LEPROSY
Definition: Chronic granulomatous infectious disease of skin
& peripheral nerves, Caused by Mycobacterium Leprae, also known as Hansen’s disease. Skin, muscles,
eyes, bones, testes and internal organs can also be involved.
Etiopathogenesis Causative organism Mycobacterium Leprae is a weak acid fast obligate intracellular bacilli. Discovered by Gerhard Heunk Armauer Hansen in 1873 in Norway.
Can be grown in foot pad of mice & nine banded Armadillos.
Very low infectivity even Conjugal partners have 5% risk of transmission of disease.
Etiopathogenesis Causative organism Mycobacterium Leprae is a weak acid fast obligate intracellular bacilli. Discovered by Gerhard Heunk Armauer Hansen in 1873 in Norway.
Can be grown in foot pad of mice & nine banded Armadillos.
Very low infectivity even Conjugal partners have 5% risk of transmission of disease.
genetic susceptibility is also seen
Risk of children acquiring infection from infected adults in the family is 60%.
Risk of children acquiring infection from infected adults in the family is 60%.
• Transmission: Still uncertain but most likely, spread s via droplet mode, from untreated patients nasal mucosa, other routes can be skin to skin or may be via GIT.
• Generation time is 12 days, Incubation period is 2—7 yrs. (average 3-5 yrs)
• The optimal temperature for growth for leprae bacilli is 30 - 33 centigrade
• Virulence factor of M. Leprae is phenolic glycolipid I, a surface lipid, specific to this bacillus.
• Common sites which are involved — Skin, Peripheral Nerve, generally involves every organ except CNS & Ovaries and lungs.
• M. Leprae attacks Schwann cells of peripheral nerves, unmyelinated are more affected.
• Tuberculoid leprosy is the one end of spectrum of disease, is seen in high resistance person
• Lepromatous leprosy is the other end of spectrum of disease, seen in low resistance person.
• Transplacental Infection does not occur
• In India, tuberculoid leprosy is more common as compared to Lepromatous Leprosy.
Some
general facts about leprosy ace:
• Cell mediated immune response of the host determine the type of leprosy.
• TT and LL patients are stable
• TT leprosy often self heals, most common type of leprosy in India.
• First clinical symptom in leprosy is numbness. .
• LL leprosy remains heavily infected unless given appropriate chemotherapy.
• BR leprosy is the most unstable, with most patients down grading if not treated
• Leprosy can affect all ages and both sexes.
• The limited growth of M. leprae in the mouse foot pad provided a way to screen for therapeutic agents and to identify drug resistance in leprosy.
• The recognition of leprosy in the nine banded armadillo provided a source of large quantities of highly
purified M leprae for biochemical anti immunologic studies including preparation of vaccine for leprosy
• Cell mediated immune response of the host determine the type of leprosy.
• TT and LL patients are stable
• TT leprosy often self heals, most common type of leprosy in India.
• First clinical symptom in leprosy is numbness. .
• LL leprosy remains heavily infected unless given appropriate chemotherapy.
• BR leprosy is the most unstable, with most patients down grading if not treated
• Leprosy can affect all ages and both sexes.
• The limited growth of M. leprae in the mouse foot pad provided a way to screen for therapeutic agents and to identify drug resistance in leprosy.
• The recognition of leprosy in the nine banded armadillo provided a source of large quantities of highly
purified M leprae for biochemical anti immunologic studies including preparation of vaccine for leprosy
