It is a unique presentation about current epidemiology of leprosy and its burden in India. It also includes information about various health programs related to leprosy.

1. Epidemiology and programs of
leprosy

2. Epidemiological parameters :
The two commonly used measures in the epidemiology of disease are:
1. Incidence (number of new cases occurring over a period of time)
2. Prevalence (number of all cases either at one point in time or over a period of time).
These two measures are related through the duration of disease
1. Incidence :
The true incidence of leprosy is very difficult to measure, as it is very low and not all cases are detected when
they occur.
There is a delay in detection between the onset of the signs of leprosy and the diagnosis, and this delay varies
over time and between countries.
New case detection per year is commonly used, as a proxy for incidence.
Operational factors such as:
1. The intensity of case detection,
2. Use of surveys,
3. Contact tracing,
4. Level of community awareness,
5. The quality and availability of health care have a profound effect on case detection rates

3. 2. Prevalence :
Point prevalence :
• The number of cases of leprosy registered for chemotherapy at the end of a calendar year
• Most commonly used measure of leprosy prevalence.
Period prevalence :
• All cases of leprosy existing during a year
• Which will be a higher number than point prevalence.
The registered prevalence :
• It is a proxy measure for the true prevalence.
• it includes existing cases that have not yet been detected.
• In the past, attempts were made to estimate the true prevalence and present the registered prevalence as a
percentage of that true or estimated prevalence.
The two factors that determine the registered prevalence are:
• The new case detection rate
• The duration of treatment

4. Age and Sex Specific Prevalence and Incidence Rates:
These indicators are used to remove the age and gender related bias in reporting the data of leprosy cases.
MB Proportion :
• It is the percentage of multibacillary cases among the total number of new leprosy cases detected during the
reporting year.
• People with MB leprosy are considered to be more infectious, and thus more likely to be responsible for
leprosy transmission.
• MB proportion is also a good indicator for estimation of drug requirements.
Lepromatous Rate :
• The proportion of cases with lepromatous leprosy, among the total number of cases.
• Indicator was in use in pre-MDT era when the definition of MB case was different than from that of today.
Deformity Rate :
• Percentage of patients with deformities among newly detected cases in a period of one year.
• This indicates the delay in time between a case getting infected and getting diagnosed and treated.

5. Child Proportion :
• This is the percentage of children among all new cases detected during the reporting year.
• A high child proportion would indicate an active and recent transmission of the disease.
• Since most of the child leprosy cases fall in paucibacillary type, the case detection through self-reporting is
bound to be low, as the patches are hardly noticeable in majority of the cases.
Basic Reproduction Rate :
• It is a measure of new cases arising from the index cases.
• This is an indicator of disease transmission.
• For a disease to be considered as an epidemic, the basic reproduction rate (BRR) must be more than one.
Treatment Completion Rate :
• This is the proportion of cases who complete the treatment in the stipulated time, i.e. 6 pulses of PB-MDT
in 9 months and 12 pulses of MB-MDT in 18 months period.
• For a leprosy control program, it is necessary to keep this rate as high as possible.
• If this rate is below 85% in any control program, the strategy calls for a review.

6. Global epidemiology of leprosy :
• Data were received from 160 countries in all 6 WHO regions.
• The prevalence rate for leprosy has previously been calculated per 10 000 population, the new case
detection rate per 100 000 population and the rate of grade-2 disability (G2D) per million population. On
the basis of expert advice, “million population” is used as the denominator for all rates in weekly
epidemiological report Sept. 2020
• The registered prevalence of leprosy (point prevalence), i.e. the number of cases on treatment at the end of
2019, was recorded as 177 175, with a corresponding prevalence rate of 22.7 per million population.
• Globally, 202 185 new cases were detected, for a new case detection rate of 25.9 per million population.
• During the reporting year, 14 981 new cases in children (<15 years) were detected among 202 185 cases, i.e.
7.4%.
• In 2019, 10 813 new cases with G2D were reported globally. 114451 2761

10. Epidemiology of leprosy in India :
At THE END OF 2018-
INDICATOR NO. OF PATIENTS
Registered prevalence 85302
Total no. of new case detection 1,20,334
No. of MB cases 62910
No. of females 46880
No. of children 9227
No. of cases with G2D 3666
No. of new child cases with G2D 84
No. of relapse 436
No. of other retreatment 5158
Treatment completion rate
MB 92
PB 96

11. Hyperendemic areas of India are in the north and east.
Currently, seven States in India contribute almost 3/4th of the total leprosy
burden, namely :
1. Bihar
2. Uttar Pradesh
3. Chhattisgarh
4. Jharkhand
5. Maharashtra,
6. Odisha
7. west Bengal
South Indian states to have reached elimination faster because of:
• Earlier implementation of MDT
• Better coverage
• Timely release from treatment (RFT).

12. EPIDEMIOLOGY OF LEPROSY :
AGENT
• The causative agent of leprosy, Mycobacterium leprae, was identified by Armauer Hansen in 1873.
• It is an :
1. Obligate intracellular pathogen that mainly infects macrophages and Schwann cells,
2. Acid-fast, straight/ slightly curved rod shaped
3. Gram-positive bacillus in clumps or bundles on microscopic examination.
4. Both extracellularly as well as intracellularly
• They are slow growing bacilli and one bacillus divides into two every 12–14 days.
• They do not produce toxins and occur
• The organism is killed by boiling and autoclaving. Its susceptibility to air, cold, water, drying and
disinfectants is uncertain.
• M. leprae can survive outside the human body for up to 45 days depending upon the environmental
conditions.
• M. leprae grows best in cooler tissues like the skin, peripheral nerves, upper respiratory tract and testes,
sparing warmer areas.

13. HOST FACTORS :
Age
• Leprosy can occur at any age, but is more commonly seen in the age group between 20 and 30 years.
• In endemic areas, the infection generally takes place during childhood. In low endemic areas, the
infection may occur in adulthood or later part of life.
• Increased proportion of child leprosy cases in the population has epidemiological significance as it
indicates presence of active transmission of the disease in the community.
• As transmission of the disease declines, It is seen more often in the older age group.
• Age distribution of lepromatous cases shows that the disease has a later onset as compared with
nonlepromatous cases.
Gender
• Leprosy occurs in both the sexes. However, males are affected more as compared to females, in the
proportion of 2:1.
• Sex difference is least among children below 15 years and is more marked among adults.
• More number of male cases could be attributed to :
1. Their greater mobility and increased
2. Opportunity for contact. Males are also more willing in
3. Reporting to the health facility for seeking treatment

14. Migration
• Due to migration of population from rural to urban areas, leprosy cases have increased in urban
areas in recent years. Most of the inhabitants are migrants from distant villages, the hygienic and living
conditions are poor, breathing space is greatly compromised (8–10 or even more people sharing the same
room) and other utilities. The conditions are nearly the same, both at home and place of work.
Two types of leprosy carriage can be noted:
• (1) The two way traffic, to and from the villages and slums
• (2) one way from slums to middle class localities where the population density and living conditions are
different from those in slums.
• Most of the household helps and maids working in middle class urban localities are originating from slums
inhabited by migrant population from the villages.
Household and Other Contacts
• The most consistent and most studied risk factor for development of leprosy is contact status.
• Intensity and physical distance from an index lepromatous leprosy case were directly associated with
increased risk of developing leprosy.

15. Ethnicity :
• The association between the epidemiology of leprosy and ethnicity has been a topic of interest but
there are no groups immune to leprosy although the rate of disease differs.
• In Micronesia the frequency of disability is very low whereas in China it is very high.
• Involvement of the lower branches of the facial nerve occurs more often in China but it is very rare
elsewhere
• some reactional states such as Lucio phenomenon occur mainly in Americas.
• These observations suggest that there may be genetically determined differences in the immune response
to M. leprae infection.
Familial Clustering
• The community clusters can be explained in terms of environmental factors of exposure, e.g. local
mycobacterial flora, and other environmental conditions to which all community people are exposed.
• But for the family clusters it becomes difficult to explain whether it is due to similar environmental
conditions or due to the close familial (genetic) relatedness, close contact with an affected family member
or a combination of all.
• The probability of finding familial occurrence of leprosy is higher in families that include a lepromatous
patient, than in those where it does not.

16. Nutrition :
• The disease is also known as a disease of poverty.
• To be able to control the disease, it is important to know which aspects of poverty play a role in
transmission and acquiring clinical signs of disease.
• A study conducted in Bangladesh showed that a recent period of food shortage was the only
socioeconomic factor that was found related to leprosy disease and not poverty as such.
• Malnutrition is known to lower immunity and make people more vulnerable to infectious
diseases.
Immunity
• Occurrence of the disease depends on susceptibility/ immunological status of an individual. Large
proportion of early lesions in leprosy heal spontaneously. Such self healing lesions suggest acquired
immunity.
• Cell mediated immunity is responsible for resistance to infection with M. leprae. Only a few persons
(about 1%) exposed to infection develop disease.
• Subclinical infections also contribute to development of immunity.
• A certain degree of immunity also appears likely through infections with other related mycobacteria.
there is good evidence that BCG vaccine can provide some protection against leprosy.
• Leprosy is like tuberculosis in that in the majority of cases, infection does not lead to clinical disease and
when the disease does develop, much of the damage is not caused by the infecting organism, but rather
by the immune responses.

17. Genetic Factors and Susceptibility
• General genes are involved in the response of the host to the mycobacteiral antigens. While some play an
adaptive role in innate immunity, others play a role in adaptive immune response.
• Studies suggest that, among monozygotic (identical) twins if one has leprosy, the other almost always had
leprosy, while this was not the case with dizygotic twins. Monozygous (MZ) twins share all the genes while
dizygous (DZ) twins share half the genes.
• The concordance was not limited to the disease per se; it was reflected also in the type of the disease
developed. Further, among the twins concordant for leprosy, 86.5% twins were concordant for leprosy
type.
• Host genetic factors responsible for susceptibility to leprosy can be approached in at least two ways:
1. Candidate gene studies can be carried out on genes of known function that have a possiblebiological role
in the control of infection or disease.
2. A non-targeted genome-wide linkage analysis, in which increased sharing of chromosomal regions by
affected individuals leads to identification of positional candidates.

18. ENVIRONMENTAL FACTORS :
• Humidity favors survival of the mycobacterium in the environment.
• The bacilli remain viable for about 9 days in dried nasal secretions and for almost 46 days in
moist soil at room temperature. Thus, risk of transmission increases with humid conditions.
Risk Factors :
• low education
• poor hygiene
• food shortages
• household crowding
• poverty

19. TRANSMISSION :
Source of Infection
• Man is the only natural reservoir of M. leprae and the only source of infection is an
untreated case of leprosy.
• Multibacillary cases are more important source of infection compared to paucibacillary
cases.
• Wild animals like armadillos, mangabey monkeys and chimpanzees show infections with M.
leprae. However, it is least likely that leprosy in wild animals could be a serious threat to
human beings.
Portal of Entry
• Respiratory route is the major portal of entry for the lepra bacilli.
• The possibility of infection by entry through skin, particularly broken skin cannot be ruled out.

20. Portal of Exit
• The bacilli are shed from nose, upper respiratory tract and the skin.
• Respiratory tract, especially nose is the major portal of exit of M. leprae.
• Millions of bacilli are discharged from the nasal mucosa of a bacteriologically positive case
during sneezing.
• Patients harbor most bacilli in their skin, but are seldom shed from intact skin.
• Lepra bacilli are found in sweat glands, sweat ducts, sebaceous glands and hair follicles.
• Bacilli can be shed from broken skin and ulcers of lepromatous cases.
• Only a small percentage (less than 3%) of these escaping bacilli are viable even in untreated
patients.
INCUBATION PERIOD
• Incubation period or latent period for leprosy is variable and unusually long.
• It may vary from few weeks to even 20 years with average incubation period of 5–7 years.
• A patient with paucibacillary leprosy may have shorter incubation period.

21. Mode of Transmission :
Inhalation (droplet infection):
The transmission of leprosy bacilli from person to person is mainly due to nasal droplet infection.
Contact:
To a smaller extent, the disease may also be transmitted by skin to skin contact.
In utero transmission:
• The youngest age of a reported leprosy case from Martinique was 3 weeks.
• High levels of IgG, IgM antibodies to M. leprae have been demonstrated in a higher percentage of 3–24
months old infants born to lepromatous mothers.
• Occasional M. leprae have been demonstrated in placenta and cord blood in humans and armadillos.
Transmission through ingestion (breast milk):
• Pedley showed leprosy bacilli in the epithelial linings of lactating mammary glands which are excreted in
milk. They also estimated that through a feed of 4 oz; the baby would ingest about 2 million leprosy bacilli.
• Despite all these observations, the fact remains that there is no definite evidence that
(i) breast milk with viable leprosy bacilli acts as a source of infection.
(ii) an infected breast milk induces any protective immune response in the child.

22. Inoculation following trauma:
Appearance of leprosy lesions has been observed after -
• thorn prick
• tattooing,
• Vaccination
• roadside injury
• after dressing of a wound in a leprosy hospital
• dog bite
• following injury sustained by a surgeon during operating a lepromatous leprosy patient.
Although it may be difficult to demonstrate the presence of M. leprae over the objects or instruments
involved in producing trauma in the instances mentioned, but this itself is sufficient to know that the
development of leprosy lesions were related to the site of trauma.
Conjugal :
• Leprosy acquired from marriage partners
• Only about 5%

23. Criteria of Leprosy Elimination :
WHO defines the “elimination of leprosy” as the achievement of prevalence rate
below 1 case per 10,000 population.
Limitations :
• The rate of 1 case per ten thousand is completely arbitrary.
• The rate intended (when the elimination strategy was launched) was based on the
actual prevalence and not the prevalence of registered cases.
• The strategy of elimination was based on the assumption that transmission would
be reduced, once the prevalence reached below a certain threshold. There is no
scientific basis for such a hypothesis when the fall in prevalence is the result of
shortening of the duration of treatment

24. Leprosy programs of India :
Establishment of the Indian Council of the British Empire Leprosy Relief Association in 1925 (renamed as
Hind Kusht Nivaran Sangh in 1947)
A committee appointed by the GOI in 1941 reviewed the extent of the leprosy problem in the country and
made specific recommendations for antileprosy work.
Another Expert Committee in 1954 that gave rise to concrete plans for the control of leprosy in India,
including legislation.
Launching of the National Leprosy Control Programme (NLCP) in 1955

25. National Leprosy Eradication Programme (NLEP) :
FORMATION :
The late Prime Minister of India, Smt Indira Gandhi, in her address to the World Health Assembly in May, 1981,
Made an appeal to all the developed countries, to help in leprosy eradication. she again asked the Indian scientists
to develop a leprosy eradication strategy.
Ministry of Health and Family Welfare constituted a Working Group to devise a new strategy and action plan for
the control and ultimate eradication of leprosy.
Following the recommendations of the Working Group, it was considered that a stage had arrived for undertaking
an eradication program for leprosy in the next 20 years. taking advantage of the twin developments of great
advances in chemotherapy of leprosy and extended reach of mass media.
The National Leprosy Eradication Programme was launched in 1983.

26. Phase 1 : (1993-94 to 2000)
• At the 44th World Health Assembly held in 1991, WHO and its member countries committed themselves
to eliminate leprosy as a public health problem by the year 2000, The GOI was also a signatory to this
commitment.
• The first World Bank supported project on NLEP was started in the year 1993-94, where the project
supported the vertical program structure formulated by GOI in the high endemic districts, while in the
moderate and low endemic districts, Mobile Leprosy Treatment Units (MLTUs) were established.
• The project was completed on March 31, 2000 with further 6 months’ extension to complete the
preparation of proposal for 2nd phase project.
• During this phase, against a target of 2 million cases, 3.8 million leprosy cases were newly detected and
on the whole 4.4 million leprosy cases were cured with MDT.
• The global target of leprosy elimination by end of the year 2000 was attained although prevalence rate in
India in March 2001 remained at 3.7/10,000 population.

27. Phase 2 : (2001-02 to 2004)
The Second World Bank supported National Leprosy Elimination Project was started for a period of 3 years
from 2001-02.
This project envisaged following strategy towards leprosy elimination in India:
• Decentralization of NLEP to states and districts
• Integration of leprosy services with GHS
• Leprosy training of GHS functionaries
• Surveillance for early diagnosis and prompt MDT, through routine and special efforts
• Intensified information, education and communication (IEC) activities using local and mass media
approaches
• Prevention of disability (POD) and care
• Monitoring and evaluation on regular (monthly/quarterly/ annually) basis as well as with special efforts
such as
independent evaluation, leprosy elimination monitoring, annual survey(s) and validation of progress towards
leprosy elimination, etc.

28. NLEP partners :
• State and UTs Governments
• World Bank
• WHO
• ILEP
• DANLEP
• NGOs
• Community, private medical practitioners
• Various concerned Government ministries/departments
At the end of the second phase as on March 31, 2005, the prevalence rate was 1.34/10,000.

29. Modified Leprosy Elimination Campaign (MLEC) :
Modified Leprosy Elimination Campaign approach was first started in India during 1997-98.
Objectives:
• To generate mass awareness about leprosy in the general population
• To give training to the General Healthcare Service staff who were not involved for leprosy service
delivery so far
• To detect the hidden leprosy cases in all the states/UTs and to put them under MDT.
First MLEC (1997-1999) helped in detection of as high as 4.5 lac new leprosy cases who received treatment with MDT
immediately.
Subsequently, four other MLECs were carried out in the country.
I- 1997-1999
II- 1999-2000
III- 2001-2002
IV- 2002-2003
V- 2003-2005
These MLECs helped in bringing out 9.9 lac new leprosy cases for treatment and cure in a short period of time.

30. Strategic plan of action (2004-05):
During the year 2004-05, the program focus was shifted from states to high and medium endemic
districts and blocks.
A strategic plan of action was drawn up with the following focus:
• Intensified focused action with strong supervisory support in 72 high priority districts with PR greater
than 5/10,000 and 16 moderately endemic districts
• Increased efforts put on IEC, Training and Integrated Service Delivery in identified high endemic
localities
• In 836 blocks in the country with PR greater than 5/10,000 as on March 31, 2004, a 2-week long Block
Leprosy Awareness Campaign was conducted through intensified IEC and through leprosy counseling
centers at subcenter level
INDICATORS March 2004 March 2005
States achieved elimination 17 24
Districts with PR >5/10,000 72 7
Blocks with PR >5/10,000 836 150
On December 31, 2005, PR recorded in the country was 0.95/10,000 population.

31. Prevalence
March 2001 3.7
March 2005 1.34
December 2005 0.95
March 2012 0.68
March 2018 0.67

32. Eleventh Five Year Plan (2007-2012) :
At the beginning of the 11th Plan, the country had ANCDR of 12.07/100,000 population.
Prevalence rate in March 2007 was 0.72/10,000 population.
The strategy under 11th Plan of:
(1) provision of high quality leprosy services for all persons affected by leprosy (PAL), through GHS including
referral services for correction of complications and chronic care;
(2) involvement of ASHA under NRHM for leprosy work;
(3) enhanced DPMR services for deformity in leprosy affected persons;
(4) enhanced advocacy in order to reduce stigma and stop discrimination against leprosy affected persons
and
their families
(5) capacity building among health service personnel in integrated setting both for rural and urban Area
(6) strengthen the monitoring and supervision component of the surveillance system.
At the end of the 11th Plan, the country achieved ANCDR of 10.35/100,000 population. Prevalence rate in
March 2012 was 0.68/10,000 population.

33. Twelfth Five Year Plan (2012–2017) :
Objectives of the 12th Plan are:
(1) Elimination of leprosy in all districts of the country
(2) strengthen disability prevention and medical rehabilitation of PAL
(3) reduction in the level of stigma associated with leprosy.
Strategies of the 12th Plan:
• Decentralized integrated leprosy services through GHS.
• Early detection and complete treatment of new leprosy cases.
• Carrying out household contact survey in detection of MB and child cases.
• Involvement of ASHA in the detection and complete treatment of leprosy cases under NRHM for leprosy
work.
• Strengthening of DPMR services.
• Information, education and communication activities in the community to improve self-reporting to PHC
and reduction of stigma.

34. Result-based planning:
To make the NLEP plan more compliant to the NRHM guidelines, the states/UTs were
advised that annual plans should be prepared as a result-based plan.
The results to be achieved at the end of the 12th Plan are:
• Improved early case detection.
• Improved case management.
• Reduced stigma.
• Development of leprosy expertise sustained.
• Research supported evidence-based program practices.
• Improved monitoring, supervision and evaluation system
• Increased participation of PAL in society.
• Program management ensured.

35. Activities under NLEP:
Diagnosis and treatment of leprosy-
Services for diagnosis and treatment (Multi drug therapy) are provided by all primary health centres and
govt. dispensaries throughout the country free of cost.
Training-
Training of general health staff like medical officer, health workers, health supervisors, laboratory
technicians and ASHAs are conducted every year.
Urban leprosy control-
To address the complex problems in urban areas, the Urban Leprosy control activities are being
implemented in urban areas having population size of more than 1 lakh.
IEC-
Intensive IEC activities are conducted for awareness generation and particularly reduction of stigma and
discrimination against leprosy affected persons.

36. NGO services under SET scheme-
Presently, 43 NGOs are getting grants from Govt. of India under Survey, Education and Treatment (SET)
scheme. The various activities undertaken by the NGOs are, IEC, Prevention of Impairments and
Deformities, Case Detection and MDT Delivery.
Disability Prevention and Medical Rehabilitation –
For prevention of disability among persons with insensitive hands and feet, they are given dressing material,
supportive medicines and micro-cellular rubber (MCR) footwear.
Supervision and Monitoring –
Programme is being monitored at different level through analysis of monthly progress reports, through field
visits by the supervisory officers and programme review meetings held at central, state and district level.

37. Initiatives:
Involvement of ASHA–
To facilitate involvement OF ASHA workers, they are being paid an incentive as below:
i. On confirmed diagnosis of case brought by them – Rs. 250/-
ii. On completion of full course of treatment of the case within specified time – Pauci bacillary
(PB) leprosy case – Rs. 400/- and Multibacillary (MB) Leprosy case – Rs. 600/-. The scheme
has been extended to involve any other person who brings in or reports a new case of
leprosy.
iii. An early case before onset of any visible deformity – Rs 250
iv. A new case with visible deformity in hands, feet or eye – Rs 200
E Newsletter-
• A Quarterly publication from the house of CLD.
• NLEP Newsletter will share guidelines, feedback/best practices, experiences and activities
undertaken in the programme in coordination with partner/ States/NGOs/Institutes/Medical
Colleges & Associations etc.

38. Leprosy Case Detection Campaigns (LCDC),
• A unique initiative of its kind under NLEP, is being implemented in high endemic districts of the
country, in line with Pulse polio Campaign by Central Leprosy Division.
• To detect the hidden leprosy cases,
• In this campaign each and every person in a house in the selected high endemic districts will be
examined to detect all hidden cases in the community.
• This will interrupt the transmission of the disease in the community, and expedite achievement of
elimination status at district and sub-district level.
GIS Mapping
• GIS mapping was used in analysis of annual data received from states and UTs for the financial year
2014-15.
• Preparing GIS maps enabled visualization of district wise data pertaining to annual new case detection
rate and prevalence of the disease spatially which was previously done manually.

39. Final Push Strategy :
By WHO
From (2000-2005)
The components under the strategic plan were:
• Reducing the reservoir of infection by improving access to MDT services.
• Curing patients and preventing suffering and disabilities.
• Essential technical support.
• Phasing out.
In order to make a “final push” to detect and cure all the remaining leprosy cases in the World and
thereby eliminate leprosy from every country by the year 2005, a Global Alliance for the Elimination of
Leprosy (GAEL) was created in November 1999 with initiative of WHO.
The Government of India sets the goal of elimination of leprosy, i.e. to reduce the number of cases to less
than 1/10,000 population by the year 2005, in the National Health Policy 2002.

40. Global leprosy strategy (2016-2020) : (Accelerating towards leprosy free world )

41. PILLARS AND COMPONENTS :
1. Strengthen government ownership, coordination and partnership
2. Stop leprosy and its complications
3. Stop discrimination and promote inclusion
Guiding principles :
1. Responsibility of national governments and strengthening partnerships
2. Quality leprosy services with children and women as the focus
3. Sustaining expertise in leprosy
4. Participation of persons affected by leprosy in leprosy services
5. Focus on research to support leprosy control

43. Thank you