Dracunculiasis

Dracunculiasis
Classification and external resources
A method used to extract a guinea worm from the leg of a human
ICD-10	B72
ICD-9	125.7
DiseasesDB	3945
eMedicine	ped/616
MeSH	D004320

Dracunculiasis ( /drəˌkʌŋkjəˈlaɪ.əsɪs/), also called guinea worm disease (GWD), is a parasitic infection caused by Dracunculus medinensis, a long and very thin nematode (roundworm).^[1] The infection begins when a person drinks stagnant water contaminated with copepods infested by the larvae of the guinea worm. Approximately one year later, the disease presents with a painful, burning sensation as the worm forms a blister, usually on the lower limb. Once prevalent in 20 nations in Asia and Africa, the disease remains endemic in only three countries in Africa.^[2]

The guinea worm is one of the best historically documented human parasites, with tales of its behaviour reaching as far back as the 2nd century BC in accounts penned by Greek chroniclers.^[3] It is also mentioned in the Egyptian medical Ebers Papyrus, dating from 1550 BC.^[4] The name dracunculiasis is derived from the Latin "affliction with little dragons"^[5] while the common name "guinea worm" appeared after Europeans saw the disease on the Guinea coast of West Africa in the 17th century.^[6]

The Carter Center has predicted that guinea worm disease "will be the first parasitic disease to be eradicated and the first disease to be eradicated without the use of vaccines or medical treatment".^[7] The primary mode of prevention is through behaviour change, alongside the provision of clean water sources and the treatment of contaminated drinking water with larvicides. There is no animal or environmental reservoir of D. medinensis and thus the parasite must pass through humans each year to survive.^[7]

Signs and symptoms

Dracunculiasis can migrate to the foot.

As the worm moves downwards, usually to the lower leg, through the subcutaneous tissues it leads to intense pain localized to its path of travel. The painful, burning sensation experienced by infected people has led to the disease being called "the fiery serpent". Other symptoms include: fever, nausea, and vomiting.^[8]

Cause

Guinea worm disease is caused by drinking water contaminated by water fleas (copepods) containing the Dracunculus larvae.^[8]

Life cycle

Life cycle of Dracunculus medinensis

Guinea worm disease used to thrive in some of the world's poorest areas, particularly those with limited or no access to clean water.^[9] In these areas stagnant water sources may still host microscopic arthropods known as copepods, which can carry the larvae of the guinea worm.

The larvae develop for approximately two weeks inside the copepods. At this stage the larvae can cause guinea worm disease if the infected copepods are not filtered from drinking water.^[6] The male guinea worm is typically much smaller (12–29 mm or 0.47–1.1 in) than the female, which, as an adult, can grow to 2–3 feet (0.61–0.91 m) long and be as thick as a spaghetti noodle.^[6][9]

Once inside the body, stomach acid digests the water flea, but not the guinea worm larvae that are sheltered inside. These larvae find their way to the body cavity where the female mates with a male guinea worm. This takes place approximately three months after infection. The male worm dies after mating and is absorbed.^[6]

The female, which contains larvae, burrows into the deeper connective tissues or adjacent to long bones or joints of the extremities.^[6]

Approximately one year after the infection began, the worm creates a blister in the human host's skin—usually on the leg or foot.^[10] Within 72 hours the blister ruptures, exposing one end of the emergent worm. This blister causes a very painful burning sensation as the worm emerges. Infected persons often immerse the affected limb in water to relieve the burning sensation. Once the blister or open sore is submerged in water, the adult female releases hundreds of thousands of guinea worm larvae, contaminating the water supply.

During the next few days, the female worm is capable of releasing more larvae whenever it comes in contact with water as it extends its posterior end through the hole in the host's skin. These larvae contaminate the water supply and are eaten by copepods, thereby repeating the life-cycle of the disease. Infected copepods can live in the water for only two to three weeks if they are not ingested by a person. Infection does not create immunity, so people can repeatedly experience guinea worm disease throughout their lives.^[9]

In drier areas just below the Sahara desert, cases of the disease often emerge during the rainy season, which for many agricultural communities is also the planting or harvesting season. Elsewhere, the emerging worms are more prevalent during the dry season, when ponds and lakes are smaller and copepods, thus, are more concentrated in them. Guinea worm disease outbreaks can cause serious disruption to local food supplies and school attendance .^[9]

Prevention

Sudanese boys using pipe filters to prevent guinea worm disease

Guinea worm disease can be transmitted only by drinking contaminated water, and can be completely prevented through relatively simple measures that could result in the disease being eradicated:^[8]

• Drinking water drawn solely from underground sources free from contamination, such as a borehole or hand-dug wells.
• Filtering drinking water, using a fine-mesh cloth filter like nylon, to remove the guinea worm-containing crustaceans.
• Preventing people with emerging guinea worms from entering ponds and wells used for drinking water.
• Developing new sources of drinking water that lack the parasites, or repairing dysfunctional ones.

Water sources can also be treated with larvicides to kill worm-carrying crustaceans.^[11]

Treatment

There is no vaccine or medicine to treat or prevent Guinea worm disease.^[8] Once a Guinea worm begins emerging, a person must wrap the live worm around a piece of gauze or a stick to extract it from the body (a long, painful process which usually takes weeks or months).^[7] This is the same treatment that is noted in the famous ancient Egyptian medical text, the Ebers papyrus from 1550 BC^[6] Some people have said that extracting a Guinea worm feels like the afflicted area is on fire.^[12][13] However, if the infection is identified before an ulcer forms, the worm can also be surgically removed by a trained doctor in a medical facility.^[9]

Although Guinea worm disease is usually not fatal, the wound where the worm emerges could develop a secondary bacterial infection such as tetanus, which may be life-threatening—a concern in endemic areas where there is typically limited or no access to health care.^[14] Analgesics can be used to help reduce swelling and pain and antibiotic ointments can help prevent secondary infections at the wound site.^[9]

Use of metronidazole or thiabendazole may make extraction easier, but also may lead to migration to other parts of the body.^[15]

Epidemiology

In 1986, there were an estimated 3.5 million cases of Guinea worm in 20 endemic nations in Asia and Africa.^[7] The number of cases has been reduced by more than 99% to 3,190 in 2009, 3,185 of them in the four remaining endemic nations of Africa: Sudan, Ghana, Mali and Ethiopia. This is the lowest number of cases since the eradication campaign began. As of 2010, however, the WHO predicted it will be "a few years yet" before eradication is achieved, on the basis that it took 6–12 years for the countries that have so far eliminated Guinea worm transmission to do so after reporting a similar number of cases to that reported by Sudan in 2009.^[16] The total for 2010 was 1,797 cases.^[17] All four remaining endemic countries succeeded in reducing their case totals further during this period, with Ghana in particular achieving a 97% reduction from 242 cases in 2009 to 8 cases in 2010, all of them contained. However, Chad unfortunately reported its first cases since 1998, with ten cases reported from 7 villages in 5 districts. The source of these cases is not yet clear.^[18]

The World Health Organization is the international body that certifies whether a disease has been eliminated from a country or eradicated from the world.^[19] The Carter Center also reports the status of the Guinea worm eradication program by country.^[20]

Certified free

Endemic countries must report to the International Commission for the Certification of Dracunculiasis Eradication and document the absence of indigenous cases of Guinea worm disease for at least three consecutive years to be certified as Guinea worm-free by the World Health Organization.^[21]

The results of this certification scheme have been remarkable: by 2007, Benin, Burkina Faso, Chad, Côte d'Ivoire, Kenya, Mauritania, Togo, and Uganda had stopped transmission, and Cameroon, CAR, India, Pakistan, Senegal, Yemen were WHO certified.^[20]

Endemic

At the end of 2010, Sudan, Mali and Ethiopia still had endemic transmission, Ghana appeared to have just succeeded in eliminating domestic transmission, and low-level transmission had just been discovered in Chad, although it has not yet been ascertained whether this was from hidden ongoing transmission or a new importation. The major focus is southern Sudan, which reported 94% of all cases in 2010.^[18][22]

Country	Location	2007	2008	2009	2010	Description
South Sudan		5,815[23]	3,618[23]	2,733[16]	1,698[22]	Sudan greatly ratcheted up its eradication effort from 2005 when the Comprehensive Peace Agreement was signed, ending a more than two-decade long civil war. 2006 saw an increase to 15,539 cases of Guinea Worm disease, from 5,569 cases in 2005, as a result of reporting from endemic areas that were no longer war-torn. The Southern Sudan Guinea Worm Eradication Program (SSGWEP) has deployed over 28,000 village volunteers, supervisors and other health staff to work on the program full time. The SSGWEP was able to slash the number of cases reported in 2006 by 63% to 5,815 cases in 2007. Northern Sudan had reported no endemic cases of dracunculiasis since 2001 at the time that South Sudan became independent.[24]
Mali		313[23]	417[23]	186[16]	57[22]	Four of Mali's regions—(Kayes, Koulikoro, Ségou, and Sikasso)—have eliminated dracunculiasis, while the disease is still endemic in the country's other four regions (Gao, Kidal, Mopti, and Timbuktu). Late detection of two outbreaks, due to inadequate surveillance, in 2007 resulted in a meager 36% containment rate in Mali in 2007.[24] 2008 and 2009 were more successful, however, with containment rates of 85% and 73% respectively.[25]
Ethiopia		0[23]	41[23]	24[16]	21[22]	Prior to March 2008, there had been no cases reported in Ethiopia since June 2006.[26]
Chad		0[18]	0[18]	0[18]	10[22]	Prior to 2010, Chad had not reported any indigenous cases of guinea worm in over 10 years.[18]
Ghana		3,358[23]	501[23]	242[16]	8[22]	In Ghana, after a decade of frustration and stagnation, in 2006 a decisive turnaround was achieved. Multiple changes can be attributed to the improved containment and lower incidence of dracunculiasis: better supervision and accountability, active oversight of patients daily by paid staff, and an intensified public awareness campaign. After Jimmy Carter's visit to Ghana in August 2006, the government of Ghana declared Guinea worm disease to be a public health emergency. The overall rate of contained cases has increased in Ghana from 60% in 2005, to 75% in 2006, 84% in 2007, 85% in 2008, 93% in 2009, and 100% in 2010.[18][24][25]

2011

Ghana appears to have eradicated guinea worm with their public health officials reporting in August 2011 that the country has been free of reported cases for over 14 months.^[27] While promising given the incubation period it will be some time before the WHO certifies Ghana as free of this disease.

To the end of June 2011 the number of cases were: Chad 2 cases; Ethiopia 6 cases; Mali 3 cases: and South Sudan 806 cases. After the separation of South Sudan from Northern Sudan, the territory of Northern Sudan has been free of guinea worm disease for several years and it has been certified free of this disease by the WHO.

To the end of August 2011 the number of cases reported were: Chad 7 cases; Ethiopia 8 cases; Mali 9 cases: and South Sudan 944 cases. These occurred in a total of 440 villages. One possible case has been reported from India: investigation into this is ongoing. India has been certified free since 2000 and it is suspected that this possible case may be an imported one. The majority of cases (78%) in South Sudan were located in adjacent two counties of the Eastern Equatoria state: Kapoeta East County (561 cases) and Kapoeta North County (146 cases). Aside from 2 cases imported from South Sudan, no cases were reported in Ethiopia in July and August from the single focus (Gog District) from which all cases in the last few years have been found. Although it is now possible that transmission in Ethiopia has been interrupted official confirmation will not be forthcoming for several months.^[28]

Up to September 2011 the number of uncontained cases were: South Sudan - 241; Chad - 6; Mali - 6; Ethiopia - 1. Of the 70 counties in South Sudan, 56 (80%) are considered free of dracunculiasis.

History of the eradication programme

The global campaign to eradicate Guinea worm disease began at the U.S. Centers for Disease Control and Prevention (CDC) in 1980. In 1986, former U.S. President Jimmy Carter and his not-for-profit organization, The Carter Center, began leading the global campaign, in conjunction with CDC, UNICEF, and WHO.^[29] At this time India, Pakistan, Yemen and 17 countries in Africa were endemic for this disease and reported a total of 3.5 million cases per year.

Carter made a personal visit to a Guinea worm endemic village in 1988. He said: "Encountering those victims first-hand, particularly the teenagers and small children, propelled me and Rosalynn to step up the Carter Center's efforts to eradicate Guinea worm disease."^[30]

President Carter also recruited two African former heads of state to the battle against Guinea worm disease. Then-former head of state of Mali, General Amadou Toumani Toure (since elected President of Mali) has been a strong advocate of Guinea worm eradication in Mali and all other French-speaking African endemic countries since 1992.^[31][32] Since 1999, former Nigerian head of state General (Dr.) Yakubu Gowan has played a similar role in Nigeria, which at the eradication campaign's start had more cases than any other country.^[33]

Since humans are the only host for Guinea worm, the disease can be controlled by identifying all cases and modifying human behavior to prevent it from recurring.^[7] Once all human cases are eliminated, the disease cycle will be broken, resulting in its eradication.^[7]

In 1991, the World Health Assembly (WHA) agreed that Guinea worm disease should be eradicated.^[14] At this time there were 400,000 cases reported each year. The Carter Center has continued to lead the eradication efforts, primarily through its Guinea Worm Eradication Program.^[34] Other major actors in the eradication of Guinea worm disease include: World Health Organization, U.S. Centers for Disease Control and Prevention, Bill & Melinda Gates Foundation, and UNICEF,^[34][35] but the global coalition now includes dozens of other donors, nongovernmental organizations, and institutions, most especially the ministries of health of the affected countries themselves.

In December 2008, The Carter Center announced new financial support totaling US$55 million from the Bill & Melinda Gates Foundation and the United Kingdom Department for International Development.^[36] The funds will help address the higher cost of identifying and reporting the last cases of Guinea worm disease. According to The Carter Center, surveillance of countries, including the smallest communities in the most remote areas, needs to be intensified to prevent outbreaks and setbacks. In the case of Guinea worm disease, which has a one-year incubation period, there is a very high cost of maintaining a broad and sensitive monitoring system and providing a rapid response when necessary.^[36]

Barriers

The eradication of Guinea worm disease has faced several challenges:

• Inadequate security in some endemic countries
• Lack of political will from the leaders of some of the countries in which the disease is endemic
• The need for change in behavior in the absence of a magic bullet treatment like a vaccine or medication
• Inadequate funding at certain times^[5]

One of the most significant challenges facing Guinea worm eradication has been the civil war in southern Sudan, which was largely inaccessible to health workers due to violence.^[5][37] To address some of the humanitarian needs in southern Sudan, in 1995, the longest ceasefire in the history of the war was achieved through negotiations by Jimmy Carter.^[5][37] Commonly called the "Guinea worm cease-fire," both warring parties agreed to halt hostilities for nearly six months to allow public health officials to begin Guinea worm eradication programming, among other interventions.^[37][38]

Public health officials cite the formal end of the war in 2005, as a turning point in Guinea worm eradication because it has allowed health care workers greater access to southern Sudan's endemic areas.^[35] One remaining area in West Africa outside of Ghana remains challenging to ending Guinea worm: northern Mali, where Tuareg rebels have made some affected areas unsafe for health workers.

One of the greater challenges ahead in eradicating dracunculiasis will be confronted in Sudan: there is much uncertainty with future political benchmarks in Sudan (national elections in 2009 and the referendum on the status of southern Sudan in 2011). Sporadic insecurity or widespread civil conflict could at any time ignite, thwarting eradication efforts.^[24] The remaining endemic communities in Sudan are remote, poor and devoid of infrastructure, presenting significant hurdles for effective delivery of interventions against disease. Moreover, residents in these communities are nomadic, moving seasonally with cattle in pursuit of water and pasture, making it very difficult to know where and when transmission occurred. The peak transmission season coincides with the rainy season, hampering travel by public health workers.^[39]

Society and culture

The pain caused by the worm's emergence—which typically occurs during planting and harvesting seasons—prevents many people from working or attending school for as long as three months. In heavily burdened agricultural villages fewer people are able to tend their fields or livestock, resulting in food shortages and lower earnings.^[7][35] A study in southeastern Nigeria, for example, found that rice farmers in a small area lost US$20 million in just one year due to outbreaks of Guinea worm disease.^[7]

History

Dracunculiasis has been a recognized disease for thousands of years:

• Guinea worm has been found in calcified Egyptian mummies.^[7]
• An Old Testament description of "fiery serpents" may have been referring to Guinea Worm: "And the Lord sent fiery serpents among the people, and they bit the people; and much people of Israel died." (Numbers 21:4–9).^[6]
• The 2nd century BC, Greek writer Agatharchides, described this affliction as being endemic amongst certain nomads in what is now Sudan and along the Red Sea.^[6]
• The traditional (and still current) method of extracting guinea worm by twisting the worm around a stick may have inspired the rod of Asclepius, a symbol of medicine since Ancient Greek times which portrays a snake winding around a staff.^[40]
• The unusually high incidence of dracunculiasis in the city of Medina led to it being included in part of the disease's scientific name "medinensis." A similar high incidence along the Guinea coast of West Africa gave the disease its more commonly used name.^[6] Guinea worm is no longer endemic in either location.

In modern times, the first to describe dracunculiasis and its pathogenesis was the Bulgarian physician Hristo Stambolski, during his exile in Yemen (1877–1878).^[41] His theory was that the cause was infected water which people were drinking.

See also

• Infectious disease in the 20th century
• List of infectious diseases
• List of parasites (human)
• Tropical disease
• Neglected disease
• Waterborne diseases
• Eradication of infectious disease

References

1. ^ James, WD, Berger TG (2006). Andrews' Diseases of the Skin: Clinical Dermatology. Saunders Elsevier. p. 437. ISBN 0-7216-2921-0. 
2. ^ "No more Guinea worm in Ghana!". google.org. http://blog.google.org/2011/08/no-more-guinea-worm-in-ghana.html. 
3. ^ Piper R (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals. Greenwood Press. pp. 189–91. ISBN 978-0313339226. 
4. ^ Palmer and Reeder. "Guinea Worm Infection (Dracunculiasis)". International Society of Radiology. http://www.isradiology.org/tropical_deseases/tmcr/chapter27/intro.htm. 
5. ^ ^{a b c d} Barry M (June 2007). "The tail end of guinea worm — global eradication without a drug or a vaccine". N. Engl. J. Med. 356 (25): 2561–4. doi:10.1056/NEJMp078089. PMID 17582064. http://content.nejm.org/cgi/content/full/356/25/2561. 
6. ^ ^{a b c d e f g h i} Tropical Medicine Central Resource. "Dracunculiasis". Uniformed Services University of the Health Sciences. http://www.isradiology.org/tropical_deseases/tmcr/chapter27/intro.htm. Retrieved 2008-07-15. 
7. ^ ^{a b c d e f g h i} "Guinea Worm Eradication Program". The Carter Center. Carter Center. http://www.cartercenter.org/health/guinea_worm/mini_site/facts.html. Retrieved 2011-03-01. 
8. ^ ^{a b c d} "Dracunculiasis". World Health Organization. http://www.who.int/topics/dracunculiasis/en/. Retrieved 2010-07-12. 
9. ^ ^{a b c d e f} "Fact Sheet:Dracunculiasis — Guinea Worm Disease". CDC. 2008-07-15. http://www.cdc.gov/ncidod/dpd/parasites/dracunculiasis/factsht_dracunculiasis.htm. Retrieved 2010-07-12. 
10. ^ Centers for Disease Control and Prevention (CDC) (August 2007). "Progress toward global eradication of dracunculiasis, January 2005-May 2007". MMWR Morb. Mortal. Wkly. Rep. 56 (32): 813–7. PMID 17703170. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5632a1.htm. 
11. ^ Hopkins, D.; Richards Jr, F.; Ruiz-Tiben, E.; Emerson, P.; Withers Jr, P. (2008). "Dracunculiasis, onchocerciasis, schistosomiasis, and trachoma". Annals of the New York Academy of Sciences 1136: 45–52. Bibcode 2008NYASA1136...45H. doi:10.1196/annals.1425.015. PMID 17954680.  edit
12. ^ "World moves closer to eradicating ancient worm disease". World Health Organization. 2007-03-27. http://www.who.int/mediacentre/news/notes/2007/np15/en/index.html. Retrieved 2008-07-15. 
13. ^ McNeil, DG (2006-03-26). "Dose of Tenacity Wears Down a Horrific Disease". New York Times. http://www.nytimes.com/2006/03/26/international/africa/26worm.html. Retrieved 2008-07-15. 
14. ^ ^{a b} Centers for Disease Control and Prevention (CDC) (December 1993). "Recommendations of the International Task Force for Disease Eradication". MMWR Recomm Rep 42 (RR–16): 1–38. PMID 8145708. http://www.cdc.gov/mmwr/preview/mmwrhtml/00025967.htm. 
15. ^ Dracunculiasis: Treatment & Medication~treatment at eMedicine
16. ^ ^{a b c d e} WHO (7 May 2010). "Dracunculiasis eradication – global surveillance summary, 2009" (PDF). Wkly Epidemiol Rec (World Health Organization) 85 (19): 166–175. http://www.who.int/entity/wer/2010/wer8519.pdf. 
17. ^ Case Totals, Carter Center, accessed Oct 3, 2011
18. ^ ^{a b c d e f g} "Guinea Worm Wrap-Up 202" (PDF). Carter Center. http://www.cartercenter.org/resources/pdfs/news/health_publications/guinea_worm/wrap-up/202.pdf. Retrieved 2011-01-20. 
19. ^ "WHO certifies seven more countries as free of guinea-worm disease". World Health Organization. http://www.who.int/neglected_diseases/guineaworm_press_note/en/index.html. Retrieved 2010-05-14. 
20. ^ ^{a b} "Activities by Country - Guinea Worm Eradication Program". Carter Center. http://www.cartercenter.org/countries/activities_gw.html. Retrieved 2010-03-16. 
21. ^ CDC (2000-10-11). "Progress Toward Global Dracunculiasis Eradication, June 2000". MMWR Morb. Mortal. Wkly. Rep. 49 (14): 731–5. doi:10.1001/jama.284.14.1778. PMID 11041744. http://jama.ama-assn.org/cgi/content/full/284/14/1778. 
22. ^ ^{a b c d e f} WHO (4 March 2011). "Monthly report on dracunculiasis cases, January–December 2010" (PDF). Wkly Epidemiol Rec (World Health Organization) 86 (10): 91–2. PMID 21395188. http://www.who.int/entity/wer/2011/wer8610.pdf. 
23. ^ ^{a b c d e f g h} "Progress toward Global Eradication of Dracunculiasis, January 2008–June 2009". Medscape. http://www.medscape.com/viewarticle/711296. Retrieved 2010-05-02. 
24. ^ ^{a b c d} Hopkins DR, Ruiz-Tiben E, Downs P, Withers PC, Roy S (October 2008). "Dracunculiasis eradication: neglected no longer". Am. J. Trop. Med. Hyg. 79 (4): 474–9. PMID 18840732. http://www.ajtmh.org/cgi/pmidlookup?view=long&pmid=18840732. 
25. ^ ^{a b} "Guinea worm wrap-up 195, 12 March 2010" (PDF). Carter Center. http://cartercenter.org/resources/pdfs/news/health_publications/guinea_worm/wrap-up/195.pdf. Retrieved 2010-03-16. 
26. ^ Centers for Disease Control and Prevention (CDC) (October 2008). "Update: progress toward global eradication of dracunculiasis, January 2007–June 2008". MMWR Morb. Mortal. Wkly. Rep. 57 (43): 1173–6. PMID 18971919. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5743a2.htm. 
27. ^ http://www.voanews.com/english/news/africa/west/Ghana-joins-14-other-African-Nations-in-Eradicating-Guinea-Worm-126700018.html
28. ^ http://cartercenter.org/resources/pdfs/news/health_publications/guinea_worm/wrap-up/207.pdf
29. ^ "International Task Force for Disease Eradication — Original Members (1989–1992)". Carter Center. http://www.cartercenter.org/health/itfde/original_members.html. Retrieved 2008-07-17 
30. ^ Carter, Jimmy; Lodge, Michelle (2008-03-31). "A Village Woman's Legacy" (PDF). TIME. http://www.cartercenter.org/resources/pdfs/news/health_publications/guinea_worm/time_village_womans_legacy_mar31_08.pdf. Retrieved 2008-07-15 
31. ^ Jimmy Carter (2004-05-19). "Remarks of Mr Jimmy Carter, former President of the United States of America, at the World Health Assembly". World Health Organization. http://www.who.int/mediacentre/events/2004/wha57/carter/en/. Retrieved 2008-07-17 
32. ^ "Mali's President Touré, Southern Sudan Program Director Logora Honored With The Jimmy and Rosalynn Carter Award". Carter Center. 2008-04-02. http://www.cartercenter.org/news/pr/toure_honored.html. Retrieved 2008-07-17 
33. ^ "Jimmy Carter and General Dr. Yakubu Gowon Encourage Nigerian Officials to Control Schistosomiasis, Other Diseases". Carter Center. 2008-04-02. http://www.cartercenter.org/news/pr/nigeria_021507.html. Retrieved 2008-07-17 
34. ^ ^{a b} "2006 Gates Award for Global Health: The Carter Center". Carter Center. 2006. http://www.cartercenter.org/news/documents/nondatabase/speech_gates.html. Retrieved 2010-03-08 
35. ^ ^{a b c} Donald R. Hopkins, Ernesto Ruiz-Tiben, Philip Downs, P. Craig Withers, Jr., James H. Maguire (2005-10-01). "Dracunculiasis Eradication: The Final Inch". American Journal of Tropical Medicine and Hygiene 73 (4): 669–675. PMID 16222007. http://www.ajtmh.org/cgi/content/abstract/73/4/669. Retrieved 2008-07-15 
36. ^ ^{a b} "Guinea Worm Cases Hit All-Time Low: Carter Center, WHO, Gates Foundation, and U.K. Government Commit $55 Million Toward Ultimate Eradication Goal". Carter Center. http://www.cartercenter.org/news/pr/gates_120508.html. Retrieved 2008-12-08 
37. ^ ^{a b c} "Sudan". Carter Center. http://www.cartercenter.org/countries/sudan.html. Retrieved 2008-07-15 
38. ^ Hopkins, Donald R.; Withers, P. Craig, Jr. (2002). "Sudan's war and eradication of dracunculiasis". Lancet 360: s21–2. doi:10.1016/S0140-6736(02)11806-X 
39. ^ WHO (2 May 2008). "Dracunculiasis eradication" (PDF). Wkly Epidemiol Rec (World Health Organization) 83 (18): 159–167. PMID 18453066. http://www.who.int/entity/wer/2008/wer8318.pdf. 
40. ^ Keith Blayney (2002). "Caduceus vs Staff of Asclepius". http://www.drblayney.com/Asclepius.html. Retrieved 2009-06-24. 
41. ^ Христо Стамболски: Автобиография, дневници и mспомени. (Autobiography of Hristo Stambolski. Sofia : Dŭržavna pečatnica, 1927–1931)

External links

• "Guinea Worm Disease Eradication Program". Carter Center. http://www.cartercenter.org/health/guinea_worm/index.html. 
• Nicholas D. Kristof from the New York Times follows a young Sudanese boy with a Guinea Worm parasite infection who is quarantined for treatment as part of the Carter programme
• Tropical Medicine Central Resource: "Guinea Worm Infection (Dracunculiasis)"
• World Health Organization on Dracunculiasis