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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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A parasite that has plagued the human race since antiquity is poised to become the second human disease after smallpox to be eradicated. “We are approaching the demise of the last guinea worm who will ever live on earth,” says former U.S. president Jimmy Carter, whose Carter Center has spearheaded the eradication effort.
Unlike polio's high-profile eradication program, the mission to eliminate guinea worm disease has largely been off the public's radar. Affecting some of the poorest and most remote communities in Africa—97 percent of cases are in South Sudan—guinea worm is a parasitic infection caused by the nematode roundworm Dracunculus medinensis. It is the only disease transmitted solely by drinking water, and humans are its only reservoir, says James Hughes, professor of medicine and public health at Emory University. The disease spreads when villagers consume water containing fleas that harbor guinea worm larvae. The larvae grow to maturity inside the human body and emerge after a year as a fully grown two- to three-foot-long worm that often exits through the leg or foot. It is an excruciatingly painful process, and individuals often immerse the limb in water to cool the burning sensation, which starts the cycle all over again.
Since 1986 groups such as the Carter Center have distributed cloth water filters to villagers and educated residents about how not to spread the infection. They have also selectively used Abate, a larvicide, to control fleas in the drinking water.
So far the efforts have resulted in a 99 percent reduction in infections, says Sharon Roy of the U.S. Centers for Disease Control and Prevention. In 1986 there were 3.5 million cases, as compared with only 1,060 in 2011 and a mere five as of the first few months of 2012.
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24 Comments
Add CommentIsn't the Guinea worm the basis for the medical symbol of snakes twisted on a cross? As I recall, the physicians would be trained in the use of a cross in twisting Guinea worms out without pulling hard enough to break them apart.
Reply | Report Abuse | Link to thisThe medical symbol is based off of the god of medicine Asclepius, who's symbol was the snake wrapped around the staff.
Reply | Report Abuse | Link to thisActually the medical symbol, a staff with two snakes, is based off of the Caduceus of Hermes Psychopompos (soul-sender), because of confusion with Aesclupius' own single-serpented staff. One theory I have heard is that Anesthesiologists used the Caduceus for their symbol since Hermes had the ability to put humans to sleep and it was adopted by other doctors of other fields. Unfortunately, Hermes is also the god that leads the souls of the dead to the Underworld.
Reply | Report Abuse | Link to thisAre you serious?? cuz it's an African problem?? #smh
Reply | Report Abuse | Link to thisInteresting article. Interesting commentary. Two minor errors in the article though. Nematode roundworms is a redundancy - all roundworms are nematodes (even the humble earthworm). Of more importance is the statement "humans are it's only reservoir". This is followed by the statement "The disease spreads when villagers consume water containing fleas that harbor guinea worm larvae." Therefore, the flea, by definition, is the intermediate host in the life cycle of the guinea worm. It follows necessarily that the worm has two "reservoirs".
Reply | Report Abuse | Link to thisEarthworms are annelids, segmented worms, not roundworms. Also, redundancy isn't necessarily an error - it can be made for rhetorical purposes, as it appears to have been done here.
Reply | Report Abuse | Link to this> all roundworms are nematodes (even the humble earthworm).
Reply | Report Abuse | Link to thisFalse.
Earthworms are annelids.
The caduceus is the symbol of business and commerce, not medicine.
Reply | Report Abuse | Link to thisnematode
Reply | Report Abuse | Link to thisIn reply to all. I stand corrected.
Reply | Report Abuse | Link to thisIf this comes up twice, please forgive me. Something went wrong. With regard to nematodes/annelids I stand corrected.
Reply | Report Abuse | Link to thisOh thank you "its_Joby" for turning me onto "the cause".
Reply | Report Abuse | Link to thisWhile I myself cannot be a volunteer preserver, I will be happy to distribute the worm larvae to other preservers. I think the Tea Baggers would be ideally suited for such a job.
It was originally the staff of Hermes as the protector of merchants, gamblers, liars, and thieves.
Reply | Report Abuse | Link to thisThat covers both commerce and doctors. HA!
Actually, in a way, you're both right. It has become associated with medicine, especially in the US, because it was confused with the Rod of Asclepius, the god of healing. Its association with Hermes/Mercury means it symbolizes commerce.
But we're never ones to let facts change what we believe.
Although the first organism to be eliminated the smallpox virus has certainly gone from the wild both specimens and data on its genetic code still exist in the laboraties of the military as it is considered useful as a weapon
Reply | Report Abuse | Link to thisAlthough the first organism to be eliminated the smallpox virus has certainly gone from the wild both specimens and data on its genetic code still exist in the laboraties of the military as it is considered useful as weapon
Reply | Report Abuse | Link to thisThe proper symbol of medicine is a staff with one snake, not two.
Reply | Report Abuse | Link to thisTwo snakes is the symbol of Mercury - the god of thieves.
Your comment was pretty funny, until you had to be an ass and put politics in the last sentence.
Reply | Report Abuse | Link to thisJimmy Carter is a cousin on my mom's side. He is also a buffoon, who couldn't come up with this on his own. He just 'lends' his name to the project.
Reply | Report Abuse | Link to thisI was amazed to see that we have a `SAVE THE GUINEA WORM FOUNDATION'. Are we also going to have a `BRING BACK THE VARIOLA VIRUS FOUNDATION' in the name of maintaining biodiversity (and as an additional benefit,controlling the population explosion)? Or maybe one exists already! I guess it is ok for people to sit and advocate saving of the guinea worm when they are sure that they are not likely to be infected. After all its only the poorest of poor in remote Africa who `serve as the human reservoir' for this menace. It is immaterial that `The larvae grow to maturity inside the human body and emerge after a year as a fully grown two- to three-foot-long worm that often exits through the leg or foot. It is an excruciatingly painful process, and individuals often immerse the limb in water to cool the burning sensation, which starts the cycle all over again.'!!
Reply | Report Abuse | Link to thisI suggest that the persons interested in saving the Guinea worm volunteer their own bodies as reservoirs for the guinea worm. Perhaps the authorities can figure out a way to keep such persons isolated somehow and prevent the scourge from spreading to innocent people.
annelid/nematode: glad to see the differentiation noted.
Reply | Report Abuse | Link to thisMy late father who died in 1992 had as a young man seen
Reply | Report Abuse | Link to thispersons infected with guinea worm in then undivided India. I wonder if the disease still exists in India/Pakistan and if any effort is in progress in these countries to eradicate it
RE: Reservoir
Reply | Report Abuse | Link to thisSorry Papadick, you're also incorrect about the reservoir for GWD infection. While yes, the extrinsic lifecycle of the worm is completed within the water flea, this is not a separate reservoir. 1. the survivability within copepods is ~2-3 weeks following a 7-14 day aqueous phase in which the larvae must be consumed by the copepod. Thus, the copepod is a short-term intermediate host. A natural reservoir must be a host capable of sustaining long-term transmissibility of the disease. As D. medinensis can only undergo the reproduction phase of its lifecycle within a human host, it has no natural reservoirs, thus meeting one of the basic criteria for disease eradication.
It doesn't. GWD exists only in South Sudan, Ethiopia, Chad and Mali. S. Sudan makes up ~90% of extant cases.
Reply | Report Abuse | Link to thisThis is a joke. It's a website that, if I remember the story correctly, was started to vent frustration. A while back there was a meeting where people were questioning possible environmental consequences of GWD eradication. Though this is probably a good question to consider, in the intervening years no one has seen any consequences. D. medinensis is by no means a keystone species, and it is doubtful that it plays an important role in the local food-chain, as it is fairly digestion resistant. Anyhow, somebody at the meeting ran with the notion and created the Save the GW website. And, it's pretty hillarious.
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