Causes and Symptoms (Magill’s Medical Guide, Sixth Edition)
Elephantiasis is characterized by gross enlargement of a body part caused by the accumulation of fluid and connective tissue. It most frequently affects the legs, but may also occur in the arms, breasts, scrotum, vulva, or any other body part. The disease starts with the slight enlargement of one leg or arm (or other body part). The limb increases in size with recurrent attacks of fever. Gradually, the affected part swells, and the swelling, which is soft at first, becomes hard following the growth of connective tissue in the area. In addition, the skin over the swollen area changes so that it becomes coarse and thickened, looking almost like elephant hide. The elephant-like skin, along with the enlarged body parts, gave the disease the name elephantiasis.
Elephantiasis is found worldwide, mostly in the tropics and subtropics. Most cases of elephantiasis are a result of infection with a parasitic worm called Wuchereria bancrofti (W. bancrofti). W. bancrofti belongs to a group of worms called filaria, or roundworms, and infection with a filarial worm is called filariasis. Filariasis caused by W. bancrofti is the most common and widespread type of human filarial infection and is often called Bancroft’s filariasis. Elephantiasis is the advanced, chronic stage of Bancroft’s filariasis, and only a small percentage of persons with Bancroft’s filariasis will develop elephantiasis. During...
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Treatment and Therapy (Magill’s Medical Guide, Sixth Edition)
One way in which doctors can tell whether a person has Bancroft’s filariasis is by taking a sample of peripheral blood between 10 p.m. and 2 a.m. and looking at the blood under a microscope to try to find microfilariae. Sometimes, the ability to find microfilariae is enhanced by filtering the blood to concentrate the possible microfilariae in a smaller volume of liquid. Many persons infected with W. bancrofti have no detectable microfilariae in their blood, so other methods are available. In the absence of microfilariae, a diagnosis can be made on the basis of a history of exposure, symptoms of the disease, positive antibody or skin tests, or the presence of worms in a sample of lymph tissue. It is important to note that occasionally a few other filarial worms and at least one bacteria can also cause elephantiasis; therefore, if symptoms of elephantiasis are observed, it is important to discover the correct cause so that the proper treatment can be given. Since chronic infection occurs after prolonged residence in areas where the disease occurs, patients with acute disease should be removed from those areas. They also should be reassured that elephantiasis is a rare complication that is limited to persons who have had constant exposure to infected mosquitoes for years.
The best way to avoid contracting filariasis when traveling to an affected area is to avoid being bitten by mosquitoes. Insect repellent,...
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Perspective and Prospects (Magill’s Medical Guide, Sixth Edition)
Dramatic symptoms of elephantiasis, especially the enormous swelling of legs or scrotum, were recorded in much of the ancient medical literature of India, Persia, and the Far East. The embryonic form of microfilariae was first discovered and described by a Frenchman in Paris in 1863. The organism was named for O. Wucherer, who also discovered microfilariae in 1866, and Joseph Bancroft, who discovered the adult worm in 1876. Two important facts about W. bancrofti—namely, its development in mosquitoes and the nocturnal periodicity of the microfilariae—were discovered by Patrick Manson between 1877 and 1879. This was the first example of a disease being transmitted by a mosquito, and its discovery earned for Manson the title of founder of tropical medicine. These and most of the other essential facts of the disease were discovered before the end of the nineteenth century. Progress in the epidemiology and control of filariasis came after World War II. In 1947, DEC was shown to kill filariae in animals, and this result was followed by the successful use of DEC in the treatment of humans. The first promising results in the control of Bancroft’s filariasis by mass administration of DEC were reported in 1957 on a small island in the South Pacific. Through subsequent studies, it has become clear that effective control of the infection can be achieved if sufficient dosages of DEC are administered to infected...
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For Further Information: (Magill’s Medical Guide, Sixth Edition)
Beaver, Paul C., and Rodney C. Jung. Animal Agents and Vectors of Human Disease. 5th ed. Philadelphia: Lea & Febiger, 1985. Discusses all major parasitic diseases. Chapter 12, “Filariae,” which describes those diseases caused by filarial worms, contains helpful photographs and diagrams.
Biddle, Wayne. A Field Guide to Germs. 2d ed. New York: Anchor Books, 2002. This comprehensive book is easily accessible to the nonspecialist and includes a discussion of nearly every virus, bacterium, and fungus known to cause human and nonhuman animal disease. The history of the microbe and the treatment of diseases are included.
Frank, Steven A. Immunology and Evolution of Infectious Disease. Princeton, N.J.: Princeton University Press, 2002. Blends research from molecular biology, immunology, pathogen biology, and population dynamics to discuss how and why parasites vary to escape recognition by the immune system, vaccine design, and the control of epidemics.
Joklik, Wolfgang K., et al. Zinsser Microbiology. 20th ed. Norwalk, Conn.: Appleton and Lange, 1997. The information presented in this textbook is thorough, logical, and supplemented by interesting diagrams, photographs, and charts. Contains a thorough description of Bancroft’s filariasis.
Ransford, Oliver. “Bid the Sickness Cease.” London: John Murray, 1983. Discusses the effect of disease on the...
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Elephantiasis (Encyclopedia of Medicine)
The word elephantiasis is a vivid and accurate term for the syndrome it describes: the gross (visible) enlargement of the arms, legs, or genitals to elephantoid size.
True elephantiasis is the result of a parasitic infection caused by three specific kinds of round worms. The long, threadlike worms block the body's lymphatic system network of channels, lymph nodes, and organs that helps maintain proper fluid levels in the body by draining lymph from tissues into the bloodstream. This blockage causes fluids to collect in the tissues, which can lead to great swelling, called "lymphedema." Limbs can swell so enormously that they resemble an elephant's foreleg in size, texture, and color. This is the severely disfiguring and disabling condition of elephantiasis.
There are a few different causes of elephantiasis, but the agents responsible for most of the elephantiasis in the world are filarial worms: white, slender round worms found in most tropical and subtropical places. They are transmitted by particular kinds (species) of mosquitoes, that is, bloodsucking insects. Infection with these worms is called "lymphatic filariasis" and over a long period of time can cause elephantiasis.
Lymphatic filariasis is a disease of underdeveloped regions found in South America,...
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