Leprosy (Hansen’s Disease).pptx

leprosy

1. Epidemiology of Leprosy & Contagious Disease Dr. Khem R Sharma Assistant Professor School of Public Health & Community Medicine

2. Introduction Leprosy (Hansen's disease) is a chronic infectious disease caused by M. Ieprae that mainly affects the peripheral nerves. It also affects the skin, muscles, eyes, bones, testes and internal organs In Nepal, leprosy is known since ancient times as kustha rog and attributed to punishment or curse from God

3. Disease is divine punishment Curse of God Due to sin Incurable Highly contagious Nepalese Societal Beliefs Towards Leprosy

4. Modern-day leprosy dates from 1873 when Hansen of Norway discovered M. leprae . After a long period without any cure, introduction of sulphone drugs in the treatment of leprosy in 1943 marked the beginning of the era of case-finding and domiciliary treatment. The decade of 1980s has witnessed a change in the strategy of leprosy control from mono-therapy to multidrug therapy, due to widespread emergence of dapsone -resistant strains.

5. Epidemiology In 1991, WHO Member States resolved to decrease the level of leprosy in the world by over 90 per cent Elimination of leprosy as a public health problem is defined as a prevalence rate of less than one case per 10 000 persons. This has now been accomplished, and the overall target for the global elimination of leprosy as a public health problem has been attained According to WHO, global registered prevalence of leprosy at the end of 2015 was 176 176 cases (0.2 cases per 10 000 people)

6. India Brazil Indonesia

7. In mid 2003, Nepal with overall leprosy prevalence rate of 3.04/10000 ranked 4th globally. But the GoN undertook the initiative to decrease it below 1 per 10,000 population and finally succeeded in 2010. Current prevalence is below 1/10000 and now major target for 2020 is to reduce grade II disability below 1 per million populations

8. Agent Factors Agent: Mycobacterium Leprae acid-fast and occur in the human host both intracellularly and extracellularly . Numerous antigens (more than 20) have been detected in M. leprae , some of these are shared by those of pathogenic and non-pathogenic mycobacteria, e.g.. BCG, M . smegmatis , M. tuberculosis M. Ieprae has not yet been conclusively shown to grow inartificial medium which is why progress in research has lagged behind than that of many other diseases.

9. SOURCE OF INFECTION Currently all patients with "active leprosy" are considered infectious. Recently new evidence has surfaced that natural infections with M. Ieprae are present in wild animals like armadillos and chimpanzees though it is not yet known if leprosy in wild animals is a threat to public health. PORTAL OF EXIT Lepromatous cases harbour millions of M. Ieprae in their nasal mucosa which are discharged when they sneeze or blow the nose. ulcerated or broken skin of bacteriological + ve cases

10. INFECTIVITY highly infectious disease with low pathogenicity ATTACK RATES among household contacts of lepromatous cases, 4.4% to 12% -in expected to show signs of leprosy within 5 years.

11. Host factors lncidence rates generally rise to a peak between 10 and 20 years of age and then fall A high prevalence of infection among children means that the disease is active and spreading. incidence and prevalence of leprosy appear to be higher in males than in females in most regions of the world probably due to their greater mobility and increased opportunities for contact in many populations.

12. only a few persons exposed to infection develop the disease. A large proportion of early lesions that occur in leprosy heal spontaneously. C ell-mediated immunity (CMI) is responsible for resistance to infection with M. leprae , ln lepromatous leprosy and there is a complete breakdown of CMI; in these cases the lepromin test is negative

13. Environmental factors the presence of infectious cases in that environment. overcrowding and lack of ventilation within households have been implicated in transmission of Leprosy. There is evidence that humidity favours the survival of M. Ieprae in the environment

14. Social pathology Leprosy is called social disease Social factors are poverty, poor housing, overcrowding, lack of education, lack of personal hygiene … Fear, Guilt & unfounded prejudices…… Social stigma is due to “deformity” Social ostracism – Hide infection & delay in treatment ---- affect the control program Psychological factors

15. Modes of transmission leprosy may be transmitted v ia aerosols containing M. leprae (droplet infection) supported by the fact that: Inability of the organisms to be found on the surface of the skin demonstration of a large number oforganisms in nasal discharge the high proportion of intact bacilli in the nasal secretions Ieprosy is transmitted from person-to-person by close contact between an infectious patient and a healthy but susceptible person

16. Incubation period Range 9 months to 20 years Average: 4 years tuberculoid leprosy 8 years lepromatous cases

17. Signs and Symptoms Early signs and symptoms of leprosy are very subtle and occur slowly (usually over years). First symptoms : Numbness and loss of temperature sensation (cannot sense very hot or cold temperatures) As the disease progresses : The sensations of touch, then pain, and eventually deep pressure are decreased or lost. 17

18. Long-term developing sequence of events : Relatively painless ulcers, skin lesions of hypopigmented macules (flat, pale areas of skin), and eye damage (dryness, reduced blinking) Late stage: large ulcerations, loss of digits, and facial disfigurement . (for example, hands, feet, face, and knees). 18

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20. Leprosy - It is characterized by one or more of the following cardinal features :- Hypopigmented patches Partial or total loss of cutaneous sensation in the affected areas Presence of thickened Nerve. Presence of acid-fast bacilli in the skin or nasal smear.

21. Signs of advanced disease : Presence of Nodules or Lumps in the skin of the face & ears Plantar ulcers Loss of fingers or toes Nasal Depression Foot Drop & others. Leprosy….

22. Classification Ridley & Jopling Classification Based on Host Immunity TT BL LL BT BB BL 22 Other Classifications Indian: T,B,L, Pure neuritic Madrid: Indeterminate, T,B,L

23. Classification WHO Classification Based on Bacterial Load Paucibacillary 1-5 skin lesions Multibacillary >6 skin lesions Slit Skin Smear Positive Negative 23 Indeterminate Leprosy (IL) Tuberculoid Leprosy (TL) Borderline Tuberculoid (BT) Borderline Borderline (BB) Borderline Lepromatous (BL) Lepromatous Leprosy (LL) BI≥2 BI<2

24. Diagnosis Clinical Examination Bacteriological Examination: skin smears, Nasal blows/smears & scrapping's Foot pad culture: only certain way to identify M. leprae is to inoculate the material into the foot-pads of mice and demonstrate multiplication. Histamine Test: very reliable method for detecting peripheral nerve damage due to leprosy at an early stage. Biopsy

25. 6. Immunological Tests For detecting CMI Fernandez(early) Lepromin Test Mitsuda (late) The early reaction is induced by the soluble constituents of the leprosy bacilli; and the late reaction by the bacillary component of the antigen. It indicates cell-mediated immunity. LTT/LMIT For Humoral responses: FLA-ABS, Monoclonal antibodies, ELISA

26. Bacterial index (BI) indicates the density of leprosy bacilli in smears and includes both living (solid-staining) and dead (fragmented or granular) bacilli. only objective way of monitoring the benefit of treatment. - No bacilli in any of the 100 oil-immersion fields 1+ - 1-10 bacilli. on average, in 100 oil-immersion fields 2+ -10 bacilli on average, in 10 oil-immersion fields 3+ - 1-10 bacilli, on average, in each oil-immersion field 4+ - 10-100 bacilli, on average, in each oil-immersion field 5+ - 100-1000 bacilli, on average, in each oil-immersion field 6+ - More than 1000 bacilli on average, in each oil immersion field

27. Morphological index During microscopy examination it is possible to count the number of solid (completely) staining organisms and irregularly staining bacilli. widely believed that only solid-staining organisms are viable. The percentage of solid staining bacilli in a stained smear is referred to as morphological index (MI). This is an indicator of the patient's response to treatment with drugs, during the first few months and helps to signal drug resistance.

28. Leprosy Control The main principles of leprosy control is based on timely detection of new cases and their treatment with effective chemotherapy in the form of multidrug therapy and social support. The control Measures include: (A) Medical measures (B) Social support (C) Program management (D) Evaluation

29. ( A) Medical Measures -Estimation of the problem -Early case Detection -Records -Multi drug Therapy (MDT) prevalence a) Contact survey < 1 per 1000 pop n b) Group survey 1 per 1000 pop n or more c) Mass survey 1 per 1000 pop n Hyper endemic area

30. Objectives :- To interrupt transmission of the infection in the community by drugs To ensure early detection & treatment of cases to prevent deformities To prevent drug Resistance

31. Multibacillary : Ritampcin – 600 mg once monthly Dapsone – 100 mg Daily- self Clofamizine – 300 mg once monthly (supervised) - 50 mg daily – self - Clofamizine if unacceptable - Ethionamide or protionamide -250-375 mg daily – selfadministered Duration- one years

32. Paucibacillary : Ritampcin – 600 mg once monthly supervised Dapsone -100 mg daily- self Duration – six months Surveillance :- Paucibacillary –Examine once in a year for 2 years after completion of Rx Multibacillary :- once in a year for minimum of 5 yrs after completion of Rx. Leprosy……

33. Immunoproplyaxis : BCG has protective effect Uganda (80%), Myanmar (30%), India (23 %) Chemoprophylaxis:- For the contacts of Leprosy 1-4 mg/kg body wt - Dapsone - per week for child contacts – 35-53%, protection Given for 3 yrs or until the Index case becomes bacteriologically negative. Leprosy……

34. Deformities: - 25% pts. develop deformities. Gloves , foot wears etc. prevent deformities Rehabilitation : -Physical, Mental, Social & Vocational. Preventive Rehabilitation – preventing deformities Health Education : pt. & family – General public

35. B. Social support Socio- economic problem of the pt. should be identified & solved. Social stigma & support. C. Program Management Long term activity Proper planning & Management are essential D. Evaluation Operational Indicators : case finding & Rx Relapse & deformities Epidemiological Indicators :- Incidence & Prevalence.

36. Thank You January 27 - World Leprosy Day