Elephantiasis

Elephantiasis is a disease that is characterized by the thickening of the skin and underlying tissues, especially in the legs and genitals. In some cases, the disease can cause certain body parts, such as the scrotum, to swell to the size of a softball or basketball. ("Elephantitis" is a common mis-hearing or mis-remembering of the term, from confusing the ending -iasis -- process or resulting condition -- with the more commonly heard -itis -- irritation or inflammation.) Its proper medical name is lymphatic filariasis.

Causes

Elephantiasis is often caused by microscopic, thread-like parasitic worms such as Wuchereria bancrofti, Brugia malayi, and B. timori, all of which are transmitted by Mosquitoes. Consequently, it is common in tropical regions and Africa. Obstruction of the lymphatic vessels leads to swelling in the lower torso, typically in the legs and genitals. It is not definitively known if this swelling is caused by the parasite itself, or by the immune system's response to the parasite.

Alternatively, elephantiasis may occur in the absence of parasitic infection. This nonparasitic form of elephantiasis, known as nonfilarial elephantiasis or podoconiosis, and areas of high prevalence have been documented in Uganda, Tanzania, Kenya, Rwanda, Burundi, Sudan and Ethiopia. The worst affected area is Ethiopia, where up to 6% of the population is affected in endemic areas. 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.

The adult worms only live in the human lymph system.

Cultural aspects

Elephantiasis is associated in the public mind with "The Elephant Man", the carnival stage name of Joseph Merrick. The name refers to the resemblance of the sufferer's limbs to the thick, baggy skin on the limbs and trunks of elephants. However, it is now believed that Merrick's deformity was not actually caused by elephantiasis, but by a completely different medical problem called Proteus Syndrome.

Treatment

("Bellevue Venus" Oscar G. Mason's portrait of a woman with elephantiasis, published in Fox.)

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

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.

Also, 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.

Antibiotics as a possible treatment

In 2003 it was suggested that the common antibiotic doxycycline might be effective in treating elephantiasis. 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 in June 2005 by the Liverpool School of Tropical Medicine reported that an 8 week course almost completely eliminated microfilariaemia.

Genome deciphered

On September 20, 2007, scientists mapped the genome or genetic content of Brugia malayi - the roundworm which cause elephantiasis (lymphatic filariasis). Figuring out the content of the genes might lead to development of new drugs and vaccines.

Successful Treatment, Possible Elimination

According to medical experts the worldwide efforts to eliminate this disease is on track to potentially be successful by 2020. 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.

Impact on endemic communities

Elephantiasis caused by lymphatic filariasis is one of the most common causes of disability in the world. 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.