Elimination of Leprosy
Dr. C.R.Revankar
MD, DPH
Public Health Physician & Leprologist
Contact :
3-15-14, Garden view Society, Bhavani Nagar, Marol, AndheriEast, 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 toDescribe 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
(slums) slums 119
1-5
47 52
5-14
150
>14
247 schools 66
non-slums
Global Leprosy Situation-2001
No.of cases registered: 635404 Prevalence rate: 1.4 /10000 New cases detected: 763317 Detection rate: 11.9/100 000 South-East Asia region contributed 76.9% of the global case load
Leprosy: top 6 countries-2001
700000 600000 500000 400000 300000 200000 100000 0
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)
1000000
500000
0
B'desh Thailand China Vietnam India Guinea Indonesia 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)
4500000 4000000 3500000 3000000 2500000 2000000 1500000 1000000 500000 0 1985 1987 1989 1991 1993 1995 1997 1999 2001 Prevalenc Detection
Child case /Total new cases -32 countries: 1985-1997 (WHO)
800000 700000 600000 500000 400000 300000 200000 100000 0 1985
1987
1989
1991
1993 Children
1995
1997
Detection
Disabled among new cases -32 countries:1985-1997 (WHO)
800000 700000 600000 500000 400000 300000 200000 100000 0 1985 1987 1989 1991 1993 1995 1997
Detection
Disabled
Cumulative disabled leprosy cases -32 countries-1985-1997
4500000 4000000 3500000 3000000 2500000 2000000 1500000 1000000 500000 0 1985 1987 1989 Prevalenc 1991 1993 1995 Disabled 1997
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