Case Study - Guinea Worm: Countdown to Zero

Focused effort on a neglected tropical disease has results

From the Centers of Disease Control MMWR Morbidity and Mortality Weekly Report (October 1, 2010 / Vol. 59 / No. 38), 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 This report updates both published (5–7) and previously unpublished data and updates progress toward global eradication of dracunculiasis since January 2009.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."




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(Photo Credit: The Carter Center)