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#119943 - 08/26/09 10:17 PM leptospirosis filter
mantashrimpman Offline
newbie

Registered: 08/26/09
Posts: 4
Loc: honolulu
is there any backpacking water filter that will filter out leptospirosis?

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#119944 - 08/26/09 10:39 PM Re: leptospirosis filter [Re: mantashrimpman]
lori Offline
member

Registered: 01/22/08
Posts: 2801
All of the filters will remove bacteria. If you are looking for the most thorough filter, the First Need purifier would be "it" - it also filters viruses. Not even a bacterium smaller than .2 microns would slip through.

It appears that it's most often a danger when you're swimming in the water. So filter and don't swim.
_________________________
"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki

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#119949 - 08/27/09 02:59 AM Re: leptospirosis filter [Re: lori]
Pika Offline
member

Registered: 12/08/05
Posts: 1726
Loc: Rural Southeast Arizona
I'm not sure that even the First Need will "filter" viruses; most of them are smaller than 0.2 microns (200 nanometers). Viruses are generally less than 100 nanometers in diameter. For example, the equine encephalitis virus is about 60 nanometers in diameter while the bacteriophage viruses Ψ174 and PRD1 are 23 and 63 nanometers in diameter respectively. From what I have been able to find, Leptospirosis is less than 25 nanometers in diameter. Perhaps the first need has some sort of iodine bed treatment for viruses in addition to its filter.

A micron is 1/1,000,000 of a meter, a nanometer is 1/1,000,000,000 of a meter.

The best thing to use against virus is something like ClO2 (Micropur) or UV light (Steripen). Personally, I would not trust claims about filtering viruses.
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#119950 - 08/27/09 05:46 AM Re: leptospirosis filter [Re: Pika]
leadfoot Offline
member

Registered: 07/16/03
Posts: 954
Loc: Virginia
Leptospirosis is a bacteria. It is found in rodents, dogs and also humans. You can call the manufacturer of whatever filter you have/want and see if it covers this type of bug.

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#119951 - 08/27/09 08:25 AM Re: leptospirosis filter [Re: mantashrimpman]
Dryer Offline
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Registered: 12/05/02
Posts: 3569
Loc: Texas
I use bleach to kill anything the filter didn't get, if I filter at all. Any of the chemical water treatments should do the trick. Bleach is cheap and is what my muni water department uses.
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#119955 - 08/27/09 09:22 AM Re: leptospirosis filter [Re: Dryer]
lori Offline
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Registered: 01/22/08
Posts: 2801
Bleach doesn't do much for crypto or giardia, per the CDC. Bleach in amounts that would be effective against cysts would make the water undrinkable.
_________________________
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#119956 - 08/27/09 09:28 AM Re: leptospirosis filter [Re: Pika]
lori Offline
member

Registered: 01/22/08
Posts: 2801
Originally Posted By Pika
I'm not sure that even the First Need will "filter" viruses;]


"The First Need Deluxe Water purifier has a 0.1 micron carbon matrix filter element which cranks out a rapid 1.8 liters per minute. "

test data

It's the main selling point of the purifier.
_________________________
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#119960 - 08/27/09 09:59 AM Re: leptospirosis filter [Re: leadfoot]
Pika Offline
member

Registered: 12/08/05
Posts: 1726
Loc: Rural Southeast Arizona
Quote:
Leptospirosis is a bacteria. It is found in rodents, dogs and also humans.

Yeah, I didn't mention that did I? Still, the data I found indicate that it is small, around 25 micrometers in diameter.

If I suspect that there is virus contamination of the water I am using, I will treat with a chlorine source after filtering to remove potential Giardia or Cryptosporidium cysts.

When I was working in Morocco a while back, a colleague got hepatitis from drinking filtered, non-chlorinated water. I don't want to go through what he did so I double treat if at all in doubt.

Just generally, I tend to be a bit skeptical of a lot of filter claims. I mean, they are not the ones who suffer if their product is, for some reason, slightly below specifications, are they?


Edited by Pika (08/27/09 09:59 AM)
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#119966 - 08/27/09 10:26 AM Re: leptospirosis filter [Re: Pika]
lori Offline
member

Registered: 01/22/08
Posts: 2801
Originally Posted By Pika


Just generally, I tend to be a bit skeptical of a lot of filter claims. I mean, they are not the ones who suffer if their product is, for some reason, slightly below specifications, are they?


I think about this a lot too. But I also think about the real vs imagined prevalence of "stuff" in the water and the folks I've hiked with who just dip water out and drink who are still out hiking and not sitting on the throne at home suffering for it.

Selection of water source and being prepared if the only thing available is a tepid, low flow spring that's being collected in a moss filled trough is about it. I have added Micropur tabs to filtered water before, I'll probably add boiling to that if I'm really skeeved by the look of the source. Something to be said for educating yourself on water sources prior to the trip.
_________________________
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#119967 - 08/27/09 10:39 AM Re: leptospirosis filter [Re: Pika]
OregonMouse Online   content
member

Registered: 02/03/06
Posts: 6372
Loc: Gateway to Columbia Gorge
Actually, most municipal water departments use chlorine dioxide, not sodium hypochlorite (chlorine bleach), which, I've been told, can leave some nasty compounds behind it.

My-daughter-the-veterinarian told me that to prevent leptospirosis, I should keep my dog out of stagnant ponds or small lakes that have no outlet, especially when cattle are present, and treat his water from such sources. This is a good rule for humans, too! There is a canine vaccine for leptospirosis, but it often causes severe reactions and, per the University of California at Davis School of Veterinary Medicine is not very effective. My dog is actually owned by Canine Companions for Independence, even though he was rejected as an assistance dog, and they do not allow their dogs to get the lepto vaccine.

I would assume that the same rules apply to humans. If you're in cattle country, take along some chlorine dioxide tablets (I take some anyway in case something happens to my filter), and resist swimming in lakes with no outlet. The filter will take care of the protozoa that chemical treatment takes 4 hours to zap, so you only need 20-30 minutes' chemical treatment to kill bacteria and viruses.

I did a little googling but couldn't find out if lepto bacteria are of a size that most filters will remove. Thanks for finding this out!
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#119976 - 08/27/09 11:59 AM Re: leptospirosis filter [Re: Pika]
leadfoot Offline
member

Registered: 07/16/03
Posts: 954
Loc: Virginia
I agree with ya, Pika. smile Some viruses are pretty small and not filterable. I use my Steripen or the tablets, depending on where I am and how much water is available.

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#119977 - 08/27/09 12:18 PM Re: leptospirosis filter [Re: lori]
Pika Offline
member

Registered: 12/08/05
Posts: 1726
Loc: Rural Southeast Arizona
Quote:
Something to be said for educating yourself on water sources prior to the trip.


Right. I think this is one of the benefits of experience; thinking about water sources before the trip. It is almost mandatory here in Arizona. I do a lot of spring, early summer and autumn hiking in desert mountains and cattle country. Mostly there is no flowing water, it is usually found only in water pockets or murky pools. So, I generally and routinely use a filter followed with Micropur tablets. When the water, after filtering, is the color of urine, or tea, one feels the need to do a bit more with it before drinking. I need to clean the filter a lot also; up to two times per liter. Once in the Grand Canyon I took water from a small pool with a dead coyote floating in it: no real alternative. I also carry a lot of water if the need arises.

Sometimes I think a person could gain weight by drinking Arizona mountain water straight, without treatment, if they didn't get sick first. There is probably 100 calories per liter of critterhood swimming in, and just soaking in the sources.

In the summer and early fall, I generally spend 2-3 weeks and 2-3 trips in the Sierra. There, I will use a Steripen or filter when I am mostly in popular (crowded) areas. I like the Steripen but don't trust it entirely. Otherwise, I don't treat the water at all if I have a good idea of what is upstream. On my trips to more remote places, I leave the water treatment machinery at home. If in doubt, I'll drop in a Micropur tablet.

Up until about ten years ago, I never treated my water at all unless it really looked bad. Then I would boil it. I don't recall ever getting sick: well, once when I was in the Army I picked up a case of amoebic dysentery in North Carolina from drinking contaminated water. I suspect that, in over 60 years in the hills, I have developed resistance to some of the more common bugs.


Edited by Pika (08/27/09 12:21 PM)
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#119978 - 08/27/09 12:25 PM Re: leptospirosis filter [Re: Dryer]
Fiddleback Offline
member

Registered: 06/22/04
Posts: 478
Loc: Northern Rockies
Lori is correct. Bleach is not considered effective against crypto and giardia. Nor do municipal systems use it. Older systems use cholrine (in gas form, I think) and as time goes on, municipalities are moving to chlorine dioxide which is effective against the above. A prime reason for the change was the breakouts of giardia from treated municipal water of sytems using the older chorine treatments. The incidence of giardia breakouts has been sigificantly reduced with the chlorine dioxide treatments. Many (most?) of the upgraded systems have also added UV treatment as a final 'dose' for the water.

When it comes to filters the main thing is size. What is the size of the threat and does the filter filter out buggies of that size? Specs from the manufacturers I've looked at give that information.

FB
_________________________
"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution

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#119980 - 08/27/09 12:47 PM Re: leptospirosis filter [Re: OregonMouse]
Rick_D Offline
member

Registered: 01/06/02
Posts: 2801
Loc: NorCal
I'm not sure that's true, at least in the States. I can't name a single California city using it. I believe it fairly common in Europe, but to the best of my knowledge chlorine (either via Cl gas or sodium hypochlorite) and chloramine are the usual chemical treatments here. ClO2 has some issues with transportability and usually must be manufactured on site. It is commonly used in paper manufacturing though.

That's not to say it isn't better than chlorine or chloramine.

Cheers,

Rick

Originally Posted By OregonMouse
Actually, most municipal water departments use chlorine dioxide, not sodium hypochlorite (chlorine bleach), which, I've been told, can leave some nasty compounds behind it.

My-daughter-the-veterinarian told me that to prevent leptospirosis, I should keep my dog out of stagnant ponds or small lakes that have no outlet, especially when cattle are present, and treat his water from such sources. This is a good rule for humans, too! There is a canine vaccine for leptospirosis, but it often causes severe reactions and, per the University of California at Davis School of Veterinary Medicine is not very effective. My dog is actually owned by Canine Companions for Independence, even though he was rejected as an assistance dog, and they do not allow their dogs to get the lepto vaccine.

I would assume that the same rules apply to humans. If you're in cattle country, take along some chlorine dioxide tablets (I take some anyway in case something happens to my filter), and resist swimming in lakes with no outlet. The filter will take care of the protozoa that chemical treatment takes 4 hours to zap, so you only need 20-30 minutes' chemical treatment to kill bacteria and viruses.

I did a little googling but couldn't find out if lepto bacteria are of a size that most filters will remove. Thanks for finding this out!
_________________________
--Rick

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#120005 - 08/27/09 11:12 PM Re: leptospirosis filter [Re: Rick_D]
midnightsun03 Offline
member

Registered: 08/06/03
Posts: 2936
Loc: Alaska
Ok, we're talking about apples and fish here.

Crypto and giardia are protozoa, not bacteria. They are much more resistant to chemical treatment because they are eukaryotes (i.e. complex organisms).

Leptospirosis is a spirochete (bacteria), which are prokaryotes, or simple organisms. Moreover they are gram positive, so they are more easily destroyed by antimicrobial chemicals.

I took a microbiology class this summer, and one of the exeriments we had to do was test the effectiveness of antimicrobial products on a bacteria. I discovered that chlorine bleach was mildly effective against E. coli, but hydrogen peroxide was extremely effective! I don't recall the water treatment product that contains oxygen, but it is one I would certainly lean toward. I didn't get a chance to test iodine (couldn't find it when I needed it!), but found that grapefruit seed extract was more effective than bleach, and lysol kitchen and bathroom cleaner was not effective at all!

In a similar experiment I found that Vietnamese cinnamon was extremely effective against E. coli (this is the real deal stuff that tastes just like a cinnamon red-hot candy, not the old stale flavorless stuff you get at Costco by the pound). I will be adding more cinnamon to my diet, that's for sure.

MNS


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#120013 - 08/28/09 06:56 AM Re: leptospirosis filter [Re: midnightsun03]
DTape Offline
member

Registered: 11/23/07
Posts: 654
Loc: Upstate NY
crypto and giardia are also more resistant to chemical due the fact they are in cyst form in the water which protects them.

I think many municipal systems (US) are moving towards a combination of filter and uV.
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#120015 - 08/28/09 07:51 AM Re: leptospirosis filter [Re: midnightsun03]
lori Offline
member

Registered: 01/22/08
Posts: 2801
Originally Posted By midnightsun03
Ok, we're talking about apples and fish here.

Crypto and giardia are protozoa, not bacteria. They are much more resistant to chemical treatment because they are eukaryotes (i.e. complex organisms).



It's not apples and fish - it's a matter of being thorough. If you use one water treatment method because it's effective against one of these things, and you come down with the other, you'll wish you had two effective methods to start with. It's important to know what you are using and why. Some methods are partially effective, some are more broadly effective. Personally I'd like to know if something I do is going to involve risk so I can make an informed choice.

Hawaii is an area of high risk for leptospirosis. That doesn't mean there's no risk of other common bacteria, or other "bugs." Avoiding stagnant water is the suggested preventive measure.

"Leptospira organisms are small, filamentous, motile, spirochetes coiled around an axial filament ranging in size from 0.1 to 0.3 µm in width and 6 to 20 µm in length. They are easily killed by disinfectants, heat, drying, and pH values below 6 or above 8."

http://www.michigan.gov/dnr/0,1607,7-153-10370_12150_12220-26943--,00.html

I think I would filter and use Micropur.
_________________________
"In the beginner's mind there are many possibilities. In the expert's mind there are few." Shunryu Suzuki

http://hikeandbackpack.com

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#120016 - 08/28/09 08:44 AM Re: leptospirosis filter [Re: lori]
Dryer Offline
Moderator

Registered: 12/05/02
Posts: 3569
Loc: Texas
right. filter, then bleach if you don't trust the filter. you're on your own regarding pesticides.
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#120017 - 08/28/09 08:55 AM Re: leptospirosis filter [Re: lori]
Dryer Offline
Moderator

Registered: 12/05/02
Posts: 3569
Loc: Texas
The subject was "leptospirosis", not giardia and crypto, and....bleach is effective against those cysts if given enough time. It's used all over the world.
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#120018 - 08/28/09 08:59 AM Re: leptospirosis filter [Re: Fiddleback]
Dryer Offline
Moderator

Registered: 12/05/02
Posts: 3569
Loc: Texas
Quote:
Nor do municipal systems use it.



Actually, sodium hypochlorite is second to clorine gas in muni usage.
http://www.americanchemistry.com/s_chlorine/sec_content.asp?CID=1133&DID=4530&CTYPEID=109
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#120019 - 08/28/09 10:47 AM Re: leptospirosis filter [Re: Dryer]
Fiddleback Offline
member

Registered: 06/22/04
Posts: 478
Loc: Northern Rockies
The compound is used, yes. But the compound in the form of 'bleach', no.

And again, the trend is towards other, more effective treatments.

FB


Edited by Fiddleback (08/28/09 10:49 AM)
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"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution

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#120020 - 08/28/09 11:43 AM Re: leptospirosis filter [Re: lori]
midnightsun03 Offline
member

Registered: 08/06/03
Posts: 2936
Loc: Alaska
It is apples and fish... the question was about leptospirosis, which is a bacteria, and responders started talking about protozoa and viruses, which are managed entirely differently.

I agree that thoroughness is essential in many parts of the world anymore. Just a filter, or just chemical treatment might not be enough for many water sources. If you learn what you might encounter and know your enemy you can be prepared with the right treatment instead of a mixed bag you aren't sure will work.

MNS
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#120033 - 08/28/09 06:42 PM Re: leptospirosis filter [Re: Fiddleback]
Dryer Offline
Moderator

Registered: 12/05/02
Posts: 3569
Loc: Texas
Bleach is sodium hypoclorite. Bleach for short. No?
Actually "Bleach" (and they use the word) is used to shock home water wells the world over, as well as swimming pools.
_________________________
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#120054 - 08/29/09 11:38 AM Re: leptospirosis filter [Re: Dryer]
Fiddleback Offline
member

Registered: 06/22/04
Posts: 478
Loc: Northern Rockies
When discussing water treatments I'd say, 'No...sodium hypochlorite is not bleach.' Just as fluoride is not toothpaste and lye is not soap.

Household 'bleach' is generally 3-6% sodium hypochlorite and often contains scent additives which, of course, are not tested for, nor approved for, consumption. In contrast, concentration of the sodium hypochorite used by municipal water utilities generally runs 12-15%. It gained popularity with the utilities not only because it was easier to store than chlorine gas but was also much safer.

Utilities are slow to change and update their systems. But as the changes come, the older chlorine treatments are being replaced by chlorine dioxide which has been shown to be much more effective against buggies such as giardia and crypto. Some locations, which had large, multiple outbreaks of giardia traced to their 'treated' water, have not had a recurrence after switching to chlorine dioxide.

But don't let the word usage/definition issue cloud the issue. While bleach is great for surface disinfection and can be effective against baceria in water, the bottom line is...household bleach should not be relied upon as a water treatment if there is a concern for the presence of giardia or crypto (and probably any other virus as noted in one of the posts above).

FB
_________________________
"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution

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#120067 - 08/29/09 07:26 PM Re: leptospirosis filter [Re: Fiddleback]
Dryer Offline
Moderator

Registered: 12/05/02
Posts: 3569
Loc: Texas
Actually, sodium hypoclorite IS bleach and concentrations vary,

http://www.metrocouncil.org/directions/water/water2007/bleachJan07.htm

it comes unsented, its used by municiple waters systems second only to clorine gas,

http://www.americanchemistry.com/s_chlorine/sec_content.asp?CID=1133&DID=4530&CTYPEID=109

and is recommended by the Red Cross as emergency water treatment.

http://www.redcross.org/portal/site/en/m...00089f0870aRCRD

Fiddleback, where are you getting your data regarding municipalities switching to clorine dioxide? Crypto and giardia are easily filtered, so I don't see the point of chemical treatment for those bugs.
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#120078 - 08/30/09 01:06 PM Re: leptospirosis filter [Re: Dryer]
Fiddleback Offline
member

Registered: 06/22/04
Posts: 478
Loc: Northern Rockies
All collies are dogs but not all dogs are collies. We'll have to agree to disagree on the word usage of "sodium hypochlorite." grin

The takeaway from below is; 1)ClO2 is more effective than chlorine and its 'bleach' version, 2)while new to backpackers, ClO2 is time tested and, 3) the same can be said for UV treatment.

The water that emanates from water utilities is used/approved for irrigation, human consumption, dumping into surface waters or a combination of all three. Different standards/regulations are involved for the different uses. Municipal water providers generally use a multi-step process which includes sedimentation, biologic breakdown of the waste, filtration and chemical treatment. UV treatment is also being added.

As for municipal utilities trending to the use of chlorine dioxide:

U.S. municipal water systems started using chlorine dioxide in the mid-40’s (Treatment of Drinking Water with Chlorine Dioxide, www.oxy.com). The start time in Europe was about the same. But ClO2 is not without its own problems to include cost, handling safety, and by-products. Still, because of chlorine’s more troublesome human health issues and the subsequent changes in water quality regulations/standards, utilities have turned to ClO2 (ibid). “It is recognized as a superior water disinfectant alternative to chlorine and has become increasingly popular as a water purification treatment. Chlorine is being phased out due to growing concerns over its carcinogenic by-products, principally trihalomethanes (THMs)…In the U.S., the Safe Drinking Water Act and its subsequent amendments over the last 20 years have required dramatic improvments in the quality of municipal drinking water. These stringent new requirements have increased the use of chlorine dioxide in the U.S. while decreasing the use of chlorine as a water treatment chemical.” (Chlorine Dioxide – Water Treatment Technical Report: Chlorine Dioxide as a Water Purification Product and Safe Water Treatment Chemical, www.pristinewatertreatment.com/technical-info.html). More than 15 years ago, the trend was well established, “Approximately 700 to 900 public water systems use chlorine dioxide to treat potable water (Hoehn, 1992).” (EPA Guidance Manual, April 1999 Alternative Disinfectants and Oxidants, www.epa.gov/OGWD/mdbp/pdf/alter/chapt 4.pdf) That trend continues despite the moribund character of utilities. Here in Missoula County, our less-than-stellar (and often, less-than-compliant) wastewater treatment plant has, I think , adopted ClO2 treatment. I know that was the plan which also included the addition of UV treatment and that addition has been accomplished. Virtually all the sources here and others I saw specified giardia when referring to the higher effectiveness of ClO2.

FB
_________________________
"...inalienable rights...include the right to a clean and healthful environment..." Montana Constitution

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#120091 - 08/30/09 09:02 PM Re: leptospirosis filter [Re: Dryer]
Rick_D Offline
member

Registered: 01/06/02
Posts: 2801
Loc: NorCal
So far I've only found a U.S. reference to Niagara Falls, New York as using ClO2 municipal treatment. I presume there are others but it's clear that it hasn't been widely adopted. In California, several very large systems have switched to chloramine, which is much more stable and persistent in the distribution system than chlorine, but presents its own set of problem byproducts, plus it's quite toxic to aquatic life. And it's green.

Cheers,

Rick
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#120100 - 08/31/09 09:47 AM Re: leptospirosis filter [Re: Dryer]
ringtail Offline
member

Registered: 08/22/02
Posts: 2296
Loc: Colorado Rockies
My municipal water is safe after sand filtering. The chlorine is added to keep it potable in the tranmission system. Water in the system, especially fire hydrants, can get stagnant
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#151892 - 06/25/11 09:49 PM Re: leptospirosis filter [Re: mantashrimpman]
mantashrimpman Offline
newbie

Registered: 08/26/09
Posts: 4
Loc: honolulu
haha ok guys so the consensus for me not to contract leptospirosis on my next backpacking trip would be to chemically treat the water? kalalau valley in kauai is known for having problems with lepto and i was looking for a way to filter without having to make the water taste bad with chemicals. But if there is no other way, drinking water that doesn't taste spectacular is still better than getting flu like symptoms 11.2 miles away from my car.

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#151959 - 06/27/11 01:54 PM Re: leptospirosis filter [Re: mantashrimpman]
Heather-ak Offline
member

Registered: 07/11/10
Posts: 597
Loc: Fairbanks, AK
From http://www.leptospirosis.org/topic.php?t=15

Boiling water
The bacteria (and almost all other pathogens likely to be found in rivers and lakes) are killed by boiling the water for a few minutes - so this works best on small volumes that you wanted hot to begin with. Boiling is the first choice for camping trips and also means that food cooked at or above boiling point (such as meat) will also be rendered safe in the process. It of course needs a power source, but it doesn't involve chemcials so is acceptable to people wanting the least impact on their diet. Boiling is not an option for a general household water supply, but of course makes boiling water for hot drinks safe.

Iodine tablets
Water purification tablets that use iodine are very effective too, and don't need a heat source, but can leave a taste that some people find unpleasant. They are however easy to use and light to carry, so are ideal for long hikes and expeditions to remote areas. It's not an option for large volumes or a household supply.

UV sterilisers
These are also very effective against leptospira (and most other pathogens), and can be bought on all scales. Permanent systems for processing flowing water in a domestic house are available, but can be expensive and use electricity. Portable devices for camping and backpacking are also available, resembling a small flashlight or pen, and these can be used to sterilise a single cup of water - but need batteries. The advantage of using UV is that there are no chemicals involved, and the electricity required is less than for boiling the same volume. It does require the sample to be transparent though, so can't be used on things like milk.

Chlorination
Water not used for drinking - such as swimming pools and ornamental features, can be protected by adding dissolved chlorine. In commercial pools this is a complex engineering process, but for private pools it's usually added in the form of tablets. It's important to keep the chlorine levels high enough to be effective but not too high, so testing kits (using color-changing paper) are available. Leptospirosis is killed by the concentrations of chlorine used in commercial pools and most private ones, assuming the owner follows the instructions on the packet!

Filtration - does not work!
Leptospira are incredibly small - they can pass through the pores in water filters, even those that claim to remove bacteria. They will pass easily through filters with a pore size of more than 0.2 micron, including membrane and charcoal types. High-pressure laboratory filters with a pore size of less than 0.1 micron will block them, but the typical hand-held water filters used by hikers, pool filters and the fitted cannisters used in some domestic kitchen applicanes are useless at removing leptospires - they are often used to separate leptospires from other bacteria when preparing samples for research, as the leptospires pass through but other bacteria don't!

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#151967 - 06/27/11 03:17 PM Re: leptospirosis filter [Re: Heather-ak]
OregonMouse Online   content
member

Registered: 02/03/06
Posts: 6372
Loc: Gateway to Columbia Gorge
Originally Posted By Heather-ak
From http://www.leptospirosis.org/topic.php?t=15

Iodine tablets
Water purification tablets that use iodine are very effective too, and don't need a heat source, but can leave a taste that some people find unpleasant. They are however easy to use and light to carry, so are ideal for long hikes and expeditions to remote areas. It's not an option for large volumes or a household supply.


OK, time for my periodic rant about iodine. My own experience is that after a month of use (only on weekends) I developed an all-over rash consisting of deep lesions (lichen planus) that left permanent scars. To this day I still cannot eat anything with even trace amounts of iodine. That means no seafood, no food prepared with iodized salt (which means most restaurants and most food prepared in peoples' homes are out), nothing with added iodine. Until very recently, it meant I could never have an angiogram (there are now alternatives available).

I found that this allergy or sensitization or whatever you want to call to iodine it is not at all uncommon. I wouldn't wish this condition on my worst enemy!

Per the Centers for Disease Control:
Quote:
Iodine has physiologic activity (it is used by the thyroid), so WHO recommends limiting iodine water disinfection to a few weeks of emergency use. It is not recommended in persons with unstable thyroid disease, known iodine allergy, or pregnancy (because of the potential effect on the fetal thyroid).


More from the CDC (same article as above):
Quote:
some common waterborne parasites such as Cryptosporidium, are poorly inactivated by halogen [iodine and chlorine bleach/sodium hypochlorite] disinfection, even at practical extended contact times.


I strongly recommend never using iodine! Chlorine dioxide tablets are much safer, kill all bacteria and viruses, and kill protozoans given sufficient contact time. Used in conjunction with a filter of 1.0 microns or smaller, chlorine dioxide plus flitration is by far the safest method other than boiling.

IMHO, any source that recommends using iodine for water disinfection and doesn't even mention chlorine dioxide is very poorly informed.


Edited by OregonMouse (06/27/11 03:23 PM)
_________________________
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey

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#151972 - 06/27/11 04:02 PM Re: leptospirosis filter [Re: OregonMouse]
Rick_D Offline
member

Registered: 01/06/02
Posts: 2801
Loc: NorCal
Can't stand the stuff (iodine) myself--smells like an emergency room, not something I want to drink.

For peace of mind, i'll recommend either UV or one of these:

Sawyer 0.02 µm filter

Cheers,
_________________________
--Rick

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#158382 - 12/07/11 03:17 AM Re: leptospirosis filter [Re: Rick_D]
mantashrimpman Offline
newbie

Registered: 08/26/09
Posts: 4
Loc: honolulu
what about the msr miox? will this purifier be effective against the leptospirosis virus?

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#158385 - 12/07/11 08:52 AM Re: leptospirosis filter [Re: mantashrimpman]
Paulo Offline
member

Registered: 01/27/11
Posts: 158
Loc: Normally Pacific Northwest
Sawyer does a virus filter!
_________________________
Without a doubt, the hardest thing of all in a survival situation is to cook without the benefit of seasonings and flavourings. - Ray Mears

http://theoutdooradventure.net

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#158419 - 12/07/11 07:43 PM Re: leptospirosis filter [Re: mantashrimpman]
CamperMom Offline
member

Registered: 01/04/02
Posts: 1186
Loc: Eastern MA, USA
I hadn't even heard of leptospirosis and just did a quick read. It is present in animal populations, infecting small numbers at a time. It seems to more common in tropical areas, but with the modern world's convergent paths, it has spread. There have now been human cases reported in Massachusetts. Oh, happy days!

As I said, I just did a quick read. Leptospires are spirochetes, not a viruses, in case anyone really cares. I think in my 40+ year old textbooks, they may have been written up as not bacteria, Maybe because of the flagella, like protozoans have. I see they are classified as a spiral bacteria. Besides Leptospirosis, spirochetes are responsible for Lyme disease and Syphillus. Yea!

I think I am going to continue to treat water collected along the trail...

CM

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#158440 - 12/08/11 10:55 AM Re: leptospirosis filter [Re: mantashrimpman]
Steadman Offline
member

Registered: 09/17/09
Posts: 510
Loc: Virginia
mantashrimpman

Oh, that sounds like a great trip. When I move home again, I want to do that hike.

Everything proposed will work to keep leptospirosis out of your drinking water.

- A backpacking filter will work.

- Chemicals (bleach, chlorine dioxide tablets, and iodine) will work if you follow the directions and mind the amount of exposure time of the chemicals to the water.

- Boiling your water will work.

- A UV purifier will work.

If you really want to be cautious, combining two methods (filtering and then using chemicals is the most common combination) will work but you will have to carry more stuff.

Leptospirosis is a problem in all fresh water in Hawaii. If you ever went swimming at the swimming hole off the Dupont trail in Tantalus, or jumped off of Mauanawili Falls, you risked exposure. The good news is that you live in Hawaii, and the docs know what leptospirois symptoms look like.

Aloha

Steadman

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