The Guinea worm or Dracunculus medinensis to give it its proper name is a truly horrible parasite. The adult female worm is a thread like creature about two to three feet long (60-100 cm).
Cases are rarely seen outside of rural villages in parts of Africa.
A person becomes infected by drinking water from a standing water source, which contains water fleas infected with the larval form of D. medinensis. Stomach acids digest the water fleas but the larvae pass on into the intestine. The developing worms pierce through the intestinal wall into the body cavity and mate. The male worms die after mating and over the next 10 to 14 months, the female matures before moving through the body. They usually migrate to the lower limbs but they can grow elsewhere in the body. The worms cause a painful blister to appear on the surface of the skin. To ease the pain of this blister a sufferer will often bathe the limb in water. In water, the blister will burst and the tip of the worm will emerges to release a milky fluid containing thousands of larvae into the water. Water fleas ingest these larvae and the cycle of infection can start again. The site of the blister ulcerates and can become the infected with secondary bacteria
Guinea worm infections are extremely painful when the worms emerge and people suffering from this condition are often unable to work or attend school. There are no suitable drugs to treat Guinea worm infections although antihistamines will ease the inflammation and antibiotics can treat any secondary infections. Treatment involves the physical removal of the worm from the body.
In a world of great surgical procedures, Guinea worm removal is extremely “low tech”. Water is poured over the blister to encourage the tip of the worm to emerge. A few inches of the worm is then wound round a stick. The stick with the worm still wound round it is bandaged to the limb and left for a day. Each day more of the worm is wound around the stick until the whole worm is removed. Removal may take several weeks or months but cannot be hurried, as there is a danger of the worm breaking of within the body if pulled to quickly. Sometimes worms are removed surgically before they emerge.
So what can be one to prevent Guinea worm infections? Well the provision of a safe protected drinking water source is an ideal solution. The cost of sinking a borehole to provide such a water source may be beyond the reach of many living the poverty-stricken areas where D. medinensis infections still occur. Boiling water before consumption will kill the water fleas and the larvae but fuel for boiling water is often in short supply in such endemic areas.
A water filter has proven to be an excellent means of preventing infection. In keeping with the “low tech” treatment methods, the filter is equally “low tech”. A piece of tightly woven cloth stretched over a simple wooden frame through which water is poured prior to ingestion will trap the water fleas. No water fleas – no Guinea worms. Water fleas can also be killed by adding an appropriate larvicide to the water. Another control measure is education to try to keep infected persons out of the sources of drinking water, so the water fleas are not infected.
The control measures against Guinea worm have proved to be remarkably successful. By 2007, a disease once known over much of India and Africa was found in only five countries in sub-Saharan Africa. Also by 2007, the WHO certified 180 formerly endemic countries as free of the disease. In 1986, 3.5 million people were estimated to have Guinea worm infection, known cases in 2007 totaled 9585. The fight against D. medinensis is one we can win and Guinea worm will soon be nothing more than a mention in old medical textbooks.