Leprosy

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Template:DiseaseDisorder infobox | }} Hansen's disease is an infectious disease caused by a bacterium called Mycobacterium leprae. The bacterium is an aerobic, acid fast, rod-shaped (bacillus) mycobacterium. The modern term for the disease is named after the discoverer of the bacterium, Gerhard Armauer Hansen. Until recently, Hansen's disease along with several other skin disease was called Leprosy.

For the malady found in the Hebrew Bible, see the article Tzaraath. For the album by the band Death, see Leprosy (album).

1 Treatment
2 Clinical features
3 Incidence
4 Risk groups
5 Term "Leprosy"
6 Asylums
7 Famous people with leprosy
8 See also
9 References
10 External links

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Treatment

Historically, leprosy was an incurable and disfiguring disease. Lepers were shunned and sequestered in leper colonies. Today, leprosy is easily curable by multidrug antibiotic therapy (MDT). The main challenges in the eradication of Hansen's disease are in reaching populations that have not yet received multidrug therapy services, improving detection of the disease, providing patients with high-quality services and affordable drugs, and fighting social taboos about the disease where patients are considered to be "unclean", or "cursed by God" and outcasts. The last issue is important to address, because in such societies, patients may be forced to hide their condition (and thus not to seek treatment) in order not to be discriminated against, since the lack of awareness about Hansen's disease leads people to falsely believe that the disease is highly contagious and incurable. Since 1995, the World Health Organization (WHO) has provided all endemic countries with free MDT, supplied through Ministries of Health. In December 2005, an agreement was signed between the WHO and the pharmaceutical company Novartis to extend this free provision until at least the end of 2010.

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Clinical features

The disease is caused by a mycobacterium which multiplies very slowly (once every two weeks compared to other bacteria which can range from daily to just 20 minutes) and mainly affects the skin, nerves, and mucous membranes. The organism has never been grown in bacteriologic media or cell culture, but has been grown in mouse foot pads and more recently in nine-banded armadillos. It is related to M. tuberculosis, the mycobacterium that causes tuberculosis. The difficulty in culturing the organism appears to be due to the fact that the organism is an obligate intra-cellular parasite that lacks many necessary genes for independent survival. The complex and unique cell wall that makes the mycobacterium family difficult to destroy is apparently also the reason for the extremely slow replication rate.

The mode of transmission of Hansen's disease remains uncertain. Most investigators think that M. leprae (also called "Hansen's bacillus") is usually spread from person to person in respiratory droplets. What is known is that the transmission rate is very low. In addition, approximately 95% of the population is naturally immune. Also, contrary to popular belief, Hansen's disease does not cause rotting of the flesh; however, due to the body's extensive attempts to rid itself of the bacterium, defense such as inflammation, cytokines, activated macrophages and other mechanisms cause tissue destruction and regeneration leading to excessive growth and eventually mutilation.

This chronic infectious disease usually affects the skin and peripheral nerves but has a wide range of possible clinical manifestations. Patients are classified as having paucibacillary (tuberculoid leprosy) or multibacillary Hansen's disease (lepromatous leprosy). Paucibacillary Hansen's disease is milder and characterized by one or more hypopigmented skin macules. Multibacillary Hansen's disease is associated with symmetric skin lesions, nodules, plaques, thickened dermis, and frequent involvement of the nasal mucosa resulting in nasal congestion and epistaxis (nose bleeds).

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Incidence

Other than humans, the only animals known to be susceptible to leprosy are the armadillo, mangabey monkeys, rabbits, and mice (on their footpads).

According to recent figures from the World Health Organization (WHO) new cases detected worldwide has decreased by approximately 107,000 cases or 21% from 2003 to 2004. This decreasing trend has been consistent for the past three years. In addition the "global registered prevalence" of leprosy was 286,063 cases with 407,791 new cases being detected during 2004.

In 1999, the world incidence of Hansen's disease was estimated to be 640,000; and in 2000, 738,284 cases were identified. In 1999, 108 cases occurred in the United States. In 2000, the World Health Organization (WHO) listed 91 countries in which Hansen's disease is endemic, with India, Myanmar, and Nepal having 70% of cases. In 2002, 763,917 new cases were detected worldwide, and in that year the WHO listed Brazil, Madagascar, Mozambique, Tanzania and Nepal as having 90% of Hansen's disease cases.

Worldwide, one to two million people are permanently disabled because of Hansen's disease. However, persons receiving antibiotic treatment or having completed treatment are considered free of active infection. India has the greatest number of leprosy cases, with Brazil second and Myanmar third.

Hansen's disease is one of the infectious diseases tracked passively by the Centers for Disease Control and Prevention. Its prevalence in the United States has remained low and relatively stable. There are decreasing numbers of cases worldwide, though pockets of high prevalence continue in certain areas such as Brazil, South Asia (India, Nepal), some parts of Africa (Tanzania, Madagascar, Mozambique) and the western Pacific.

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Risk groups

Those having close contacts with patients with untreated, active, predominantly multibacillary disease, and persons living in countries with highly endemic disease are at risk of contracting the disease. Recent research suggests that there is genetic variation in susceptibility. The region of DNA responsible for this variability is also involved in Parkinson's disease, giving rise to current speculation that the two disorders may be linked in some way at the biochemical level.

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Term "Leprosy"

Sufferers of Hansen's disease have historically been known as lepers, however this term is falling into disuse as a result of the diminishing number of leprosy patients and the pejorative connotations of the term. In fact the term now that is most widely accepted among people and agencies working in the field of leprosy is "people affected by leprosy". The terms "leprosy" and "lepers" can also lead to public misunderstanding because the Bible uses these terms in reference to a wide range of skin conditions other than Hansen's disease.

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Asylums

There are still a few leper colonies around the world, in countries such as India and the Philippines.

Western humanitarian and church organizations regularly send relief supplies, including handmade "leper bandages"; bandages knitted or crocheted out of cotton, for greater breathability and durability than traditional gauze. The bandages can also be washed, sterilized, and reused making them arguably more cost effective as well. Though leper bandages can be machine made, the colony inhabitants tend to appreciate the handmade variety.

In 2001, government-run leper colonies in Japan came under judicial scrutiny, leading to the determination that the Japanese government had mistreated the patients, and the District Court ordered Japan to pay compensation to former patients [1]. In 2002, a formal inquiry into these colonies was set up, and in March of 2005, the policy was strongly denounced. "Japan's policy of absolute quarantine... did not have any scientific grounds." Many children of those with Hansen's disease were executed by staff at colonies up to the 1950s. [2]

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Famous people with leprosy

Baldwin IV, Latin King of Jerusalem (1161-1185, reigned 1174-1185)
Uzziah, the greatest King of Judah since Solomon
Father Damien, a Roman Catholic missionary who helped lepers on the Hawaiian island of Molokai and also died of the disease.
Hallgrímur Pétursson, Iceland's most famous and adored priest and poet, died from leprosy.

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References

Icon Health Publications. Leprosy: A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References. San Diego: Icon Health Publications, 2004. ISBN 0597840067.
Tayman, John The Colony : The Harrowing True Story of the Exiles of Molokai, Simon & Schuster, 2006. ISBN-10 074323300X/ISBN-13 9780743233002
IT Conversations Tech Nation interview with author John Tayman (MP3 format; runtime: 00:23:20, 10.7 mb, recorded 2006-02-07)

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