|Description:||This photograph depicts a Nigerian man having a Guinea worm, Dracunculus medinensis, extracted from his right lower leg. The roundworm has emerged from its subcutaneous burrow just distal to the popliteal fossa, or posterior knee region. The worm has migrated, over a period of approximately one year, to its site of emergence to release its eggs in a local pond or stream. Before the worm emerges, a blister develops on the skin, causing a very painful burning sensation before rupturing within 24 - 72 hours. Once the white, spaghetti-like worm emerges from the wound, it is pulled out only a few centimeters each day, and wrapped around a small stick or piece of gauze. Sometimes a worm can be pulled out completely within a few days, but this painful process often takes weeks.|
Adult female Dracunculus worms emerge from the skin of infected persons annually. Persons with worms protruding through the skin may enter sources of drinking water, unwittingly allowing the worm to release larvae into the water. These larvae are ingested by fresh water copepods (water fleas), where, developing in 10 - 14 days into their infective stage. Persons are infected by drinking water containing the water fleas harboring the infective larvae. Once inside the body, the stomach acid digests the water fleas, but not the larval worms, which find their way to the small intestine, where they penetrate the wall of the intestine and pass into the body cavity. During the next 10 - 14mo, the Guinea worms mature to a full sized adult 60cm to 100cm (2 - 3ft) long, and as wide as a cooked spaghetti noodle. Adult worms mate inside the abdomen, whereupon, the male dies, while the female worm migrates to the site where she will emerge, usually from the lower limbs.