing that sound hygiene is unnecessary and that all water is safe to drink..."
NOLS Wilderness Education Handbook.

Regardless, I didn't want to this to be another debate about water treatment, but whether the facts Rockwell presents are reasonably accurate. In my opinion it's clear they're not, and if they're not I don't think it's appropriate that bad medical advice be posted in the Articles section.

[HikerMom58]

This is most civil discussion I have ever witnessed on WB. WTG!! :>) Interesting & very informative.. Thanks Colter!

[Nutbrown]

Personal Hygiene is more important on the trail than at home.
Think about this. How many cat holes do you think are around the tent site your camping in? Now you set up your tent over the cat hole mind field. Ever look at your hands after you pull up those dirty tent stakes? If your one of those hikers who don't carry hand sanitizer, wipes or soap because it weighs too much, you might want to rethink it.

wow, I had never though of tenting with this in mind.... I do always have hand sanitizer, and wet wipes though. Now I won't waver when weighing things...

[rickb]

While I couldn't find the AT study that suggests consistant water treatment on the AT is the responsible course of action, I found a similar one from the same author on a related topic. What's more, it draws from thesame data set (hiker survey).

It is worth reading, but in the end I found it not nearly as informative as it could have been, IMO.

The author observes that about 1/2 his respondents got diarrhea and 1/2 didn't-- whether or not they treated water on a consistant basis. He further reports that only about 21 percent of the men and 31 percent of the woman respondents treated their water consistantly.

His numbers did show that the regular treaters did get diarreah about 20% less oftern, and so did those who practiced better hygiene. That is instructive, but left me wanting more.

The study made no attempt to do a regression with multiple variables. To my way of thinking, those who filter more regularly might be much more likely to practice better hygiene. Like the women treat their water consistantly at a rate 50% greater than men according to the survey. Correlation does not equal causation.

That doesn't mean the author's conslusions were wrong by any stretch-- it just that this one study may not have been all that rigorous in my opinion. Here it is the link -- but remeber, it's not the same one that Coulter referred to at thebegi ningof this thread. Itjustdraws from the same data on a related topic by the same author.

http://onlinelibrary.wiley.com/doi/1...2004.13621/pdf

[Colter]

rickb, you seem like an educated man showing some critical thinking. Do you have any comments on the Rockwell giardia paper, specifically on the key points I addressed here?

If my thinking is in error, people should feel free to explain why. If my critique is valid, Rockwell's paper should not be presented as science. It matters, and not just as who wins the debate but as a matter of trail health in the real world.