Dracunculus medinesis: The Most Cunning Parasite from an

Immunological Perspective

By: Tiffany Walsh

November 10, 2005

Dracunculus medinensisDracunculus medinensis

Phylum: NEMATODAPhylum: NEMATODA

CLASS: SECERNENTEACLASS: SECERNENTEA

ORDER: SPIRURIDAORDER: SPIRURIDA

FAMILY: DRACUNCULIDAEFAMILY: DRACUNCULIDAEDracunculus medinensisDracunculus medinensis

Common name: Guinea worm, Common name: Guinea worm, medina worm, serpent wormmedina worm, serpent worm

Historical:Historical:

Thought to be referred to in a Thought to be referred to in a book written in Egypt 3,500 book written in Egypt 3,500 years ago (the Ebers' years ago (the Ebers' Papyrus). Papyrus).

Probably the "fiery serpent" Probably the "fiery serpent" referred to in the Bible. referred to in the Bible.

Also may be the coiled Also may be the coiled serpents on the "Caduceus" serpents on the "Caduceus" the symbol of a physician. the symbol of a physician.

Dracunculus medinensisDracunculus medinensis

Hosts: HumansHosts: Humans

Distribution: Distribution: Asia, Africa, Indonesia, Asia, Africa, Indonesia, Fiji, BrazilFiji, Brazil– Mostly in Sudan as of 2004.Mostly in Sudan as of 2004.

Map-2002Map-2002

What do they LOOK like?What do they LOOK like?

Life Cycle Life Cycle Adult females in subcutaneous tissues of the legs Adult females in subcutaneous tissues of the legs

and arms. and arms. Blister forms over nematode. Breaks when Blister forms over nematode. Breaks when

exposed to water. exposed to water. Nematode uterus ruptures and discharges first Nematode uterus ruptures and discharges first

stage juveniles into the water (ovoviviparous). stage juveniles into the water (ovoviviparous). Juveniles ingested by copepod (intermediate host, Juveniles ingested by copepod (intermediate host,

2 molts within copepod). 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.

http://www.cmaj.ca/content/vol170/issue4/images/large/29ff1.jpeg

Symptoms/Pathogenicity Symptoms/Pathogenicity None until blister forms and toxic fluids None until blister forms and toxic fluids

result in - 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 Secondary bacterial infections of opening are possible. are possible.

There may be later symptoms--fibrosis of There may be later symptoms--fibrosis of the skin, muscles, tendons and joints ( may the skin, muscles, tendons and joints ( may interfere with locomotion or use of limbs). interfere with locomotion or use of limbs).

Future ManagementFuture Management

• Filter or boil water, or treat with Filter or boil water, or treat with chlorine to kill intermediate host. chlorine to kill intermediate host.

• Avoid bathing or wading in drinking Avoid bathing or wading in drinking water. water.

• Remove worms by extraction or with Remove worms by extraction or with surgery. surgery.

• Drug therapy. Drug therapy.

• VideoVideo