Professor Shagufta Hussain MYCOBACTERIUM LEPRAE Professor Shagufta Hussain

SPECIES OF MYCOBACTERIUM Mycobacterium leprae ---------leprosy. Mycobacterium tuberculosis --tuberculosis Mycobacterium bovis---------- tuberculosis Mycobacterium africanum----- tuberculosis TB complex Atypical mycobacteria(MOTT) (opportunistic) more than 50 Mycobacterium species, including many that are saprophytes

LEPROSY Chronic Infectious Disease affecting Skin Peripheral nerves Mucosa of upper respiratory tract Eyes mucosa

Global Leprosy Situation 1998  

MORE INTERESTING FACTS: In the 1940’s having leprosy was considered a criminal offense People with leprosy could be hunted down and shipped off to remote islands where they could spend the rest of their lives in solitude At one point, Patients in Kalawao,Hawaii who were about to be shipped off could request a re-diagnosis It turned out that ten out of eleven people who requested a re-diagnosis did not have leprosy after all

Ziehl-Neelsen stain - II Less acid-fast than TB 5% sulphuric acid fast not to 25%

Mycobacterium leprae leprosy Described by Hansen in 1873 9 years before Koch's discovery of the tubercle bacillus more than 10 million cases of leprosy, mainly in Asia. Not cultivated on nonliving bacteriologic media. Typical acid-fast bacilli—singly, in parallel bundles, or in globular masses

Mycobacterium leprae leprosy Slow growing 14 days Armadillos reservoirs in USA only Intracellular multiplication in skin histiocytes ,endothelial cells & schawann cells

Two major types Lepromatous Tuberculoid With several intermediate stages.

TUBERCULOID TYPE LEPROMATOUS TYPE Course benign non progressive macular skin lesions severe asymmetric sudden onset nerve involvement Few bacilli present in lesions Anemia,lymphadenopathy Eye involved & Amyloidosis. Cell-mediated immunity intact and skin infiltrated with helper T cells. Positive lepromin skin test. Course malign progressive nodular skin lesions slow symmetric nerve involvement Abundant t bacilli in lesions Continuous bacteremia Cell-mediated immunity is markedly deficient and skin infiltrated with suppressor T cells Negative lepromin skin test

EPIDEMIOLOGY Transmission occur when small children are exposed for prolonged periods to heavy shedders of bacilli. Nasal secretions likely infectious material for family contacts. incubation period 2–10 years. Without prophylaxis 10% of exposed children may acquire the disease. Treatment reduces and abolish infectivity of patients Naturally infected armadillos in Texas and Mexico play no role in transmission to humans.

Clinical Findings Insidious. lesions in cooler tissue of the body: skin, superficial nerves, nose, pharynx, larynx, eyes, and testicles macular skin lesions pale, anesthetic 1–10 cm in diameter; nodules diffuse or discrete erythematous, infiltrated 1–5 cm in diameter; diffuse skin infiltration leonine facies.

NEUROLOGIC DISTURBANCES Nerve infiltration and thickening, causes anesthesia, neuritis, paresthesia, trophic ulcers, bone resorption and shortening of digits. Never damage due to direct inflitration and CMI Disfigurement due to skin infiltration and nerve involvement in untreated cases may be extreme.

FLOW CHART FOR DIAGNOSIS AND CLASSIFICATION

DIAGNOSIS Scrapings from skin or nasal mucosa Biopsy of earlobe skin smeared on slide. Stained by the Ziehl-Neelsen 11 Biopsy of skin or of a thickened nerve gives a typical histologic picture. No serologic tests are of value. Non treponemal serologic tests for syphilis frequently yield false-positive results in leprosy.

Diagnosis bacilli within the endothelial cells of blood vessels or mononuclear cells When bacilli inoculated into footpads of mice, local granulomatous lesions develop with limited multiplication of bacilli. Inoculated armadillos develop extensive lepromatous leprosy, and armadillos naturally infected with leprosy have been found in Texas and Mexico. contains a unique o-diphenoloxidase, enzyme

ARMEDILLO

TREATMENT Sulfones e.g Dapsones are first-line therapy for both tuberculoid and lepromatous leprosy. Rifampin or clofazimine generally included in initial regimens due to resistance Other drugs minocycline, clarithromycin, and some fluoroquinolones 2 years of therapy or till lesions free of organism

Multi Drug Therapy

TREATMENT In LL treatment causes ERYTHEMA NODOSUM LEPROSUM Sign of CMI RESTORATION

PREVENTION Isolation of Lepromatous cases Chemoprophylaxis of exposed children with Dapsone No vaccine

MORE FACTS ABOUT LEPROSY Four leprosy vaccines currently in trail 1)BCG –34.1% PROTECTION 2)BCG+KILLED M.LEPRAE – 64.0% 3)M.W – 25.7% 4)ICRC – 65.5% 7 controlled trails and 9 case –control studies evaluating BCG in prevention of leprosy carried out in world

Thank you for your patience