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River Blindness Revealed in Urine
ScienceNOW ^ | 26 February 2013 | Kai Kupferschmidt

Posted on 02/26/2013 6:56:54 PM PST by neverdem

Enlarge Image
sn-riverblindness.jpg
Blind spot. The parasitic worm Onchocerca volvulus (inset) can move to the eyes and cause blindness as in these two patients in Guinea-Bissau. Onchocerciasis is considered a neglected tropical disease.
Credit: Harry Anenden/WHO; (inset) CDC

A small parasitic worm is one of the leading causes of blindness in the world. But now researchers have discovered a molecule in the urine of African patients that could help diagnose those infected with the parasite and help eliminate the devastating disease known as river blindness.

The illness, scientifically known as onchocerciasis, is caused by the parasitic worm Onchocerca volvulus. Black fly bites transmit the worm's larvae to humans, and the larvae grow into adults that form nodules beneath the skin all over the human body. Female worms then produce large numbers of larvae called microfilariae that move to the skin to be ingested again by biting black flies. The larvae can also enter the eyes, however, causing blindness. An estimated 500,000 people, mostly in sub-Saharan Africa, have lost their sight because of the parasite.

The World Health Organization has set a goal of eliminating the disease from the Americas by 2017 and from Africa by 2025. Infections with Onchocerca volvulus can be treated with ivermectin, which kills the larvae but not the adult worms. The antibiotic doxycycline, which kills a bacterium called Wolbachia that lives symbiotically with the worm, has shown promise in killing adult worms as well and is sometimes used alone or in combination with ivermectin. Current control strategies rely on the repeated mass treatment of potential patients with ivermectin, however, as diagnosis is often difficult. In some cases, the surviving adult worms can spawn a new generation of larvae.

The gold standard for diagnosis is a so-called skin snip. "You basically cut off a little bit of skin and then you can see the larvae of the worms," says Daniel Globisch, a researcher at the Scripps Research Institute in San Diego, California, and one of the authors of the study. The method is not very sensitive however, particularly in less intense infections, which are becoming more frequent with progress in controlling the disease, says Maria-Gloria Basáñez, a researcher in neglected tropical diseases at Imperial College London.

Now, Globisch and his colleagues have identified a new way to test for the disease. They compared the amounts of hundreds of molecules found in urine samples of infected and healthy Africans and discovered one striking difference: An unknown molecule was present at levels six times higher in the urine samples of infected individuals than in samples from healthy people. The researchers identified the molecule as the remnant of a neurotransmitter that larval stages of the worm excrete and that is then broken down in the human body before being excreted in the urine, they report online this week in the Proceedings of the National Academy of Sciences.

"Finding such a marker was really lucky," Globisch says. "Using this molecule, we could make a diagnostic test that can be put in a backpack and diagnose whether people are infected or not." That would allow doctors to "specifically treat those who are still infected," he says. Globisch estimates that such a portable diagnostic test could be ready in 3 years.

The researchers' approach "to identify biomarkers is certainly elegant and innovative," writes Michel Boussinesq, an onchocerciasis expert at the Institute of Research for Development in Montpellier, France, in an e-mail. But urine samples may not be easier to collect in an African village than skin snips, he cautions. An experienced researcher might collect 40 skin snips in an hour, he says, but with urine the researchers have to wait until each person can produce the sample. To be sure that the new technique provides an advantage, "it would be necessary to compare the quantitative results of the technique described in the paper, and the quantitative results of skin snips," he says.



TOPICS: Culture/Society; News/Current Events; Testing
KEYWORDS: microbiology; onchocerciasis; parasitology; riverblindness

1 posted on 02/26/2013 6:57:06 PM PST by neverdem
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To: neverdem

The same drug is used to prevent heartworm in dogs. The dog has to be tested though, because if there are already worms, the dog could die from the medication.

At least that is the general theory.


2 posted on 02/26/2013 7:01:05 PM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: neverdem

Scratch visiting there off my “bucket list”!


3 posted on 02/26/2013 7:02:38 PM PST by BenLurkin (This is not a statement of fact. It is either opinion or satire; or both)
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To: neverdem

What makes these dopes think that this disease has not trans mutated out of Sub Saharan Africa and spread all over the world via the travel of all of the Relief Agencies? The do gooders leave and the disease doesn’t spread?


4 posted on 02/26/2013 7:06:24 PM PST by acapesket
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To: left that other site

Ivermectin will rip your liver to shreds if not administered carefully.


5 posted on 02/26/2013 7:09:56 PM PST by acapesket
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To: acapesket

Indeed.

Linda-the-dog gets ONE tablet, calculated by her weight, per month and only after a blood test.

It’s hard to imagine this kind of care and precision administering the drug in the African back-country.


6 posted on 02/26/2013 7:13:39 PM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: left that other site

If you are treating your dog and/or cat for heartworm, your are also treating a bunch of Africans for river blindness: http://www.americanscientist.org/issues/page2/ivermectin-and-river-blindness


7 posted on 02/26/2013 7:14:11 PM PST by Western Phil
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To: Western Phil

Well, that’s good to know.

I hope they are using the same precautions that i use with my dog.


8 posted on 02/26/2013 7:16:14 PM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: Mother Abigail; EBH; vetvetdoug; Smokin' Joe; Global2010; Battle Axe; null and void; ...
State deer herd hit with hemorrhagic disease (LA)

FDA Approves Genentech’s Kadcyla (Ado-Trastuzumab Emtansine), the First Antibody-Drug Conjugate for Treating HER2-Positive Metastatic Breast Cancer

Sweat protects us from dangerous bugs

FReepmail me if you want on or off my combined microbiology/immunology ping list.

9 posted on 02/26/2013 7:40:37 PM PST by neverdem ( Xin loi min oi)
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To: neverdem

For a second, upon just reading the title/excerpt on the forum, I thought the treatment was pouring an African’s urine into the eyes in order to kill the parasite.


10 posted on 02/26/2013 7:49:38 PM PST by Repeat Offender (What good are conservative principles if we don't stand by them?)
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To: neverdem

Just a note of caution. Ivermectin is contraindicated for certain dog breeds, collies being one of those groups.


11 posted on 02/26/2013 8:05:05 PM PST by rmh47 (Go Kats! - Got eight? NRA Life Member])
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To: left that other site

I believe in the case of a dog with heartworms, the dead worms can come loose, clog stuff up and cause a stroke. The dog must be sedated and kept still while the dead worms are disolved or adsorbed into the system.


12 posted on 02/26/2013 8:09:51 PM PST by Slump Tester (What if I'm pregnant Teddy? Errr-ahh -Calm down Mary Jo, we'll cross that bridge when we come to it)
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To: neverdem

Urethrae!


13 posted on 02/26/2013 8:18:08 PM PST by Vendome (Don't take life so seriously, you won't live through it anyway)
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To: Repeat Offender

Not to mention the confusing statement that the black fly bite transmites larvae to a human which in turn turns into a worm which is then ingested again by biting black flies. So how do they survive?


14 posted on 02/26/2013 8:42:48 PM PST by Inyo-Mono (NRA)
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To: left that other site

“The same drug is used to prevent heartworm in dogs...”

Are you referring to Ivermectin? Ivermectin is commonly used to rid horses of parasites. We have horses, but we do not use it because diatomaceous earth is better, and is not hard on the horses.


15 posted on 02/26/2013 8:47:39 PM PST by GGpaX4DumpedTea (I am a Tea Party descendant...steeped in the Constitutional Republic given to us by the Founders.)
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To: GGpaX4DumpedTea

diatomaceous earth? Really? That would be cool. The wife uses the paste on big horsey...

I knew it was good for open air insects. It operates under the same principle (making them hemorrhage?) for internal?


16 posted on 02/26/2013 9:16:16 PM PST by Axenolith (Government blows, and that which governs least, blows least...)
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To: Slump Tester

Oh Dear..That’s awful. ((((shudder))))

I live in a semi-tropical place, and we have to be very careful about heartworm in dogs. Lots of mosquitoes, which carry the microfilarae, abound in the Everglades!

Not to mention Alligators, Crocodiles, and our newest pest, Burmese Pythons.


17 posted on 02/27/2013 4:38:22 AM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: GGpaX4DumpedTea

Yes. Ivermectin.

That is interesting about your horses. It would be really nice if a more natural product could be successful with dogs...AND Humans!

Ivermectin is powerful stuff.


18 posted on 02/27/2013 4:41:28 AM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: neverdem

“Skin snips” huh?

Don’t they do that in Jewish hospitals to newborn male babies?

/Sarc


19 posted on 02/27/2013 4:50:48 AM PST by DH (Once the tainted finger of government touches anything the rot begins)
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To: left that other site

“It would be really nice if a more natural product could be successful with dogs...AND Humans!”

There is...the same diatomaceous earth (DE) that we use for the horses. Works for cattle, dogs, cats and people. We buy DE in a 50 lb bag, and it is food grade. We pay about $30 a bag at the feed elevator. Note...Do NOT use the stuff that is made for swimming pool filters.

DE also kills insects.


20 posted on 02/27/2013 7:01:36 AM PST by GGpaX4DumpedTea (I am a Tea Party descendant...steeped in the Constitutional Republic given to us by the Founders.)
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To: GGpaX4DumpedTea

Thank you for your kindness!

I will order some now!
:-)

OH HOW I LOVE FR!!!!!!!!!!!!


21 posted on 02/27/2013 7:20:10 AM PST by left that other site (Worry is the darkroom that developes negatives.)
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To: neverdem
Another great Obama mystery finally solved!

Flies land on Obama's face photo Obama_Fly_Guy_zps25506b2e.jpg

22 posted on 02/27/2013 9:13:10 AM PST by SteveH (First they ignore you. Then they laugh at you. Then they fight you. Then you win.)
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To: acapesket

it is one of the medications used in worming goats, never caused any problems in goats...But some of the meds are given by injection, calibrated to weight, don’t remember if it was ivermectin or not....


23 posted on 02/27/2013 1:10:20 PM PST by goat granny
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