Dracunculiasis
A parasitic disease targeted for eradication by 2027.
Dracunculiasis, or Guinea-worm disease, is a parasitic infection caused by the roundworm *Dracunculus medinensis*. It is a disease of extreme poverty, found in areas where clean drinking water is scarce. The infection begins when a person drinks water contaminated with tiny crustaceans called copepods, which carry Guinea-worm larvae. Stomach acid kills the copepods, freeing the larvae, which then burrow through the digestive tract and into the body. About a year later, the adult female worm moves to an exit point—usually the lower leg—and creates a painful blister on the skin. When the blister bursts, the worm slowly emerges over several weeks, causing intense pain and disabling the person for three to ten weeks. If the wound is submerged in water to relieve the pain, the female worm releases larvae into the water, continuing the cycle. There is no medication to treat or prevent the disease. The main treatment involves carefully winding the emerging worm around a small stick or gauze each day, turning it to maintain gentle tension and speed up the worm’s exit. Pulling too hard can break the worm inside the wound, leading to severe pain and swelling. Prevention focuses on filtering drinking water to remove copepods and educating people not to soak infected limbs in water sources, which spreads the larvae.
Descriptions matching dracunculiasis appear in writings from Greco-Roman doctors. In the 19th and early 20th centuries, the disease was widespread across much of Africa and South Asia, infecting up to 48 million people each year. Eradication efforts began in the 1980s, after smallpox was wiped out in 1977. By 1995, nearly every country with the disease had a national eradication program. Cases then dropped sharply: below 100,000 per year in 1997, below 10,000 in 2007, below 1,000 in 2012, below 100 in 2015, and to just 14 cases in 2022 and 6 in 2023. Since 1986, 16 previously affected countries have eliminated the disease, leaving it mostly in three landlocked central African nations: Chad, Ethiopia, and South Sudan. Three other countries—Angola, Mali, and Sudan—have reported no human cases since the end of 2023 and are awaiting certification as free of the disease. Sudan is pre-certified but not yet confirmed. Cameroon has been certified free of internal transmission since 2007, but has seen three cases since 2019 along its border with Chad. *D.
Quick Facts
- Field
- Infectious disease
- Symptoms
- Painful blister that a long white worm crawls out of
- Onset
- One year after exposure
- Causes
- Ingesting Guinea worm–infected copepods, drinking contaminated water
- Prevention
- Preventing those infected from putting the wound in drinking water, treating contaminated water
- Treatment
- Slowly extracting worm, supportive care
- Frequency
- 10–15 cases worldwide per year (2022–2025)
- Deaths
- ~1% of cases
Facts from the source article.
Lore & Background
Dracunculiasis is caused by the Guinea worm, Dracunculus medinensis. Infection occurs when a person drinks water containing copepods that harbor the worm's larvae. Stomach acid digests the copepod, releasing the larva, which penetrates the digestive tract and escapes into the body. About a year later, the adult female worm migrates to an exit site—usually the lower leg—and induces a painful blister. When the blister bursts, the worm emerges slowly over several weeks, causing disabling pain. The female releases larvae when the wound is submerged in water, continuing the life cycle.
There is no medication to treat or prevent dracunculiasis. Treatment involves carefully wrapping the emerging worm around a small stick or gauze to encourage its exit. Too much tension can break the worm, causing severe pain and swelling. Prevention focuses on filtering drinking water to remove copepods and public education to discourage soaking affected limbs in drinking water sources.
Accounts consistent with dracunculiasis appear in documents from Greco-Roman antiquity. In the 19th and early 20th centuries, it was widespread across much of Africa and South Asia, affecting up to 48 million people per year. Eradication efforts began in the 1980s, and cases have dropped dramatically: below 100,000 in 1997, below 10,000 in 2007, below 1,000 in 2012, below 100 in 2015, and to only 10 in 2025.
Reader's Guide
Dracunculiasis is significant as a disease of extreme poverty that has been targeted for global eradication. Since 1986, 16 previously endemic countries have eradicated the disease, leaving it primarily endemic in Chad, Ethiopia, and South Sudan. The World Health Organization set 2027 as the target date for eradication. If successful, dracunculiasis would become the second human disease to be eradicated, after smallpox. The disease also infects dogs, cats, and baboons, though non-human cases are falling due to eradication efforts. Other Dracunculus species cause dracunculiasis in reptiles worldwide and in mammals in the Americas. The eradication program relies on simple interventions: filtering water, public education, and careful wound management. The dramatic decline in cases—from millions annually to just 10 in 2025—demonstrates the effectiveness of these measures.
Did You Know?
- The female Guinea worm can grow over 100 cm (39 in) long.
- The disease is diagnosed by visual examination of the thin white worm emerging from a blister.
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