Guinea worm disease
Dracunculiasis, also known as Guinea worm disease (GWD), is an infection caused by the parasite Dracunculus medinensis.
A person becomes infected when they drink water that contains water fleas infected with guinea worm larvae. Initially there are no symptoms. About one year later, the person develops a painful burning feeling as the female worm forms a blister in the skin, usually on a lower limb. The worm then emerges from the skin over the course of a few weeks. During this time, it may be difficult to walk or work. It is very uncommon for the disease to cause death.
In humans, the only known cause is Dracunculus medinensis.The worm is about one to two millimeters wide, and an adult female is 60 to 100 centimeters long (males are much shorter at 12–29 mm or 0.47–1.14 in). Outside of humans, the young form can survive up to three weeks, during which they must be eaten by water fleas to continue to develop.The larva inside water fleas may survive up to four months.Thus, in order for the disease to remain in an area, it must occur each year in humans. A diagnosis of the disease can usually be made based on the signs and symptoms.
There is no medication or vaccine against the disease. The worm may be slowly removed over a few weeks by rolling it over a stick. The ulcers formed by the emerging worm may get infected by bacteria. Pain may continue for months after the worm has been removed.
The worm can also be surgically removed by a trained doctor in a medical facility before a blister forms.
Prevention is by early diagnosis of the disease followed by keeping the person from putting the wound in drinking water to decrease spread of the parasite. Other efforts include improving access to clean water and otherwise filtering water if it is not clean. Filtering through a cloth is often enough. Contaminated drinking water may be treated with a chemical called temefos to kill the larva.