Elimination of Leprosy

Dr. C.R.RevankarMD, DPH

Public Health Physician & Leprologist

Contact :

3-15-14, Garden view Society, Bhavani Nagar, Marol, Andheri-

East, Mumbai(Bombay) - 400059, India

Email: macnir@bom3.vsnl.net.in& macnir@juno.com

Leprosy : How important for you

Leprosy(Hansen): Easy to diagnose, treat and cure.

3 million people are with leprosy related disabilities in the world.0.76 million new cases were identified in 2001(WHO 2002)

Objectives

After this lecture one should be able to-

Describe epidemiology of leprosy disease including disability in terms of time trends, impact of leprosy elimination strategies etc

Leprosy (Hansen’s) Disease

Chronic infectious disease caused by Mycobacterium leprae, affects nerves, skin and mucosa

Causes nerve damage & disabilities

- leading to social stigma, ostracism

& denial of human rights

Leprosy Case

A patient with active signs of leprosy- need or is under MultiDrugTherapy (WHO 1988)

Patients with residual signs are Inactive and Cured & should not be included for prevalence rate

Leprosy Elimination

Leprosy Elimination:Reducing Prevalence Rate (PR) to less than one active leprosy case per 10,000 population as a Public Health problem (WHO1991)

Priority:Communicable part of the disease (Transmission)

Leprosy Eradication/Extinction

Eradication: Absence of disease agent in nature in a geographic area after deliberate control measures (WHO2002)

Extinction: Specific disease agent no longer exists in nature or laboratory(WHO 2002)

A World Without Leprosy

Concept encompasses - early diagnosis, treatment, physical, socio-economic, psychological and rehabilitation of leprosy patients

No problems related to Leprosy in the world (ILA 1998)

Global public health strategy-1

To achieve leprosy elimination

• Adequate, regular MDT

• Leprosy awareness

• Leprosy Elimination campaign

• Special Action Projects for difficult areas (SAPEL)

Global public health strategy-2

• Action plan, review meetings• Resource mobilization, technical support, Capacity building, drug supply, monitoring, evaluation & documentation

Transmission

Organism: Mycobacterium leprae

Source: Untreated infectious patients (Multibacillary type)

Exit: Nasal mucosa, ulcerated skin

Entry: Airborne like TB

Epidemiology-1 • 1%-2% exposed population develop clinical disease• Incubation period: 3-5 years, can occur after several years

• Male:Female ratio: Generally 2:1

Epidemiology-2

Geographic variation

Lepromatous (MB type) -18% (Tanzania) to 63% (West Malaysia)

Neuritic leprosy-18% in India

Lucio type - Mexico

Epidemiology-3

• Deformities - 80% in Taiwan

7.6% in Cameroon

• Higher rate of Foot drop in

India and wrist drop in Japan

Prevalence rate—varies from

10-2500 per 10000 population

Epidemiology-4

Prevalence rate/10000

Agewise 1-5 5-14 >14

(slums) 47 150 247

slums non-slums schools

119 52 66

Global Leprosy Situation-2001

No.of cases registered: 635404Prevalence rate: 1.4 /10000New cases detected: 763317Detection rate: 11.9/100 000South-East Asia region contributed 76.9% of the global case load

Leprosy: top 6 countries-2001

0100000200000300000400000500000600000700000

India

Brazil

Nepal

Mya

nmar

Mad

gas'r

Moz

a'que

Prevalen Detection

Leprosy: 6 top countries

•6 top endemic countries: India, Brazil, Myanmar, Madgascar, Mozambique, Nepal contribute

85% of global case load:

(69% from India)• 91% of global case new cases

(81% from India)

Magnitude of Disabilities (1995)

0

500000

1000000

B'desh China India IndonesiaThailand Vietnam Guinea Nigeria

Diagnosis of Leprosy

More than 95% of cases can be diagnosed clinically even by paramedical workers

Skin smears for M.leprae would assist in suspected infectious cases

Biopsy/PCR may be needed rarely

Diagnosis- infectious leprosy

Detection of 5%-10% skin smear positive leprosy patients is more important as they infect others.

If no smear facility, detect 30%-40% of cases with multiple skin lesions.

Paucibacillary leprosy(PBL)

From “Leprosy” book by Yawalkar 2002

Multibacillary leprosy(MBL)

From “Leprosy” book by Yawalkar 2002

Classification for Treatment

•Multibacillary(MB) leprosy: >5 skin lesions:39%•Paucibacillary(PB) leprosy: 2-5 skin lesions:52%

•Single skin lesion PB:9%

(WHO 2002)

Multi Drug Therapy

•Kill all viable bacteria & make a patient non infectious

•Cure an active leprosy patient quickly from a public health point

Residual signs of inactivity may persist including persister bacilli in the deeper tissues

Impact of MDT Program

Cases cured: 12 million (2002)Fall in case load: 12 million (1977) to 0.64 million (2002)Deformities prevented:1-2 million

Relapse rate: < 1 /1000(WHO 2002)

Trend of Leprosy :1985-2001 -32 countries (WHO)

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1985 1987 1989 1991 1993 1995 1997 1999 2001

Prevalenc Detection

Child case /Total new cases-32 countries: 1985-1997 (WHO)

0

100000

200000

300000

400000

500000

600000

700000

800000

1985 1987 1989 1991 1993 1995 1997

Detection Children

Disabled among new cases-32 countries:1985-1997 (WHO)

0

100000

200000

300000

400000

500000

600000

700000

800000

1985 1987 1989 1991 1993 1995 1997

Detection Disabled

Cumulative disabled leprosy cases -32 countries-1985-1997

0500000

100000015000002000000

25000003000000350000040000004500000

1985 1987 1989 1991 1993 1995 1997

Prevalenc Disabled

Urban Leprosy Issues-1

• Leprosy Elimination in urban areas is challenged by -

Rapid increase in population, migration, slum/shanty towns, density, poor living conditions and violence

Urban Leprosy Issues-2

• Favorable to maintain reservoir of infection and transmission

• Difficulty in finding hidden cases, relapse and treatment completion, private health care participation

Post-Leprosy Elimination issues-1

• Continued transmission

• Early detection of MB case,

relapse, rifampicin resistance

• Sub clinical infection, carriers

• Eradication model, integration

• Uniform MDT for six months

Post-Leprosy Elimination issues-2

• Early detection & treatment of

reactions in 30%-40% of cases

• Prevention of nerve damage

• Prevention & Care of disabled

Post-Leprosy Elimination issues-3

• Patients dissatisfaction for residual

signs after MDT

• Immunoprophylaxis

• Chemoprophylaxis

• Immunotherapy

Partners in Leprosy Elimination

WHO, Nippon Foundation,

Novartis, World Bank, Danida,

ILEP agencies

National Governments &NGOs endemic countries