Elephantiasis

Elephantiasis
Classification and external resources
"Bellevue Venus" Oscar G. Mason's portrait of a woman with elephantiasis.
ICD-10	B74.0 (ILDS B74.01) I89
ICD-9	125.9, 457.1
DiseasesDB	4824
eMedicine	derm/888
MeSH	D004605

Elephantiasis /ˌɛlɨfənˈtaɪ.əsɨs/ EL-i-fən-TY-ə-sis is a disease that is characterized by the thickening of the skin and underlying tissues, especially in the legs and male genitals. In some cases the disease can cause certain body parts, such as the scrotum, to swell to the size of a basketball.^[1] More rarely, it can cause swelling in the vulva.^[2] It is caused by filariasis or podoconiosis.^[3]

Signs and symptoms

Elephantiasis leads to marked swelling of the lower half of the body.

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  Drawn from the collection at the National Museum of Health and Medicine showing the effect of Elephantiasis in a historic context. Anatomical items: Left Leg, Scrotum.

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  Elephantiasis of the legs due to filariasis. Luzon, Philippines.

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  Man with massive scrotal elephantiasis, Tanzania, early 20th century

Causes

Elephantiasis occurs in the presence of microscopic, thread-like parasitic worms such as Wuchereria bancrofti, Brugia malayi, and B. timori, all of which are transmitted by mosquitoes.^[4] However, the disease itself is a result of a complex interplay between several factors: the worm, the symbiotic Wolbachia bacteria within the worm, the host’s immune response, and the numerous opportunistic infections and disorders that arise. Consequently, it is common in tropical regions and Africa. The adult worms only live in the human lymphatic system.^[5] The parasite infects the lymph nodes and blocks the flow of lymph throughout the body; this results in chronic edema, most often noted in the lower torso (typically in the legs and genitals).^[6]

Podoconiosis

Ethiopian farmer affected by podoconiosis

Alternatively, elephantiasis may occur in the absence of parasitic infection. This nonparasitic form of elephantiasis is known as "nonfilarial elephantiasis" or "podoconiosis", and areas of high prevalence have been documented in Uganda, Tanzania, Kenya, Rwanda, Burundi, Sudan, Egypt and Ethiopia.^[7] The worst affected area is Ethiopia, where up to 6% of the population is affected in endemic areas.^[8][9] Nonfilarial elephantiasis is thought to be caused by persistent contact with irritant soils: in particular, red clays rich in alkali metals such as sodium and potassium and associated with volcanic activity.^[10][11]

Prevention

A banner from the Indian state of Kerala which directs people to take Albendazole tablets as a preventive measure against elephantiasis

According to medical experts the worldwide efforts to eliminate lymphatic filariasis is on track to potentially be successful by 2020.^[12] An estimated 6.6 million children have been prevented from being infected, with another estimated 9.5 million in whom the progress of the disease has been stopped.

For podoconiosis, international awareness of the disease will have to rise before elimination is possible. In 2011, podoconiosis was added to the World Health Organization's Neglected Tropical Disease list, which was an important milestone in raising global awareness of the condition.

Treatment

Treatments for lymphatic filariasis differ depending on the geographic location of the endemic area.^[13] In sub-Saharan Africa, albendazole is being used with ivermectin to treat the disease, whereas elsewhere in the world, albendazole is used with diethylcarbamazine.^[13] Geo-targeting treatments is part of a larger strategy to eventually eliminate lymphatic filariasis by 2020.^[13]

Another form of effective treatment involves rigorous cleaning of the affected areas of the body. Several studies have shown that these daily cleaning routines can be an effective way to limit the symptoms of lymphatic filariasis. The efficacy of these treatments suggests that many of the symptoms of elephantiasis are not directly a result of the lymphatic filariasis but rather the effect of secondary skin infections.^{[citation needed]}

In addition, surgical treatment may be helpful for issues related to scrotal elephantiasis and hydrocele. However, surgery is generally ineffective at correcting elephantiasis of the limbs.

A vaccine is not yet available but is likely to be developed in the near future.^{[citation needed]}

Treatment for podoconiosis consists of consistent shoe-wearing (to avoid contact with the irritant soil) and hygiene - daily soaking in water with an antiseptic (such as bleach) added, washing the feet and legs with soap and water, application of ointment, and in some cases, wearing elastic bandages.^[14] Antibiotics are used in cases of infection.

Antibiotics

In 2003 it was suggested that the common antibiotic doxycycline might be effective in treating lymphatic filariasis.^[15] The parasites responsible for elephantiasis have a population of symbiotic bacteria, Wolbachia, that live inside the worm. When the symbiotic bacteria are killed by the antibiotic, the worms themselves also die.

Clinical trials by the Liverpool School of Tropical Medicine in June 2005 reported that an 8 week course almost completely eliminated microfilariaemia.^[16]

Epidemiology

Lymphatic filariasis affects over 120 million people, primarily in Africa and South-East Asia, with about 40 million disfigured and incapacitated by the disease.^[17]

History

Society and culture

Impact on endemic communities

Elephantiasis caused by lymphatic filariasis is one of the most common causes of disability in the world.^[13] In endemic communities, approximately 10 percent of women can be affected with swollen limbs and 50 percent of men can suffer from mutilating genital disease.^[13]

In areas endemic for podoconiosis, prevalence can be 5% or higher.

Research

On September 20, 2007, geneticists mapped the genome or genetic content of Brugia malayi - the roundworm which causes elephantiasis (lymphatic filariasis). Determining the content of the genes might lead to development of new drugs and vaccines.^[19]

See also

• Elephantiasis tropica
• List of cutaneous conditions

References

External links

• Media related to Elephantiasis at Wikimedia Commons
• Podoconiosis blog with video from Gimbie, Ethiopia
• 'End in Sight' for elephantiasis -Retrieved Oct 9 2008
• Antibiotics help combat Elephantiasis
• Elephantiasis photographic documentation
• The Carter Center Lymphatic Filariasis Elimination Program