page_title: Dracunculus medinensis
section_title: Lifecycle
hierarchical_section_title: Dracunculus medinensis / Lifecycle
caption_attribution_description: Diagram of the life cycle of Dracunculus medinensis
context_page_description: Dracunculus medinensis or Guinea worm is a nematode that causes dracunculiasis, also known as guinea worm disease. The disease is caused by the female which, at up to 80 centimetres in length, is among the longest nematodes infecting humans. In contrast, the longest recorded male Guinea worm is only 4 cm.
  The common name "guinea worm" is derived from the Guinea region of Western Africa.
context_section_description: D. medinensis larvae are found in fresh water, where they are ingested by copepods (small crustaceans) of the genus Cyclops. Within the copepod, the D. medinensis larvae develop to an infective stage within 14 days. When the infected copepod is ingested by a mammalian host, by drinking unfiltered water the copepod is then dissolved by stomach acid and dies and the D. medinensis larvae are released and migrate through the wall of the mammalian intestine, and enter the abdominal cavity and retro-peritoneal space where they mature into adults. After maturation into adults and copulation (sexual intercourse) occurs, the males die and females (length 70-120 cm) migrate in subcutaneous tissue towards the skins surface. Around a year after the infection, the female causes the formation of a blister on the skin's surface, generally on the lower extremities, though occasionally on the hand or scrotum. When the blister ruptures, the female slowly emerges over the course of several days or weeks. This causes extreme pain and irritation to the host. During those few days to hours before the worm exits the skin, the person may develop a fever, pain, or swelling in that area. When the host submerges the affected body part in water, the female expels thousands of larvae into the water. From here, the larvae infect copepods, continuing the life cycle. After the worm exits the skin the wound caused by the emerging worm often develops a secondary bacterial infection. Permanent damage can occur if infection goes untreated around a joint and causes the joint to lock. Most cases occur in areas without access to health care facilities. (https://www.cdc.gov/parasites/guineaworm/gen_info/faqs.html)
caption: General lifecycle of D. medinensis in humans
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