When the skin ulcer makes contact with a fresh water source, the female worm extends from the wound to release larvae into the water. The lower limb is the most common site they migrate to in about 90% of all cases. Pregnant adult females, which can grow to one metre in length (but only 1–2mm thick), slowly migrate to the skin surface as they mature over 12 months. Gastric juices kill the crustaceans, releasing the Dracunculus medinensis larvae into the small bowel.ĭracunculus medinensis larvae migrate through the bowel wall into the connective tissue, where the larvae mature and mate 2–3 months later. People become infected after drinking contaminated water, or eating raw or incompletely cooked fish from contaminated water sources. Dracunculus medinensis larvae are ingested by tiny crustaceans (copepods or “water fleas”) present in a water source.
What causes dracunculiasis?ĭracunculiasis is caused by Dracunculus medinensis, a tissue parasite.
In 2019, cases of dracunculiasis were reported in only four countries: Angola, Chad, Cameroon, and South Sudan. The disease was once endemic in twenty countries, with more than three million cases estimated in 1986. Eradication initiatives have seen the annual incidence of dracunculiasis decline substantially since the 1980s. Following eradication from many countries, dracunculiasis is now localised to rural communities in parts of sub-Saharan Africa with inadequate access to clean drinking water.
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