LeprosyPh. Ahmed Omar

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Introduction• Leprosy (also known Hansen’s

Disease)is an infectious chronic disease

caused by Mycobacterium leprae which

involves the skin and peripheral nerves.

• At 1873 , Gerhard Hansen was the first

person to identify the bacteria that cause

leprosy under microscope .

Epidemiology• According to WHO, between 1985 and 2010, the number

of registered cases fell from 5.4 million to 244,796.

• Most cases from India, Brazil, Bangladesh and Nigeria.

Tranmissition

• Respiratory droplets ( common )

• Skin contact

• Feeding

the person who talking medication over than weak is not

contagious.

about 95% of people have natural immunity against

M.leprea .

pathogenesis

Respiratory system or skin

Engulfed by macrophage but

Still alive ( replication )

peripheral nerves ( Schwann cell )

Nerves damage

N.B.- replication period is very slow (~ 13 day )

-Incubation period 2 –12 years as an average

Classification of leprosy • Ridley-Jopling classification:(cutaneous and neurological

disordrs)

o Tuberculoid Leprosy (TT)

• Hypopigmented macule

• High immunity

• No pain at lesions

o Lepromatous Leprosy (LL)

• Papules and nodules

• Pain at nodules and papules

• Low immunity

There also classes between e.g. Borderline

tuberculoid (BT), Borderline Leprosy (BB) and

Borderline lepromatous (BL)

Classification of leprosycont.

• WHO classification : ( number of lesions )

o Paucibacillary (PB) :

• Five lesions or less

• refers to TT and BT

o Multibacillary (MB) :

• Six lesions or more

• refers to BB, BL and LL

Symptoms in general

• White patches ( no pain )

• Swollen nerves

• Papule and nodule ( painful )

• Loss of sensation

• Loss of fingers and toes( due to injuries, secondary infections and cartilage destruction)

• Deformity of nose ( cartilage destruction)

• Claw hand ( nerve damage paralysis )

• Eye problems that may lead to blindness

etc…

Reactions of leprosy

• These are acute episodes that occur during the chronic

course of multibacillary leprosy. They may occur

spontaneously or may be precipitated by :

– treatment, infections, physical stress, injury,

operations, pregnancy, parturition or vaccination.

• Types of Reactions:

– Type I Reaction

– Type II Reaction

Type I Reaction

• Type of immunity:

– Type IV (cell mediated)

(delayed hypersensitivity reaction)

• Skin:

– Acute inflammation of existing lesions.

• Nerves:

– Swelling with pain & Tenderness →Paralysis.

• Systemic disturbances:

– None.

Type II Reaction

• Type of immunity:

– Type III (immune complexes).

• Skin:

– Erythema nodosum leprosum (ENL)

• Nerves: – Mild nerve damage.

• Systemic disturbances:

– Fever, malaise, iritis, dactylitis, arthritis, neuritis and

myositis. due to deposition of immune complexes in this

sites

Diagnosis

1. Clinical Manifestations: ( anesthesia, lesions, nerve

swelling ) .

2. Lepromin test : (immunity test to determine type of

leprosy ) by intradermal injection of heat killed bacteria.

Strongly positive : high immunity ( TT )

Weakly negative : ( BT )

Negative : low immunity ( BB, BL and LL)

If a normal person in an endemic area is lepromin

negative; he is liable to contract leprosy due to

absence of cell-mediated immunity

Diagnosis cont.

3. Skin Smear : ( Ziehl Neelsen stain ) for acid fast

mycobacteria.

o Absent bacteria : Paucibacillary Leprosy

o Present bacteria: Multibacillary Leprosy

4. Polymerase chain reaction ( PCR )

5. Nerve biopsy

N.B. Culture not applicable , as M.leprea not grow in

vitro

Treatment

multiple-Drug-Therapy ( MDT ) :

Dapsone ( bacteriostatic ) cheapest and most

important.

Rifampicin ( bactericidal ).

Clofazimine ( bacteriostatic and anti-inflammatory ).

Treatment cont.

In Paucibacillary Leprosy (PB) :

Day 1 :

Rifampicin ( bactericidal ) 600 mg / once monthly.

Dapsone ( bacteriostatic ) 100 mg.

Day 2 – 28 :

Dapsone ( bacteriostatic ) 100 mg / daily.

This course for 6 months

Treatment cont.

In Multibacillary Leprosy (MB) :

Day 1 :

Rifampicin 600 mg / once monthly

Dapsone 100 mg

Clofazimine (anti-inflammatory) 300 mg

Day 2 – 28 :

Dapsone 100 gm / daily

Clofazimine 50 mg / daily

This course for 12 months

Treatment cont.

• These medications are free from WHO

for leprosy patients anywhere on earth.

• Also we use prednisolone and thalidomide as anti-

inflammatory for leprosy reactions.

• Also, reconstructive surgery to repair nerves damage.

Prevention• Isolation الدقهلية-أبو زعبل -مستعمرة الجذام ) )

References

• www.uptodate.com

• http://www.who.int/mediacentre/factsheets/fs101/en/

• http://www.fda.gov/Drugs/DrugSafety/PostmarketDrugSafetyInformationforPatientsandProviders/ucm107296.htm

• https://web.stanford.edu/class/humbio103/ParaSites2005/Leprosy/history.htm

• http://www.leprosy.org/leprosy-faqs/

• http://www.cdc.gov/leprosy/symptoms/index.html

• http://apps.who.int/medicinedocs/en/d/Jh2988e/6.html