Leprosy

epidemiology, clinical features, diagnosis and prevention

1. LEPROSY Dr S wati S hikha MBBS MD DNB Assistant Professor Dept. o f Community Medicine

2. Contents Introduction Problem statement Epidemiological determinants Mode of transmission Pathogenesis Clinical features Diagnosis Complications Prevention & control Global leprosy strategy 2016 - 2020 2/13/2021 2

3. Introduction Oldest disease of mankind ( known since the days of Susruta and Charakas ) An important cause of permanent disability Full of superstitions and stigma besides physical suffering Was considered highly contagious incurable disease transmitted by inheritance Mahatma Gandhi: an important role to remove discrimination CO was isolated by Dr. G A Hansen of Norway India: “ Kusht ” – eating away Dapsone monotherapy was started MDT use was recommended and started 2/13/2021 3

4. Problem statement Globally: Global prevalence in the year 2016: 0.23/10,000 population Eliminated at global level in the year 2000 Major burden of new cases was from India, Brazil and Indonesia during 2016 A reduction of new cases by 3.4% was reported during 2017 as compared to 2016. India : Elimination status was achieved at national level in 2005 Few states are still to achieve elimination status: CG, Bihar, Chandigarh, Goa, Odisha, Dadra & Nagar Haveli and Lakshadweep. India is still among the “Global Priority Countries” 2/13/2021 4

5. Epidemiological determinants AGENT: M. Leprae : gram positive, acid fast slowly multiplying organism with strong affinity for schwann cells of peripheral nerves Man : only source of infection HOST: Maximum incidence: 10 – 20 years CMI is protective ENVIRONMENT: More in tropical and sub tropical climate Overcrowding & lack of ventilation predisposes 2/13/2021 5

6. Mode of Transmission Droplet infection: Major mode Direct contact: with an open and active lesion 2/13/2021 6

7. Pathogenesis Diverse clinical spectrum based on CMI Following exposure ~ 95% subjects possess adequate CMI hence donot exhibit S & S Those with poor immunity exhibit clinical symptoms and signs Spectrum of severity depends on CMI Test for CMI: Lepromin Test 2/13/2021 7

8. Lepromin test An intra dermal test to detect CMI against Leprosy Prodecure : 0.1ml of antigen ( lepromin ) ID into flexor surface of forearm by 25 G hypodermic needle 2 types of reactions: Early reaction of Fernandez: within 24 to 48 hrs and disappears after 3 – 4 days Erythema and induration (diameter of red area> 10 mm at the end of 48 hours) Late reaction of Midsuda : positive after 3 – 4 weeks. Read at 21 days Nodules > 5mm in diameter Midsuda reaction is preferred over Fernandez reaction Early reaction: soluble constituents of bacilli & Late reaction: bacillary component of antigen 2/13/2021 8

9. Applications of Lepromin test Classification of leprosy: Strongly positive in tuberculoid leprosy (good CMI) Negative in lepromatous leprosy (Failure of CMI) Prognostic value : Shows an immunological shift in the behaviour of a case. Predictive value : Gives an indication of the risk of disease among contacts of open cases Epidemiological value : Incidence and prevalence of infection among children Most children in 1 st 6 months are lepromin negative and become positive progressively as their age advances 2/13/2021 9

10. Clinical features Cardinal features : Hypopigmented or erythematous skin patch with a definite sensory loss Thickened tender peripheral nerve with sensory deficit Positive slit skin smear : BI and MI Presence of one or more cardinal features is diagnostic of leprosy 2/13/2021 10

11. Complications Lepra reaction: A hypersensitivity reaction that occurs in any type of leprosy It may occur in patients under treatment or after completion of treatment Precipitating factors: vaccination, pregnancy & delivery, intercurrent infection and mental & physical exhaustion 2 types of reaction: Type I (Reversal reaction) and Type II (ENL) 2/13/2021 11

12. Type I lepra Reaction/ reversal reaction A delayed type of hypersensitivity reaction Skin lesions: sudden appearance of reddish, swollen, warm, painful and tender lesions Nerve close to skin may be enlarged, tender and painful with loss of its function Other organs are not affected Signs of severe reversal reaction: Loss of nerve function Pain/ tenderness in one/more nerves Red, swollen skin patch on face or overlying another major nerve trunk Skin lesion anywhere that becomes ulcerated Marked edema of hand, feet or face 2/13/2021 12

13. Type ii lepra reaction/ enl Known as Erythema nodosum leprosum Antigen antibody reaction Signs of severe ENL: Pain/ tenderness in one or more nerve with or without loss of nerve function Ulceration of ENL nodules Pain of eyes with or without redness and loss of visual acuity Painful swelling of fingers Marked arthritis or lymphadenitis 2/13/2021 13

14. PREVENTION & CONTROL 2/13/2021 14

15. Principles & strategies for leprosy control Early detection & treatment of cases: Will lead to decrease in pool of infection in the community Also will prevent development of disability Case finding approaches: Passive/ Active Treatment is done with MDT Disability prevention & medical rehabilitation (DPMR): Aim: maintain or restore the functioning of the patient so that the person can lead a life with full dignity and independence 2/13/2021 15

16. Case detection approaches Passive case finding : Voluntary reporting of cases Depends on the awareness and perception of the community about the disease and its preventability Active case finding : House to house search for cases are done 3 types: Contact survey: prevalence < 1 case/1000 population Group survey: prevalence ≥ 1 case/1000 population (school children, slum population, military recruits) Mass survey: prevalence ≥ 10 case/ 1000 population (every individual survey for hyperendemic areas) 2/13/2021 16

17. treatment Regular and complete treatment with MDT is the only way to cure the patient and to prevent transmission Duration : MB: 12 months to be completed in 18 months PB: 06 months to be completed in 09 months MB Cases (> 5 skin lesions) PB Cases (1-5 skin lesions) Rifampicin 600 mg once monthly (supervised) Rifampicin 600 mg once monthly (supervised) Dapsone 100 mg daily Dapsone 100 mg daily Clofazimine 300 mg once monthly( supervised and 50 mg daily 2/13/2021 17

18. Definitions Case of leprosy : a person showing clinical signs of leprosy with or without bacteriological confirmation of diagnosis and who has not yet completed full course of treatment with MDT Adequate treatment : completion of a regimen of MDT within a reasonably short period of time Regular treatment : if a patient has received MDT for atleast 2/3 rd of the months in any interval of time Newly diagnosed case : person who has been newly diagnosed with leprosy and who has not taken MDT in the past Defaulter case : A leprosy patient on MDT who has not collected treatment for 12 consecutive months Relapsed case : a patient whose therapy was terminated after completing an adequate course of MDT and now again develop new signs & symptoms of the disease. 2/13/2021 18

19. surveillance Clinical surveillance of cases after completion of treatment is an important part of current recommendations of MDT It is essential for the assurance of long term success of treatment and for early detection of any relapse Paucibacillary : patient is examined clinically at least once a year for minimum of 2 years after completion of treatment Multibacillary : patient is examined clinically atleast once a year for a minimum period of 5 years after completion of treatment Patient who has completed required period of surveillance and shows no evidence of relapse is considered to have completed surveillance. 2/13/2021 19

20. Disability prevention Disability is a result of nerve damage due to leprosy or due to lepra reaction Ways to prevent leprosy: Early diagnosis and treatment of leprosy before nerve damage sets in Early identification of lepra reaction and its management Care of wound or ulcer: education of community about self care practices The basic practices are: Care of the dry skin by applying oils Use of suitable footwear Scraping the hard skin Prevention of injury 2/13/2021 20

21. rehabilitation It includes all measures to decrease the impact of disability so that the person affected with leprosy can lead a life with highest possible level of independence in all domains of health- physical, mental, functional and social. Different types of rehabilitation that are applicable in leprosy are: Medical : MDT, MCR footwear, self care kit, re constructive surgeries if necessary Social and psychological : empower the patient with disability for equal participation in every sphere of life Vocational rehabilitation : this is required for encouraging livelihood and promoting economic independence. 2/13/2021 21

22. Evaluation of control activities To assess the impact of control operations on the endimicity of the disease To compare results between different times and places Indicators required for such evaluation are as follows: Epidemiological indicators Core indicators for monitoring progress Indicators for evaluating case detection Indicators for assessing the quality of services 2/13/2021 22

23. Epidemiological indicators Required to evaluate the effectiveness of the programme Indices are: Incidence: most sensitive index of transmission of disease Only index for measuring effectiveness of measures taken Useful in monitoring the success of a control programme Prevalence: Measure of the case load Useful in the planning of treatment services 2/13/2021 23

24. Indicators for monitoring progress The number and rate of new cases detected per 100000 population per year Rate of new case with grade 2 disability per 100000 population per year Treatment completion or cure rate 2/13/2021 24

25. Indicators for evaluating case detection Proportion of new cases presenting with grade 2 disability/ impairment Proportion of child cases among new cases: A high child proportion may be a sign of active and recent transmission of disease Valuable for calculating drug requirement Proportion of female patient among new cases Proportion of multibacillary cases among new cases 2/13/2021 25

26. Indicator for assessing the quality of services Proportion of new cases verified as correctly diagnosed Proportion of treatment defaulters Number of relapses Proportion of patients who develop new/ additional disability during MDT 2/13/2021 26

27. Voluntary organisations Voluntary organisations working for anti leprosy activities in India are: Hind Kusht Nivaran Sangh Gandhi Memorial Leprosy Foundation German Leprosy Relief Association Damien Foundation Danish Save the Child Fund 2/13/2021 27

28. Global leprosy strategy 2016 - 2020 Theme adopted by WHO : Global Leprosy Strategy 2016 – 2020: Accelerating towards a leprosy free world. Ultimate vision: Leprosy free world Key targets of this strategy: Rate of newly diagnosed leprosy with visible deformities: < 1 per million Grade II deformity among children affected with leprosy: 0 Number of countries with legislation allowing discrimination on the basis of leprosy: 0 2/13/2021 28

29. Thank you 2/13/2021 29