Leprosy (Hansen’s Disease)

1. Leprosy (Hansen’s Disease)

The topic of the lecture:
Leprosy (Hansen’s Disease)
Professor Kutmanova A.Z.

2. What is Leprosy?

• It is a disease of Historical importamce
• Worlds oldest recorded disease
• Stigmatized disease

3. Introduction

• Leprosy is a chronic infectious disease caused
by Mycobacterium leprae, an acid-fast, rodshaped bacillus.
• The disease mainly affects the skin, the
peripheral nerves, mucosa of the upper
respiratory tract and the eyes.
• Leprosy is curable and treatment provided in
the early stages averts disability.

4. Introduction

• Multidrug therapy (MDT) treatment has been made
available by WHO free of charge to all patients
worldwide since 1995.
• It provides a simple yet highly effective cure for all
types of leprosy.
• Elimination of leprosy as public health problem (with
a prevalence less than 1 case per 10 000 persons) was
achieved globally in the year 2000.
• More than 16 million leprosy patients have been
treated with MDT over the past 20 years.

5.

6. Gerhard Armauer Hansen

1868 - Identifies First
microorganism
Global Project on the History of Leprosy
http://www.leprosyhistory.org/graphics/gallery/hansen.jpg

7. Leprosy is caused by Mycobacterium leprae

• Bacilli may
present in singles,
can be intracellular.
• Agglomerates.
• Bacilli bound by
lipid like substance
(Glia)
• Masses are Globi
• Appear cigar
bundles.
Scollard, DM et al. 2006. “The continuing challenges of leprosy.”
Clinical microbiology reviews 19, no. 2: 338-81.

8. Cultivation

Not possible
Can be propagated in Foot pads of Mice
Granulomas develop at the site of inoculation.
Nine banded armadillo highly susceptible.
Chimpanzees
Generation time 12 -13 days.
Average may be 8- 42 days

9. Important Experimental Animal

10. Most Important experimental Animal

11. Transmission

Nasal/oral Droplets
Dermal Inoculations

12. Classification (Madrid)

13. Symptoms

14. Types of Leprosy

Depending on clinical features, leprosy is
classified as:
• Indeterminate Leprosy (IL)
• Paucibacillary Leprosy (PB)
• Borderline Tuberculoid Leprosy (BT)
• Borderline borderline Leprosy (BB)
• Borderline lepromatous Leprosy (BL)
• Multibacillary Leprosy (MB)

15. WHO classification

• Two Groups:
1 Paucibacillary
2 Multibacillary
• Paucibacillary (PB): the number of M. leprae in
the body is small (less than 1 million) and a
skin smear test is negative. The patient
presents five or fewer skin lesions. Most cases
of leprosy are PB.

16. WHO classification

• 2 Multibacillary
• M. leprae can multiple in the body almost
without any check and is thus present in high
numbers. The bacillus has likely spread to
almost all areas of skin and peripheral nerves.
A skin smear test is positive and the patient
presents more than five skin lesions.

17. Bacteria Resides in Cooler Parts of the Body

Skin
Peripheral Nerves
http://www.nlm.nih.gov

18. Symptoms & Diagnosis: (1) Skin Lesions

Symptoms & Diagnosis:
(1) Skin Lesions
Worobec, Sophie M. 2009. “Treatment of leprosy/Hansen's disease in
the early 21st century.” Dermatologic therapy 22, no. 6: 518-37.

19. Immunocompromised individuals are more susceptible to disease

20. Mechanism of Nerve Damage

1.Entry Through
Blood Vessels
2. Inflammatory
Response
3. Demyelination
Scollard, DM et al. 2006. “The continuing challenges of leprosy.”
Clinical microbiology reviews 19, no. 2: 338-81.

21.

Outcomes of Nerve Damage
Sensory Loss
Paralysis
Deformities
Leprosy: eMedicine Infectious Diseases
http://emedicine.medscape.com/article/220455-overview

22. Sensory Loss Can Lead to Secondary Infections and Severe Deformities

International Federation of Anti-Leprosy Associations (ILEP)
http://www.ilep.org.uk/en/

23.

24.

25. 1941: Discovery of Dapsone

• Targets dihydropteroate
synthase (DHPS)
• Inhibits nucleic acid
synthesis

26. 1964: Dapsone Resistance from Missense Mutations in DHPS

DHPS - dihydropteroate synthases
Matsuoka, Masanori M. 2010. “Drug Resistance in Leprosy.” Japanese journal of infectious diseases 63, no. 1: 1-7.

27. 1960’s: Rifampicin and Clofazimine Discovered

• Rifampicin (Rifampin):
Inhibit RNA synthesis
• Clofazimine:
Anti-inflammatory

28. 1981: WHO Proposes Multi-Drug Therapy (MDT)

• Combination of DAPSONE, RIFAMPICIN, and
CLOFAZIMINE
+
+

29.

The Nippon Foundation
http://www.nippon-foundation.or.jp/eng/

30. 1995: WHO Distributes MDT Drugs for Free to Worldwide Patients

31. 1999: Global Alliance to Eliminate Leprosy As a Public Health Problem

32. Obstacles to Eliminating Leprosy in Endemic Countries

STIGMA
World Health Organization. 2001. “Leprosy: Learning from Success.”
WHO Publications on Leprosy.

33. Overcoming Stigma

Mass Media
Integrated Primary Health Services
Education & Training

34.

Worobec, Sophie M. 2009. “Treatment of leprosy/Hansen's disease in the early 21st century.”
Dermatologic therapy 22, no. 6: 518-37.

35.

In 2016 WHO has launched a new
global strategy – “The Global Leprosy
Strategy 2016–2020: Accelerating
towards a leprosy-free world”
The targets of the new global strategy to be met by 2020 are:
• Zero disabilities among new paediatric patients.
• A grade-2 disability rate of less than 1 case per 1 million people.
• Zero countries with legislation allowing discrimination on basis of
leprosy.