Dracunculus medinensis The Guinea Worm

1. Dracunculus medinensisThe Guinea Worm Brittney Keel

2. Review Scientific name - Dracunculus medinensis Common name - Guinea worm, medina worm, serpent worm One of the largest nematodes, males are approximately 40 mm long and females are 80 cm long It is transmitted from the intermediate host the Copepod to the definitive host the Human.

3. Historical Accounts • The guinea worm, Dracunculus medinensis, has been known from very ancient times. • Egyptian mythology pertaining to the Serpent of Isis has been postulated as relating to dracunculiasis. The "plague of the fiery serpents" which decimated the Hebrews during the Exodus from Egypt, as described in the Book of Numbers. • Early Greek and Roman physicians associated the disease with certain watering holes and wells. Arab and Persian writers of the Middle Ages described the disease and a Persian doctor of the 10th century identified a worm as its cause. • This nematode was known as a parasite of humans about 1530 B.C. Some investigators suggest that the Guinea worm is the "fiery serpent" referred to in the Bible. The symbol of a Physician is the "Caduceus". This is the staff of Hermes and contains coiled serpents on a staff. The serpents are believed to represent the Guinea worm.

4. Discovery • The Ebers papyrus, dating from 1550 B.C., described the disease and its primitive treatment, still used in most endemic areas today. A calcified guinea worm was discovered in the abdominal cavity of an adolescent Egyptian mummy. • Scientists studied Dracunculiasis, but did not discover the full life cycle. • D. medinensis complete life cycle was discovered by Alekei Pavlovitch Fedchenko in 1870. • Indian bacteriologist, Dyneshvar Atmaran Turkhud, solidified Fedchenkos knowledge in 1913 Persian physicians removing the Dracunculus medinensis parasite from the leg of a patient

5. Cultural Practices • People in endemic areas such as Africa, Sudan, and India contribute to the transmission of the disease by placing there infected limb/limbs in water to relieve the pain that the worm causes, and then drinking the contaminated water.

6. Distribution & Prevalence • The Guinea worm is found mostly in Africa, but is also found in India, Pakistan, Saudi Arabia, and Yemen. • Infects approximately 10 million people per year.  The majority of human infections occur in parts of West Africa, East Africa, and India.

7. Prevention & Treatment • To stop the infection of the Guinea worm you must keep Guinea worm larvae out of the drinking water. Use only water that has been filtered or obtained from a safe source. • Water can be boiled, filtered through tightly woven nylon cloth, or treated with a larvae-killing chemical. People with an open Guinea worm wound should not enter ponds or wells used for drinking water. • There is no cure. The only treatment is to remove the worm over many weeks by winding it around a small stick and pulling it out a tiny bit at a time. Sometimes the worm can be pulled out completely within a few days, but the process usually takes weeks or months. • No medication is available to end or prevent infection. However, the worm can be surgically removed before the wound begins to swell. Antihistamines and antibiotics can reduce swelling and ease removal of the worm.

8. References • http://www.stanford.edu/class/humbio103/ParaSites2006/Dracunculiasis/history.html • http://www.who.int/en/ • http://www.astdhpphe.org/infect/guinea.html • http://ucdnema.ucdavis.edu/imagemap/nemmap/Ent156html/nemas/dracunculusmedinensis