Effectiveness of Steripen UV against cysts: Giardia and Crypto

[Bruce Tolley]

Has anybody seen empirical data on the effectiveness of Steripen UV treatment against cysts.  The label on the box just claims 99.9% effective against protozoa, a class of organisms which includes cysts.

I have started to read the material on the Hydro-Photon web site, and one paper just addressed UV in general and the other just tested with a non cyst organism.

Since Giardia are large, 6 to 10 microns in diameter I think and Crypto a bit smaller but still large 4 to 6 microns it seems that you would get better results with UV treatment by pre-filtering with the Steripen 4 micron filter.

Cheers.

 

[Paul S.]

The UV won’t kill the larger organisms but it will render them unable to reproduce and completely harmless.

[Bruce Tolley]

Correction to above: the prefilter screen is 40 microns.

 

[Ben H.]

Did you see this paper?:

https://www.steripen.com/stuff/contentmgr/files/1/02ac755595468c5da0c8d224bef3c2db/misc/coccidianparastites.pdf

Since the pre-filter is bigger than these organisms and the Steripen by itself is effective, it wouldn’t hurt but does not seem like a necessary pre-treat.

[Bob K]

http://www.travelmedicinejournal.com/article/S1477-8939(15)00174-X/fulltext

[Bruce Tolley]

Thanks Bob

I had not seen this specific article. But the test organisms were various bacteria such as E coli not crypto or giardia. UV seems very good against bacteria.

Cheers

Bruce

 

[BlackHatGuy]

Does this help?

[James Marco]

Thanks, Doug. Yes, UV is more effective than Iodine, Chlorine Dioxide or MIOX. No prefilters were used.

[Donna C]

From Isle Royale website about their water:

SteriPENs and other UV purifiers have not been manufacturer-tested for a common parasite found on Isle Royale and cannot be considered effective.

There is no mention as to what the parasite is.

[Bruce Tolley]

Doug

Great article. Of course one study does establish gospel truth but very informative. (Since Scientific findings must be reproducible.) Now is there one about UV and Giardia?

Cheers/Bruce

[Ken Larson]

https://www.steripen.com/stuff/contentmgr/files/1/02ac755595468c5da0c8d224bef3c2db/misc/steripen_sidewinder_u.s.e.p.a..pdf

[John S.]

Isle Royale NP has long warned about Ecchinococcus species in their waters with only filtering or boiling appropriate because of the thickness of the cyst wall.

[Ryan Jordan]

Here’s some unpublished, unvalidated, and not-peer-reviewed info based on some under-the-table water research I did in my lab when I was working as a disinfection technology research professor years ago.

Tapeworm (Echinococcus spp.) eggs are pretty robust. I found that both bleach and Aqua Mira actually disinfected up to 1log (90%) in clear, warm (room temp) water. A chemical similar to what is now distributed as AquaTabs resulted in a 2log (99%) reduction in active eggs.

UV was VERY effective – 3log+ (99.9%+). I think we actually used the Gen1 Steripen. Again, in warm, clear water. We didn’t test in murky or cold water, so I can’t extrapolate for you.

However, any decent prefilter *should* take care of it. These eggs are pretty big. If I recall, they something like 25 microns in diameter, and most of these prefilters have pore sizes that are one fifth to one tenth of a size of that. Even coffee filters have pore sizes of 20 microns or so and we found these to remove quite a lot of bacteria that were down in the 1-2 micron size range. Probably as a result of “electrical charge attraction” or “physical adsorption” I think the chemists call it.

In one of our initial studies of “how prevalent is _____ (pathogen) in the backcountry…?”, the highest incidence of tapeworm eggs we found were in springs down by Springer Mountain, and at some popular lakes in the High Sierra. Also, a City-owned swimming pool. Ugh. And ick. And eww.

And to reiterate: boiling is really the only fool proof method. What if your filter has a defect that is 50 or 100 microns in diameter? It’s much more common than you think, especially with these fiber prefilters. Ceramic filters tend to be more reliable, unless you’ve cracked one during a freeze-thaw cycle.

So much going on!

[Bruce Tolley]

@ Ken

The conclusion seems a bit odd to me. They state that the EPA requirement is to test against 3 classes of organisms but they did not test against protozoan cysts. But the Steripen should work since cysts are easier to kill than bacteria. Why not just include cysts in the test suite?

@ Ryan

Thanks for the information. I remember some of the very informative material you shared a few years ago on BPL about biofilms in lakes and their ability to clog filters.

[John S.]

Ryan, thanks for the info.

[James Marco]

Ryan’s post shows how dangerous tapeworms actually are. While your digestive system is, perhaps, the strongest method out there for dealing with stuff on a personal basis, it is not fool proof. Tapeworm eggs are one that it is NOT worth dinking around with, where ever it is found…and, you really do not know without a lot of testing.

While most results allow a statistical test to the satisfaction of the tester, 99% or 99.9% or 99.99% always means some will get through the treatment being tested. For Giardia, this is not a problem. It generally takes 5-10 individual pathogens to infect you. If you *do* get infected, you likely get a case of diarrhea for a few weeks and it goes away. Not so with tape worms. All it takes is *one* egg. Your digestive system is no help and will only give it a nice place to grow. A statistical result is not good enough.

Once in your system it will bore through your intestine and eventually into some part of your body where it will create a cyst. Muscles, heart, liver, lungs, brain, etc., it will get into one of them. After a few years (it continues to grow in size) it could be disturbed, causing a severe alergic reaction (yeah, there is some fancy medical term for it) and cause death. Not something you get over or detect.

[Bruce Tolley]

@ Ryan

On coffee filters as pre-filters, are you referring to paper filters or the metal “gold” type of filter that comes with many household drip machines and MSR sells one for backpacking.

[Ken Larson]

Back in 2008 I had emailed SteriPEN concerning the same issue currently discussed because of my immunocompromised immune system due to the stem cell transplants I had under gone and I was planning to do some backpacking and at that time the SteriPEN was the device I was going to use. The following return I received will provide information I believe will provide information for you to make your decision on how to proceed..

Hi Ken,

Thanks for the e-mail.

I have copied a response from Miles Maiden, inventor of the SteriPEN, when he was asked this same question.

“We have tested SteriPEN only against bacteria, viruses and the protozoa Cryptosporidium and Giardia. We have never tested against worm eggs – so unfortunately I cannot give you a definitive answer with regard to UV treatment in this case. As to our pre-filter – we make no microbiological claims about it as it is really just intended to remove large particulates. The pore size is 4 microns by 4 microns square – it is a nylon material comparable to a coffee filter. While there is not a lot of literature on UV treatment of worm eggs, you may be interested to look at the following web site:
http://parasitology.informatik.uni-wuerzburg.de/login/n/h/j_010- 0391.html. linked

When reading this keep in mind that the UV wavelengths emitted by SteriPEN are in the Mercury band with a primary energy output at 254 nanometers (in the UV-C range). Also, SteriPEN’s 1 liter treatment time is 90 seconds and generally delivers over 100 milijoules/sq.cm.
during this dose. Below is a quote from the above site: “The UVC lamp significantly inhibited the infectivity of taeniid eggs in rats. The Bonferroni/Dunn test for the mean number of cysts in the control group and the groups exposed to the UVC lamp was significant ( P<0.0001), except for the group at an exposure of 30 s (30 mJ/cm 2 at 254 nm). This means that the significant effect of
the UVC lamp commences at an exposure duration of 90 s (90 mJ/cm 2
at 254 nm).”

So, in a nutshell, I am sorry that I cannot specifically point you to SteriPEN testing on worm eggs. And we probably will not do this testing in the future as it involves animal testing (we did animal testing for Crypto and Giardia because there was no alternative, however we decided we did not want to do animal testing again). But for whatever it is worth, the above referenced link does indicate
that UV-C can have a disinfecting effect on worm eggs at the energy levels SteriPEN provides.

Please let me know if you have any further questions.

Best regards,
Miles Maiden – CEO, CTO ”

Aaron Cox
Technical Support
Hydro-Photon, Inc.

If you are wondering how I proceed…….I use a SAWYER SP 125 PURIFIER in a gravity mode as this device physically removed viruses that I was protecting myself from along with the the other “critters”. at a >5.5 log (99.9997%) rate exceeding EPA and NSF recommendations.

[Donna C]

Well now I am concerned as to how I should treat the water on Isle Royale this fall. I use Sawyer squeeze, and I also have tablets as a backup. I can boil for meals but what about during the day?

[Ken Larson]

@Donna I will be on Isle Royale this Fall and plan to use KATADYN BeFree Filter  with tablets as a backup as I did in 2017 with no issues. In the past I used SAWYER SQUEEZE FILTER and had no issues also. Both instance above I back flushed daily.

[Donna C]

Ken, thanks. I have the Be Free as well and like it much better.  We might bump into each other this Fall on the island.

[Ken Larson]

@Donna..I .forgot to mention that there were Blue-Green algae no contact warning issues last year by the NPS cautioning hikers and packrafter on their website and with signs very plainly posted on trails and water portages in the vicinity of the contaminated waters..

The presence of cyanobacteria in Lake Richie was first noted on August 20, 2017 as part of inland lake water quality monitoring (https://science.nature.nps.gov/im/units/glkn/monitor/lakes.cfm). The presence of cyanobacteria was confirmed using microscopical analysis; samples for toxins were collected and have been sent to a laboratory for analysis.

Something to note that not all cyanobacteria are toxin-producing, however those identified in Richie and Chickenbone are species capable of producing toxins andwere microscopically identified the Chickenbone Lake cyanobacteria as the genus Dolichospermum (genus formerly known as Anabaena). The Lake Richie cyanobacteria were identified as Lyngbya, Dolichospermum, Aphanizomenon, and Woronichinia.

This issue and past issues  are still a puzzle to resource managers, and a study was initiated in 2012 by the USGS and the Great Lakes Inventory and Monitoring Network to determine what factors are linked to the cyanobacteria blooms. So keep in touch with the NP Web Site especially in late August and early September as they will post a warning if the blooms are present……OR avoid these two lakes as other have not been targeted with the algae to date. 

I’m planning to be packrafting in those two lakes in early September so this is an issue for me if the cyanobacteria appear once again.

[Donna C]

Good info, Ken. Thanks. I will share it with the others who are coming along. I will be there mid September.

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