Leprosy Updated

8/22/2019 Leprosy Updated

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Leprosy


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A chronic infectious disease caused by the bacteriumMycobacteriumleprae

It is mainly a Granulomatous disease affecting: peripheral nerves and

mucosa of the upper-respiratory tract

Granulomatous - refers to granulomas which are lesions of epithelioid

macrophages

Leprosy (Hansens Disease)
http://www.granuloma.homestead.com/tuberculoid_leprosy_S72-6475-04.jpg


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A Little History

Gerhard Henrik Armauer Hansen wasa physician which first identified

Mycobacterium leprae as the cause of

leprosy in 1873

FYI

7/29/1841-2/12/1912
http://en.wikipedia.org/wiki/Image:Mycobacterium_leprae.jpeghttp://en.wikipedia.org/wiki/Image:Gerhard_Hansen.jpg


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A little taxonomy .

Kingdom Bacteria

Phylum Actinobacteria

Order Actinomycetales

Suborder Corynebacterineae

Family Mycobacteriaceae

Genus Mycobacterium

Species M. leprae


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Pathology

Gram-positive

Intracellular

Aerobic rod-shaped bacillus

With a waxy coating

M. leprae is unable to grow in vitro

This is thought to be due to the fact that it no longer has the genesneeded for independent growth

Because of its inability to grow on agar, nude mice and nine-banded

armadillos are used as animal models


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Clinical Features

Skin lesions, typically anaesthetic at the tuberculoid end ofthe spectrum

Thickened peripheral nerves

Acid-fast bacilli on skin smears or biopsy

Acid-fast is a property of Mycobacteria in which they aresistant to decolorization by acids during staining

This is a helpful diagnostic tool forM. tuberculosis andM.

leprae
http://en.wikipedia.org/wiki/Image:Leprosy.jpg


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SymptomsTuberculoid Borderline

Tuberculoid

Borderline

Lepromatous

Borderline Lepromatous

Skin

Infiltrated

lesions

Defined plaques,

irregular plaques,

healing centers

Polymorphic,

partially raised

edges, satellites

Papules, nodules,

punched-out

centers

Diffuse

thickening

Diffuse thickening

Macular

lesions

Single, small Several, any

size

Multiple, all sizes,

bizarre

Innumerable,

small

Innumerable,

confluent

Peripheral

Nerve

lesions

Solitary, enlarged

nerves

Irregular

enlargement of

several large

nerves,

asymmetrical

patterns

Many nerves

involved

symmetrical

patterns

Late neural

thickening,

asymmetrical

anaesthesia

and paresis

Slow, symmetrical

glove-and-

stocking

anaesthesia

Note: Contrary to popular belief leprosy does not cause body parts to simply fall off


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Tuberculoid leprosy- Patients lymphocytes respond toM. leprae in vitro

- Skin tests with lepromin elicit a strong positive response

- They also have a Th1- type response producing interleukin-2 and intergerons-

- These strong cell-mediated responses clear antigens, but cause local tissuedestruction

Lepromatous leprosy- Patients in this case do not mount a normal cell mediated response to

M. leprae, and in fact their lymphocytes do not respond to M. leprae invitro

- They are also unresponsive to lepromin

- They have specific T cell failure and macrophage dysfunction, andproblems producing interleukin-2 and intergerons-

- But they do produce Th2-type cytokins

Immunology


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Social Aspect WHO reported that at the start of 2007 there were 224,717 reported

cases (from 109 countries and territories) In comparison with the number of new cases detected in 2006 which

was 259,017, the number of new cases fell by more than 40,019 cases

(a 13.4% decrease)

In the last five years, the global number of new cases has dropped on

average by 20% per year. Also Leprosy has been around since about 300BC

FYI


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Geographic Rage For Leprosy


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Transmission

The transmission of leprosy is thought to occur through the respiratory

track

Infected individuals discharge bacilli through their nose and a healthy

individual breaths them in

But it is important to note that the extract mechanism is not known

The main reservoir is humans

Risk group: children, people living in endemic areas, in poor

conditions, with insufficient diet, or have a disease that compromises

their immunity (ie HIV)

In the 19th century leprosy was believed to be a hereditary ailment
http://upload.wikimedia.org/wikipedia/commons/thumb/e/e2/Leprosy_thigh_demarcated_cutaneous_lesions.jpg/800px-Leprosy_thigh_demarcated_cutaneous_lesions.jpg


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Diagnosis

Is clinical, by finding signs of leprosy and supported with the use ofacid-fast bacilli smear or skin biopsy

But this is contingent on experienced histopathologist

What doctors typically look for include: anaesthesia of skin lesions,

and peripheral nerve thickening and tenderness

There is no serological test

Note: The genome has been sequenced


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Treatment & Management Chemotherapy

- First line drugs are rifampicin, dapsone, and clofazimine- The WHO recommends that if a patient test positive in an acid-fast

skin smear they should be treated for multibacillary disease

- The patients bacterial load decides length of treatment (6-24 months)

- Patients tend to improve quickly with minimal side-effects

- Second line drugs are ofloxacin and minocycline- Tripledrug combinations have been used in cases where a patient has

only a single lesion

- Leprosy is combated with multidrug therapy to reduce the chance ofdeveloping resistance

- Since in the 1960s resistance to dapsone developed


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Multibacillary (MB or lepromatous) is a 24-month treatment of rifampicin, clofazimine, and dapsone.

Paucibacillary (PB or tuberculoid) is a six-month treatment of rifampicin and dapsone.
http://upload.wikimedia.org/wikipedia/commons/7/71/MDTRegimens.jpg


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Treatment & Management New Nerve Damage

- Patients with motor or sensory loss of 6 moths or less should receive a 6 monthtreatment of corticosteroids (a treatment for type 1 reactions)

Patient Education

- It is very important since within a few days of starting chemotherapy sincepatients will no longer be infectious and can live a normal life

- Currently there are few leper colonies left- Also care of limbs is very important

Preventing Disability

- Nerve damage produces anaesthesia, dryness and muscle weakness which inturn causes misuse of affected limbs causing ulceration and infection, leading

to deformity- Dryness can lead to skin cracking and ultimately infection

- Treatment involves soaking and applying oil- based creams to affected areas,also physiotherapy can help prevent contractures, muscle atrophy and overstretching of muscles
http://www.un.org/News/dh/photos/5-16leprosy.jpg


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Treatment & Management Immune-Mediated Reactions

- Type 1 reactions occur in borderline leprosy- Type 1 reactiondelayed hypersensitivity occurring at site of localizedM.

leprae antigens

- Skin lesions appear and are erythematous, and peripheral nerves becometender and painful

- Loss of nerve function can be sudden (ie foot-drop)

- Type 2 reactions occur in borderline lepromatous and lepromatous cases- Type 2 reactionerythema nodosum leprosum (ENL) results from immune

complex deposition

- The main symptoms are malaise, fever, and crops of small, pink nodules onface and limbs, and ENL may continue for years

- Management procedures include : control inflammation, pain, treat neuritis,

and halt eye damage

Vaccines

there currently isnt a vaccine against leprosy, but there are trials investigatingthe effectiveness of the BCG vaccine


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DiscussionThalidomide (Thalomid). This drug was originally developed as a sedative and

morning-sickness pill but was subsequently found to cause severe birth

defects; the Food and Drug Administration then banned it. Under the newregulations there are a number of restrictions on its use:

1. It can be used only for the treatment of erythema nodosum leprosum.

2. Doctors who prescribe the drug and pharmacists who dispense it mustregister with

Celgene, the company that produces it.

3. Women must have a negative pregnancy test 24 hours before taking thedrug.

4. Women must get weekly pregnancy tests during the first month oftreatment. Thereafter they

must get once-a-month pregnancy tests.

5. All thalidomide users must enroll in a registry at Boston University that

will record anypregnancies that occur and their outcomes.

6. All male patients must use condoms during sexual intercourse because thedrug is found in

semen.

http://www.kcom.edu/faculty/chamberlain/Website/tritzid/leprosy.htm


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Discussion

1) First of all lets assume that areas with highconcentrations of Leprosy could afford

Thalidomide in addition to their basic

treatment. What are the moral problems

with its prescription? What are some of the

additional problems that might arise if the

above regulations aren't followed?


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Discussion

2)What could explain such a drop in new Leprosy cases? Considering

the expense and length of treatment, not knowing the mode of

transitions and the fact that most areas that are affected are still

developing.

Free MDT,Reducing disease burden,

Preventing disability, Changing

the negative image, Working

with local governments and

agencies


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I got this off the net, I hope it helps, if anyone has any questions please email me.Can leprosy cause limbs to fall off?Leprosy does not cause flesh to rot and fingers and toes to drop off. In the past, limbs that have been damaged

because the person cannot feel pain have sometimes had to be amputated. Now that the disease can be detectedearly and cured completely, the need to amputate is very rare.

Who can get leprosy?Susceptibility: About 90% of the population is not susceptible to infection. Children are more susceptible than adults.Immunologic and epidemiologic studies suggest that only 10-20% of those exposed to M. lepraewill develop signs

of indeterminate Hansen's disease; only 50% of those with indeterminate disease will develop full-blown clinical

leprosy. Spontaneous healing also has been reported in tuberculoid leprosy.Host immunity: Where host cell-mediated immunity functions perfectly, organisms are routed and no diseasedevelops. If the individual has good immunity, organisms are contained and TT disease occurs. In subjects with

moderate immunity, a battle occurs and results in borderline types of leprosy. In persons with poor immunity, LL

occurs.

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Leprosy Updated