Saturday, November 26, 2005

Weird Disease Of The Week - Dracunculiasis

What is dracunculiasis?
Dracunculiasis, more commonly known as Guinea worm disease (GWD), is a preventable infection caused by the parasite Dracunculus medinensis. Infection affects poor communities in remote parts of Africa that do not have safe water to drink.
In 2003, only 32,193 cases of GWD were reported. Most (63%) of those cases were from Sudan where the ongoing civil war makes it impossible to eradicate the disease. All affected countries except Sudan are aiming to eliminate Guinea worm disease as soon as possible.
How does Guinea worm disease spread?
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 and unwittingly allow the worm to release larvae into the water. These larvae are ingested by fresh water copepods ("water fleas") where these develop into the infective stage in 10-14 days. Persons become infected by drinking water containing the water fleas harboring the infective stage larvae of Dracunculus medinensis.
Once inside the body, the stomach acid digests the water flea, but not the Guinea worm. These larvae find their way to the small intestine, where they penetrate the wall of the intestine and pass into the body cavity. During the next 10-14 months, the female Guinea worm grows to a full size adult 60-100 centimeters (2-3 feet) long and as wide as a cooked spaghetti noodle, and migrates to the site where she will emerge, usually the lower limbs.
A blister develops on the skin at the site where the worm will emerge. This blister causes a very painful burning sensation and it will eventually (within 24-72 hours) rupture. For relief, persons will immerse the affected limb into water, or may just walk in to fetch water. When someone with a Guinea worm ulcer enters the water, the adult female releases a milky white liquid containing millions of immature larvae into the water, thus contaminating the water supply. For several days after it has emerged from the ulcer, the female Guinea worm is capable of releasing more larvae whenever it comes in contact with water.

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