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 softball or basketball.[1] It is caused by filariasis or podoconiosis.[2]

The proper medical term for the disease is elephantiasis.[3] It is commonly misheard as "Elephantitis", which substitutes for the ending -iasis (meaning process or resulting condition) the more commonly heard -itis (irritation or inflammation), resulting in "Elephantitis" meaning "inflammation of the elephant".

Contents

Signs and symptoms

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

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] 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 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.[6] The worst affected area is Ethiopia, where up to 6% of the population is affected in endemic areas.[7][8] 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.[9][10]

Prevention

According to medical experts the worldwide efforts to eliminate lymphatic filariasis is on track to potentially be successful by 2020.[11] 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. Podoconiosis does not yet appear on the Neglected Tropical Disease lists,and is not part of the work of organizations such as the World Health Organization.

Treatment

Treatments for lymphatic filariasis differ depending on the geographic location of the endemic area.[12] In sub-Saharan Africa, albendazole is being used with ivermectin to treat the disease, whereas elsewhere in the world, albendazole is used with diethylcarbamazine.[12] Geo-targeting treatments is part of a larger strategy to eventually eliminate lymphatic filariasis by 2020.[12]

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.

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.

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. 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.[13] 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.[14]

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.[15]

History

Many people in Malabar, Nayars as well as Brahmans and their wives — in fact about a quarter or a fifth of the total population, including the people of the lowest castes — have very large legs, swollen to a great size; and they die of this, and it is an ugly thing to see. They say that this is due to the water through which they go, because the country is marshy. This is called pericaes in the native language, and all the swelling is the same from the knees downward, and they have no pain, nor do they take any notice of this infirmity.

—-Tomé Pires, Suma Oriental, 1512–1515.[16]

Society and culture

Impact on endemic communities

Elephantiasis caused by lymphatic filariasis is one of the most common causes of disability in the world.[12] 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.[12]

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). Figuring out the content of the genes might lead to development of new drugs and vaccines.[17]

See also

References

  1. ^ McNeil, Donald (2006-04-09). "Beyond Swollen Limbs, a Disease's Hidden Agony". New York Times. http://www.nytimes.com/2006/04/09/world/americas/09lymph.html. Retrieved 2008-07-17. 
  2. ^ Davey, Gail (2008). "Podoconiosis: let Ethiopia lead the way". The Ethiopian Journal of Health Development 22 (1): 1–2. http://ejhd.uib.no/ejhd-v22-n1/1%20Podoconiosis%20let%20Ethiopia%20lead%20the%20way.pdf. 
  3. ^ http://www.who.int/mediacentre/factsheets/fs102/en/ Retrieved on May 17, 2009
  4. ^ CDC. (2008). "Lymphatic Filariasis". Centers for Disease Control and Prevention.: http://www.cdc.gov/ncidod/dpd/parasites/lymphaticfilariasis/index.htm. 
  5. ^ Niwa, Seiji. "Prevalence of Vizcarrondo worms in early onset lymphatic filariasis: A case study in testicular elephantiasis". Univ Puerto Rico Med J 22: 187–193. 
  6. ^ Davey, Gail; Tekola, Fasil; Newport, Melanie J. (2007). "Podoconiosis: Non-infectious geochemical elephantiasis". Transactions of the Royal Society of Tropical Medicine and Hygiene 101 (12): 1175–80. doi:10.1016/j.trstmh.2007.08.013. PMID 17976670. 
  7. ^ Birrie, H; Balcha, F; Jemaneh, L (1997). "Elephantiasis in Pawe settlement area: Podoconiosis or bancroftian filariasis?". Ethiopian medical journal 35 (4): 245–50. PMID 10214438. 
  8. ^ Destas, K; Ashine, M; Davey, G (2003). "Prevalence of podoconiosis (endemic non-filarial elephantiasis) in Wolaitta, Southern Ethiopia". Tropical doctor 33 (4): 217–20. PMID 14620426. 
  9. ^ Price, EW (1974). "The relationship between endemic elephantiasis of the lower legs and the local soils and climate". Tropical and geographical medicine 26 (3): 225–30. PMID 4439458. 
  10. ^ Price, E.W. (1976). "The association of endemic elephantiasis of the lower legs in East Africa with soil derived from volcanic rocks". Transactions of the Royal Society of Tropical Medicine and Hygiene 70 (4): 288–95. doi:10.1016/0035-9203(76)90078-X. PMID 1006757. 
  11. ^ "'End in sight' for elephantiasis". BBC News. October 8, 2008. http://news.bbc.co.uk/2/hi/health/7659222.stm. Retrieved March 29, 2010. 
  12. ^ a b c d e The Carter Center. "Lymphatic Filariasis Elimination Program". http://www.cartercenter.org/health/lf/index.html. 
  13. ^ Hoerauf, Achim; Mand, Sabine; Fischer, Kerstin; Kruppa, Thomas; Marfo-Debrekyei, Yeboah; Debrah, Alexander Yaw; Pfarr, Kenneth M.; Adjei, Ohene et al. (2003). "Doxycycline as a novel strategy against bancroftian filariasis—depletion of Wolbachia endosymbionts from Wuchereria bancrofti and stop of microfilaria production". Medical Microbiology and Immunology 192 (4): 211–6. doi:10.1007/s00430-002-0174-6. PMID 12684759. 
  14. ^ Taylor, Mark J; Makunde, Williams H; McGarry, Helen F; Turner, Joseph D; Mand, Sabine; Hoerauf, Achim (2005). "Macrofilaricidal activity after doxycycline treatment of Wuchereria bancrofti: A double-blind, randomised placebo-controlled trial". The Lancet 365 (9477): 2116–21. doi:10.1016/S0140-6736(05)66591-9. Lay summary – The Journal of Young Investigators (November 2011). 
  15. ^ "Lymphatic filariasis". World Health Organization (WHO)
  16. ^ Burma D.P. (2010). Project Of History Of Science, Philosophy And Culture In Indian Civilization, Volume Xiii Part 2: From Physiology And Chemistry To Biochemistry. Pearson Education India. p. 49. ISBN 8131732207. http://books.google.com/books?id=4CaQ3-x3LXMC&pg=&dq#v=onepage&q=&f=false. 
  17. ^ Ghedin, E.; Wang, S.; Spiro, D.; Caler, E.; Zhao, Q.; Crabtree, J.; Allen, J. E.; Delcher, A. L. et al. (2007). "Draft Genome of the Filarial Nematode Parasite Brugia malayi". Science 317 (5845): 1756–60. doi:10.1126/science.1145406. PMC 2613796. PMID 17885136. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2613796. 

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