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Dracunculiasis, also called guinea worm disease (GWD), is an infection by the guinea worm. 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 the lower limb.〔 The worm then comes out of 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. Humans and dogs are the only known animals that guinea worms infect.〔〔 The worm is about one to two millimeters wide and an adult female is 60 to 100 centimeters long (males are much shorter at ).〔〔 Outside of humans the eggs 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 the disease must occur each year in humans to stay in an area. A diagnosis of the disease can usually be made based on the signs and symptoms of the disease. 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. 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.〔 In 2014 there were 126 cases of the disease reported. This is down from 3.5 million cases in 1986.〔 It only exists in 4 countries in Africa, down from 20 countries in the 1980s.〔〔 The country most affected is South Sudan.〔 It will likely be the first parasitic disease to be globally eradicated. Guinea worm disease has been known since ancient times.〔 It is mentioned in the Egyptian medical Ebers Papyrus, dating from 1550 BC.〔 The name dracunculiasis is derived from the Latin "affliction with little dragons", while the name "guinea worm" appeared after Europeans saw the disease on the Guinea coast of West Africa in the 17th century. A species similar to guinea worms causes disease in other animals.〔 These do not appear to infect humans. It is classified as a neglected tropical disease. ==Signs and symptoms== Dracunculiasis is diagnosed by seeing the worms emerging from the lesions on the legs of infected individuals and by microscopic examinations of the larvae. As the worm moves downwards, usually to the lower leg, through the subcutaneous tissues, it leads to intense pain localized to its path of travel. The painful, burning sensation experienced by infected people has led to the disease being called "the fiery serpent". Other symptoms include fever, nausea, and vomiting.〔 Female worms cause allergic reactions during blister formation as they migrate to the skin, causing an intense burning pain. Such allergic reactions produce rashes, nausea, diarrhea, dizziness, and localized edema. When the blister bursts, allergic reactions subside, but skin ulcers form, through which the worm can protrude. Only when the worm is removed is healing complete. Death of adult worms in joints can lead to arthritis and paralysis in the spinal cord. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dracunculiasis」の詳細全文を読む スポンサード リンク
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