Dracunculus medinesis: The Most Cunning Parasite from an Immunological Perspective By: Tiffany Walsh November 10, 2005

Dracunculus medinensis Phylum: NEMATODA CLASS: SECERNENTEA ORDER: SPIRURIDA FAMILY: DRACUNCULIDAE Dracunculus medinensis Common name: Guinea worm, medina worm, serpent worm

Historical:  Thought to be referred to in a book written in Egypt 3,500 years ago (the Ebers' Papyrus).  Probably the "fiery serpent" referred to in the Bible.  Also may be the coiled serpents on the "Caduceus" the symbol of a physician.

Dracunculus medinensis Hosts: Humans Hosts: Humans Distribution: Asia, Africa, Indonesia, Fiji, Brazil Distribution: Asia, Africa, Indonesia, Fiji, Brazil –Mostly in Sudan as of 2004.

Map-2002

What do they LOOK like?

Life Cycle Adult females in subcutaneous tissues of the legs and arms. Adult females in subcutaneous tissues of the legs and arms. Blister forms over nematode. Breaks when exposed to water. Blister forms over nematode. Breaks when exposed to water. Nematode uterus ruptures and discharges first stage juveniles into the water (ovoviviparous). Nematode uterus ruptures and discharges first stage juveniles into the water (ovoviviparous). Juveniles ingested by copepod (intermediate host, 2 molts within copepod). Juveniles ingested by copepod (intermediate host, 2 molts within copepod). Copepod swallowed by human. Copepod swallowed by human. Juveniles migrate via lymph system. Juveniles migrate via lymph system. Develop to adults in subcutaneous tissues. Develop to adults in subcutaneous tissues.

Symptoms/Pathogenicity None until blister forms and toxic fluids result in - None until blister forms and toxic fluids result in - a rash accompanied by severe itching a rash accompanied by severe itching nausea nausea vomiting vomiting diarrhea diarrhea dizziness. dizziness. Secondary bacterial infections of opening are possible. Secondary bacterial infections of opening are possible. There may be later symptoms--fibrosis of the skin, muscles, tendons and joints ( may interfere with locomotion or use of limbs). There may be later symptoms--fibrosis of the skin, muscles, tendons and joints ( may interfere with locomotion or use of limbs).

Future Management Filter or boil water, or treat with chlorine to kill intermediate host. Filter or boil water, or treat with chlorine to kill intermediate host. Avoid bathing or wading in drinking water. Avoid bathing or wading in drinking water. Remove worms by extraction or with surgery. Remove worms by extraction or with surgery. Drug therapy. Drug therapy. Video Video