Guinea Worm Disease (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.

Currently, many organizations, including The Global 2000 program of The Carter Center of Emory University, UNICEF, Centers for Disease Control and Prevention (CDC), and the World Health Organization (WHO) are helping the last 5 countries in the world (Sudan, Ghana, Mali, Niger, and Nigeria) to eradicate the disease. Since 1986, when an estimated 3.5 million people were infected annually, the campaign has eliminated much of the disease.

In 2007, only 9,585 cases of GWD were reported. Most of those cases were from Sudan (61%) and Ghana (35%). All affected countries are aiming to eliminate Guinea worm disease as soon as possible.

Approximately 1 year after a person drinks contaminated water, the adult female Guinea worm emerges from the skin of the infected person. 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 microscopic copepods (tiny "water fleas") that live in these water sources. Persons become infected by drinking water containing the water fleas harboring the Guinea worm larvae.

Once ingested, the stomach acid digests the water fleas, but not the Guinea worm larvae. 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 larvae grow into full size adults, 60-100 centimeters (2-3 feet) long and as wide as a cooked spaghetti noodle. These adult female worms then migrate and emerge from the skin anywhere on the body, but usually on 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 ruptures within 24-72 hours. Immersion of the affected limb into water helps relieve the pain but it also triggers the Guinea worm to release a milky white liquid containing millions of immature larvae into the water, thus contaminating the water supply and starting the cycle over again. 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.

Source: MedicineNet.com
http://www.medicinenet.com/guinea_worm_disease/article.htm