Tropical Diesease: What Is Guinea Worm?

Guinea worm is, in fact, a real worm. It is a large nematode (roundworm), Dracunculus medinensis, which is ingested through drinking contaminated water. The condition is known as dracunculiasis or guinea-worm disease. The worm eventually causes a debilitating and painful infection that begins with a blister, normally on the leg. Around the time of its eruption, the person may experience itching, fever, swelling and burning sensations. Infected people often try to relieve the pain by immersing the infected part in water. If it is immersed in open water sources such as ponds and shallow wells the worm emerges and releases thousands of larvae. The larva is ingested by a water flea (cyclops), where it develops and becomes infective in two weeks. When a person drinks the water, the cyclops is dissolved by the acidity of the stomach, and the larva is activated and penetrates the gut wall. After about one year, a blister forms and the mature worm, one metre long, tries to emerge, thus repeating the life-cycle.

At the beginning of the 20th century, guinea-worm disease was widespread in many countries in Africa and Asia. It is estimated that there were about 50 million cases in the 1950s. Due to concentrated efforts by the international community and the endemic countries, the number of cases of guinea-worm disease was reduced to about 16 000 by 2004. Today, guinea-worm disease is prevalent in only 11 countries in Africa including Sudan, Nigeria, Ghana, Mali, Niger and Togo. A small number of cases have also been reported in Benin, Burkina Faso, Côte d'Ivoire, Mauritania and Ethiopia.

Source: WHO


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