A Guinea worm is a worm that enters the body through drinking water but comes out, very painfully, through the skin. It’s easy to find info on it through web searches. Here’s one page:
http://www.cartercenter.org/guineawormprogram.html
What I haven’t been able to find out is how the worm gets from the intestines to the skin. I’m guessing it probably gets into the bloodstream but I’m not sure.
Any ideas?
If I remember right from my parasitology class all those years ago, you are correct, it is through the blood vessels.
The guinea worm can be removed by slowly winding the protuding part around a stick, and some theorize that might be the origin of the caduceus symbol used by pharmacists.
Hijack/Digression:
There are attempts afoot to exterminate the guinea worm. As a Green/environmentalist of the wildlife-preservation variety, I object to this. Just because a species is human-parasitic doesn’t negate its right to exist.
Any thoughts on this?
Arnold: What I’m wondering is whether or not the worm somehow navigates the bloodstream. Although it doesn’t say say specifically on the page I linked I get the impression that the worm itself isn’t fatal (complications can be). But what would happen if it settled in some place like the heart or the brain? Does it somehow avoid those places?
The following is not a flame, nor is it intended to be sarcastic:
How far does the desire to preserve all life forms go, I wonder? Would you, for instance, object to the elimination of smallpox, since that organism should also have a right to exist?
The Prince: “Did you kill Jahamaraj Jah?”
Lady: “Yes.”
The Prince: “My Gods! Why?”
Lady: “His existence offended me.”
I think the debate, as specific to the guinea worm, is moot since I doubt that it could be completely eliminated.
Even if you prevented it from reproducing in humans, the worm infects a large number of different mammals. It also is prevalent in various water sources. That is far too large of an animal and environmental reservoir to even begin to eliminate it completely.
Smallpox, in contrast, only infects humans. By preventing it from infecting humans we have effectively eliminated it from the wild.
I have started a thread in GD for anyone who wants to continue foolsguinea’s debate:
Do species have a “right” to exist?
Gypsy: Tom, I don’t get you.
Tom Servo: Nobody does. I’m the wind, baby.
“Even if you prevented it from reproducing in humans, the worm infects a large number of different mammals. It also is prevalent in various water sources. That is far too large of an animal and environmental reservoir to even begin to eliminate it completely.”
Nope. There are no known non-human reservoirs. That is why a serious attempt at eradication is being attempted.
As for the migration of the worm: The worm doesn’t exactly migrate from the intestines to the skin. It is worm larvae that are ingested, inside of copepods (water fleas). The larvae are liberated from the copepods in the stomach and then pass through the wall of the duodenum (first part of the small intestine) into the viscera (guts) where they grow to be adults. Somehwere along the line, the males and females get together long enough to mate after which the female “migrates” to a position just under the skin of the legs, waiting for the leg to be immersed in water which stimulates her to expel her eggs.
I don’t know the details of how the female finds her way around in side the body. You’ll have to go to a parasitology text to find that out. But I can say that there are lots of little critters that are quite good at navigating inside the bodies of their hosts. (Ever hear of loa-loa, the “eye worm.”)
Yeah, I beg to differ on several of your points:
From Encyclopedia Brittanica:
There is a massive push to elimate the disease dracunculiasis, not the Guinea worm:
As you can see from [url=http://www.cdc.gov/ncidod/eid/vol4no3/hopkins.htm]this website** from the CDC, all of the measures being taken are to prevent humans from ingesting the worm, not to eradicate the worm from the wild:
Gypsy: Tom, I don’t get you.
Tom Servo: Nobody does. I’m the wind, baby.
From what I read, the guinea worm is quite clever in that when the worms break through the skin, the host will often find relief by sticking his or her lower leg (where the worm usually makes its reappearance) in water. Then the worms can go contaminate the water supply again.
I also read that India has declared itself Guinea worm free.
You say I’m blind, I say you’re hallucinating.
Alphagene:
Check out "Progress Toward the Eradication of Dracunculiasis (Guinea Worm Disease): 1994 from the April-June 1995 edition of Emerging Infectious Diseases (Vol 1, No. 2) which can be found at: http://www.cdc.gov/ncidod/eid/vol1no2/ruiz.htm
Here is a quote: “An understanding of the factors that contribute to the emergence of dracunculiasis provides the basis for the current elimination program. GWD can be eradicated for several reasons: 1) there is no human carrier beyond the 1-year incubation period; 2) there is no known animal reservoir; 3) detection of patent infections (i.e., worms protruding from skin lesions) is an easy way to assess the presence of the disease in communities, and protrusion of the worm is required for transmission; 4)
transmission of the disease is markedly seasonal, facilitating the timing and effectiveness of surveillance and control interventions, including containment of cases; 5) the methods for controlling transmission are simple, and 6) the disease is well recognized by the local population in areas where it is endemic.” I repeat point #2: “There is no known animal reservoir.”
“There is a massive push to elimate the disease dracunculiasis, not the Guinea worm:” I’m afraid it’s the same thing. If human dracunculiasis is eradicated, Dracunculus medinensis will be exterminated. If eradication is successful, the only hope for the guinea worm will be if people step forward to serve as volunteer hosts. How about it foolsguinea? If D. medinensis has, as you say, a right to exist, surely it has as much right to exist in you as it does in some impoverished Yemeni or Nigerian.
“As you can see from [url=http://www.cdc.gov/ncidod/eid/vol4no3/hopkins.htm]this website** from the CDC, all of the measures being taken are to prevent humans from ingesting the worm, not to eradicate the worm from the wild:” It is not necessary to try to eradicate the worm from “the wild” since it only exists in human communities.
What were the other points you beg to differ with me on?
But it’s not restricited to one host!!!
Admittedly, the EB reference is the only reference I saw that gave any indication of the host range of this organism, but no reference that I saw indicated that humans were the only host.
As I am not trained in detail in parasitology, however, I am willing to concede if someone can find a reference stating otherwise.
And the host doesn’t immerse itself in water. It stands in it. Or sticks whatever part of its body is infected. While many parastic organisms have an aquatic phase to their lifecycle, I don’t think that’s necessarily evidence for the AA hypothesis. It just suggests that humans, like most terrestrial animals, spend a lot of time near water and that parasitic organisms have evolved to take advantage of that.
Plus, AFAIK, this is an unusual spread mechanism. Most parasitic nematodes do not rely on the host being even partially underwater. They are generally either crapped out by the host or rely on mosquitos or biting flies for exit from the host.
Gypsy: Tom, I don’t get you.
Tom Servo: Nobody does. I’m the wind, baby.
According to “Control of Communicable Diseases in Man,” a pretty reliable resource, “Reservoir - Man. There are no significant animal reservoirs.” Doesn’t rule out other animal hosts, but I think these things have a real taste for humans.
Jill
http://www.cdc.gov/ncidod/EID/vol1no2/ruiz.htm
[[When the ingested copepods are killed by the digestive juices in the stomach, the larvae are released and move to the small intestine. They penetrate the intestinal wall and migrate to the connective tissues of the thorax, where male and female larvae mature and mate 60 to 90 days after infection. Over the next year, female worms grow to maturity, reach a length of 70 cm or more (2-3 feet), and slowly migrate to the surface of the body.]]
Yikes! I’d give up my animal rights activism if I lived anywhere near these noodles.
[[As the worm emerges through the skin lesion, the affected person pulls it out slowly and carefully, usually by winding a few centimeters each day on a stick. This very painful process may last many weeks.]]
Yeah… I’m gettin me one of those “Save the Guinea Worm” bumper stickers first thing tomorrow morning.
Hm, hell of a time to simulpost.
Don’t take my disagreement personally, Yeah, we just had contradicting sources regarding the worm. As I said in my last post, you found a CDC reference refuting my EB one. I am more likely to trust the CDC than EB. In fact I just emailed EB with your reference pointing out their conflicting information.
It’s just that you made your original statement regarding the host range without references and I always question statements made that way. Hell, looking back I noticed I did the same thing. Nothing personal.
Your reference makes that seem true, as far as dracunculiasis is concerned. But in general, eradication of a disease is possible without eradication of the causative organism. If every human on earth from now on was vaccinated with the tetanus toxoid (easier said than done), we would eliminate tetanus as a disease without having exterminated Clostridium tetani. It is conceivable, in general, to strive for elimination of a disease without having to eliminate the organism.
Gypsy: Tom, I don’t get you.
Tom Servo: Nobody does. I’m the wind, baby.
What’s a significant animal reservoir? A herd of boar with high self-esteem? So confusing.
Oh gross, Jill. They were creepy enough before you anthromoporphized them.
Gypsy: Tom, I don’t get you.
Tom Servo: Nobody does. I’m the wind, baby.
“According to ‘Control of Communicable Diseases in Man,’ a pretty reliable resource, ‘Reservoir - Man. There are no significant animal reservoirs.’ Doesn’t rule out other animal hosts, but I think these things have a real taste for humans. Jill” - JillGat
According to the 17th ed of CCDM, just published, the reservoir is: “Humans; there are no known animal reservoirs.”
“But in general, eradication of a disease is possible without eradication of the causative organism. If every human on earth from now on was vaccinated with the tetanus toxoid (easier said than done), we would eliminate tetanus as a disease without having exterminated Clostridium tetani. It is conceivable, in general, to strive for elimination of a disease without having to eliminate the organism.” Alphagene
The aim of most efforts to control infectious diseases is to eliminate the disease, not eradicate the infectious organism. To distinguish between the two aims, the CDC and WHO generally use “eliminate” when speaking about controlling disease and “eradicate” in those rare instances where the aim is to eradicate the infectious organism. The following quote from a CDC publication illustrates the distinction: “Parasitic Diseases — Dracunculiasis (guinea-worm disease) eradication is in progress. Although no additional parasitic diseases were considered to be current candidates for eradication, the increasing availability of potent, long-acting drugs brings extraordinary opportunities for overcoming onchocerciasis and lymphatic filariasis, and the effectiveness of the strategy for controlling the triatomid vectors provides similar opportunities for American trypanosomiasis (Chagas disease). The workgroup concluded that onchocerciasis (river blindness) and lymphatic filariasis (caused by all Wuchereria and most Brugia infections) could be eliminated and possibly eradicated in the future. For the 5% of cases of lymphatic filariasis caused by Brugia malayi, which also has an animal reservoir (in South-east Asia), elimination of disease, but not infection, is feasible. Similarly, for Chagas disease where animal reservoirs exist, elimination of disease, but not infection, is feasible.”
OK! OK! I’ll buy the latest copy of Control of Communicable Diseases in Man! I was going to wait for the movie, but I guess I’ll go ahead and get the book now.
But if I find one pig with guinea worm you are soooo gonna hear about it…
Okay, so I keep my older version of CCDM at home and my newer version is at work. So sue me.
Jill
No wait. I take back that last sentence!
(ps - there is a joke website “Save the Guinea Worm”)