Presentation on theme: "Professor Shagufta Hussain"— Presentation transcript:
1 Professor Shagufta Hussain MYCOBACTERIUM LEPRAEProfessor Shagufta Hussain
2 SPECIES OF MYCOBACTERIUM Mycobacterium leprae leprosy.Mycobacterium tuberculosis --tuberculosisMycobacterium bovis tuberculosisMycobacterium africanum----- tuberculosisTB complexAtypical mycobacteria(MOTT) (opportunistic)more than 50 Mycobacterium species, including many that are saprophytes
5 MORE INTERESTING FACTS: In the 1940’s having leprosy was considered a criminal offensePeople with leprosy could be hunted down and shipped off to remote islands where they could spend the rest of their lives in solitudeAt one point, Patients in Kalawao,Hawaii who were about to be shipped off could request a re-diagnosisIt turned out that ten out of eleven people who requested a re-diagnosis did not have leprosy after all
6 Ziehl-Neelsen stain - II Less acid-fast than TB5% sulphuric acid fast not to 25%
7 Mycobacterium leprae leprosy Described by Hansen in 18739 years before Koch's discovery of the tubercle bacillusmore 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
8 Mycobacterium leprae leprosy Slow growing 14 daysArmadillos reservoirs in USA onlyIntracellular multiplication in skin histiocytes ,endothelial cells & schawann cells
9 Two major types Lepromatous Tuberculoid With several intermediate stages.
12 TUBERCULOID TYPE LEPROMATOUS TYPE Course benign non progressive macular skin lesionssevere asymmetric sudden onset nerve involvementFew bacilli present in lesionsAnemia,lymphadenopathyEye involved & Amyloidosis.Cell-mediated immunity intact and skin infiltrated with helper T cells.Positive lepromin skin test.Course malign progressivenodular skin lesionsslow symmetric nerve involvementAbundant t bacilli in lesionsContinuous bacteremiaCell-mediated immunity is markedly deficient and skin infiltrated with suppressor T cellsNegative lepromin skin test
13 EPIDEMIOLOGYTransmission 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 patientsNaturally infected armadillos in Texas and Mexico play no role in transmission to humans.
14 Clinical Findings Insidious. lesions in cooler tissue of the body: skin, superficial nerves, nose, pharynx, larynx, eyes, and testiclesmacular 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.
15 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 CMIDisfigurement due to skin infiltration and nerve involvement in untreated cases may be extreme.
17 DIAGNOSIS Scrapings from skin or nasal mucosa Biopsy of earlobe skin smeared on slide.Stained by the Ziehl-Neelsen 11Biopsy 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.
18 Diagnosisbacilli within the endothelial cells of blood vessels or mononuclear cellsWhen 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
20 TREATMENTSulfones e.g Dapsones are first-line therapy for both tuberculoid and lepromatous leprosy.Rifampin or clofazimine generally included in initial regimens due to resistanceOther drugs minocycline, clarithromycin, and some fluoroquinolones2 years of therapy or till lesions free of organism
22 TREATMENT In LL treatment causes ERYTHEMA NODOSUM LEPROSUM Sign of CMI RESTORATION
23 PREVENTION Isolation of Lepromatous cases Chemoprophylaxis of exposed children with DapsoneNo vaccine
24 MORE FACTS ABOUT LEPROSY Four leprosy vaccines currently in trail1)BCG –34.1% PROTECTION2)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