Progress Toward Global Eradication of Dracunculiasis, January 2009--June 2010

In 1986, the World Health Assembly (WHA) called for the elimination of dracunculiasis (Guinea worm disease), a parasitic infection in humans caused by Dracunculus medinensis (1). At the time, an estimated 3.5 million cases were occurring annually in 20 countries in Africa and Asia, and 120 million persons were at risk for the disease (1,2). Because of slow mobilization in countries with endemic disease, the 1991 WHA goal to eradicate dracunculiasis globally by 1995 was not achieved (3). In 2004, WHA established a new target date of 2009 for global eradication (4); despite considerable progress, that target date also was not met. This report updates both published (5--7) and previously unpublished data and updates progress toward global eradication of dracunculiasis since January 2009. At the end of December 2009, dracunculiasis remained endemic in four countries (Ethiopia, Ghana, Mali, and Sudan). The number of indigenous cases of dracunculiasis worldwide had decreased 31%, from 4,613 in 2008 to 3,185 in 2009. Of the 766 cases that occurred during January--June 2010, a total of 745 (97%) were reported from 380 villages in Sudan. Ghana, Ethiopia, and Mali each are close to interrupting transmission, as indicated by the small and declining number of cases. The current target is to complete eradication in all four countries as quickly as possible. Insecurity (e.g., sporadic violence or civil unrest) in areas of Sudan and Mali where dracunculiasis is endemic poses the greatest threat to the success of the global dracunculiasis eradication program.

Persons become infected with D. medinensis by drinking water from stagnant sources (e.g., ponds) contaminated by copepods (water fleas) that contain Guinea worm larvae. Currently, no effective drug to treat nor vaccine to prevent dracunculiasis is available, and persons who contract D. medinensis infections do not become immune. After a 1-year incubation period, adult female worms 28--47 inches (70--120 centimeters) long migrate under the skin to emerge, usually through the skin of the foot or lower leg. On contact with water, these worms eject larvae that can then be ingested by copepods and infect persons who drink the water. The emerging worm can be removed by rolling it up on a stick a few centimeters each day. Complete removal averages approximately 4 weeks or more. Disabilities caused by dracunculiasis are secondary to bacterial infections that frequently develop in the skin, causing pain and swelling (8,9).

Dracunculiasis can be prevented by 1) educating persons from whom worms are emerging to avoid bathing affected body parts in sources of drinking water, 2) filtering potentially contaminated drinking water through a cloth filter, 3) treating potentially contaminated surface water with a larvicide such as temephos (Abate), and 4) providing safe drinking water from borehole or hand-dug wells (3). Containment* of transmission, achieved through 1) voluntary isolation of each patient to prevent contamination of drinking water sources, 2) provision of first aid, 3) manual extraction of the worm, and 4) application of occlusive bandages, is a complementary component to the four main interventions.

Countries enter the World Health Organization (WHO) precertification stage of eradication approximately 1 year (i.e., one incubation period for D. medinensis) after reporting their last indigenous case. A case of dracunculiasis is defined as occurring in a person exhibiting a skin lesion or lesions with emergence of one or more Guinea worms. Each person is counted only once during a calendar year. An imported case is an infection acquired in a place (another country or village within the same country) other than the community where detected and reported. Seven countries where transmission of dracunculiasis was formerly endemic (Burkina Faso, Chad, Côte d'Ivoire, Kenya, Nigeria, Niger, and Togo) are in the precertification stage of eradication.

In each country affected by dracunculiasis, a national eradication program receives monthly reports of cases from each village that has endemic transmission. Reporting rates are calculated by dividing the number of villages with endemic dracunculiasis that report each month by the total number of villages with endemic disease. All villages where endemic transmission of dracunculiasis is interrupted (i.e., zero cases reported for 12 consecutive months) are kept under active surveillance with searches of households for persons with signs and symptoms suggestive of dracunculiasis. This is done to ensure that detection occurs within 24 hours of worm emergence so that patient management can begin to prevent contamination of water.

WHO certifies a country free from dracunculiasis after it maintains adequate nationwide surveillance for 3 consecutive years and demonstrates that no cases of indigenous dracunculiasis occurred during that period. As of October 2009, WHO had certified 187 countries and territories as free from dracunculiasis (5); 17 African countries, including four with endemic transmission, remained to be certified.

Country Reports

Sudan. Since 2003, all indigenous cases of dracunculiasis in Sudan have been reported from Southern Sudan. The Southern Sudan Guinea Worm Eradication Program (GWEP) reported 2,733 cases of dracunculiasis in 2009, of which 2,134 (78%) were contained (Table 1). For January--June 2010, the Southern Sudan GWEP reported a provisional total of 745 cases (74% contained, versus 72% contained during January--June 2009), a reduction of 37%, compared with the 1,184 cases reported for the same period in 2009 (Table 2). During 2009, a total of 1,011 villages reported one or more cases; during January--June 2010, a total of 380 villages reported one or more cases, of which 141 reported indigenous cases. During January--April 2010, the Southern Sudan Ministry of Water Resources and Irrigation, the United Nations Children's Fund (UNICEF), and other partners completed borehole wells in 43 villages that had endemic dracunculiasis. During January--June 2010, a total of 14 security incidents (e.g., civil disorder, banditry, or other situations involving violence or threat of violence) disrupted Guinea worm program operations in Southern Sudan, compared with 23 such incidents during January--June 2009.

Ghana. Ghana's GWEP reported 242 cases of dracunculiasis from 33 villages for 2009, of which 19 villages reported indigenous cases and the remaining villages reported cases imported from elsewhere in the country. This is a reduction in indigenous cases of 52%, compared with the 501 cases reported for 2008. Of the 242 cases reported for 2009, 93% were contained (Table 1). Ghana reported zero cases for an entire month for the first time in November 2009. For January--June 2010, Ghana reported eight cases, all of which were contained, and zero cases were reported for June, compared with 228 cases reported for January--June 2009, a reduction of 96%. The last known uncontained case in Ghana occurred in July 2009.

Mali. Mali's GWEP reported 186 indigenous cases in 2009, which was a reduction of 55% from the 417 cases reported in 2008. Of the 186 reported cases for 2009, 135 (73%) were contained. Mali reported only one case (which was contained) during January--June 2010, compared with eight cases during January--June 2009, a reduction of 88%.

Ethiopia. Reporting of indigenous cases resumed in 2008, after approximately 20 months with no known indigenous cases, and for 2009, Ethiopia reported 24 indigenous cases, of which 19 (79%) were contained. For January--June 2010, Ethiopia reported 12 indigenous cases (83% contained) in seven villages, compared with 21 indigenous cases in eight villages (76% contained) during January--June 2009, a reduction of 43%. Beginning in January 2010, active surveillance was extended to all 71 known inhabited settlements of Gambella Region's Gog District, which is the only remaining focus of endemic disease in Ethiopia. Much of the remaining transmission appears to be from ponds along walking paths between the main population centers and dispersed farming communities. Inhabitants of all villages where cases were reported in 2009 or 2010 have been receiving health education, and cloth filters have been distributed to more than 93% of those households and pipe filters to at least 62% Unsafe water sources have been treated with larvicide at 89 (77%) of 117 targeted sites, including the seven villages reporting cases in 2010 and ponds along walking paths. Four of the seven villages now have at least one source of safe drinking water.

Niger and Nigeria. Niger and Nigeria (10)reported zero indigenous cases of dracunculiasis during an entire year for the first time in 2009. Neither country reported cases during January--June 2010.

Reported by

DR Hopkins, MD, E Ruiz-Tiben, PhD, The Carter Center, Atlanta, Georgia. ML Eberhard, Div of Parasitic Diseases and Malaria, Center for Global Health; SL Roy, Div of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, CDC.

Editorial Note

Fewer than 3,200 cases of dracunculiasis were reported globally during 2009, the lowest annual total ever, and the number of countries in which the disease remained endemic was reduced from six to four in 2008. Of the remaining endemic countries, Mali and Ethiopia appear to be close to interrupting transmission, although Mali's peak transmission season† (June--November) for 2010 was just beginning and insecurity has been a major concern in Mali's remaining endemic area. Ghana might have interrupted transmission already, but interruption cannot be confirmed until 1 year after the last known case (i.e., mid-2011). The program in Southern Sudan continues to make progress despite several challenges, of which sporadic insecurity is the most important. Obtaining reports about persons purported to have dracunculiasis in areas free of the disease, properly investigating such reports, and promptly notifying local authorities is a challenge for all four countries.

In October 2009, WHO's International Commission for the Certification of Dracunculiasis Eradication certified three more formerly-endemic countries (Benin, Mauritania, and Uganda) as being free of dracunculiasis transmission, bringing the total number of countries certified to 187, including nine formerly endemic countries since 1996. WHA has not established a new target date for eradication. A status report on the eradication program is expected to be submitted to WHA in May 2011.

References

1. World Health Assembly. Resolution WHA 39.21. Elimination of dracunculiasis: resolution of the 39th World Health Assembly. Geneva, Switzerland: World Health Organization; 1986.
2. Watts SJ. Dracunculiasis in Africa: its geographic extent, incidence, and at-risk population. Am J Trop Med Hyg 1987;37:119--25.
3. Ruiz-Tiben E, Hopkins DR. Dracunculiasis (Guinea worm disease) eradication. Adv Parasitol 2006;61:275--309.
4. World Health Assembly. Resolution WHA 57.9. Eradication of dracunculiasis: resolution of the 57th World Health Assembly. Geneva, Switzerland: World Health Organization; 2004. Available at http://www.who.int/gb/ebwha/pdf_files/wha57/a57_r9-en.pdf. Accessed October 9, 2009.
5. World Health Organization. Dracunculiasis eradication: global surveillance summary, 2009. Wkly Epidemiol Rec 2010;85:166--76.
6. World Health Organization. Monthly report on dracunculiasis cases, January 2009--February 2010. Wkly Epidemiol Rec 2010;85:147--8.
7. CDC. Progress toward global eradication of dracunculiasis, January 2008--June 2009. MMWR 2009;58:1123--5.
8. Imtiaz R, Hopkins DR, Ruiz-Tiben E. Permanent disability from dracunculiasis. Lancet 1990;336:630.
9. Ruiz-Tiben E, Hopkins DR. Dracunculiasis. In: Guerrant RL, Walker DH, Weller PF, eds. Tropical infectious diseases: principles, pathogens, and practice. 2nd ed. New York, NY: Elsevier; 2006:1204--7.
10. Miri E, Hopkins DR, Ruiz-Tiben E, et al. 2010. Nigeria's triumph: dracunculiasis eradicated. Am J Trop Med Hyg 2010;83:215--25.

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