1Disease Classification
Leprosy- Hansen’s Disease
2Causative Organism
Myobacterium leprae
3GTKYCA
GPR, Acid-fast, Aerobic, 11-13 day doubling time, can’t be easily cultured, obligate intracellular parasite, invades schwann cells associated with peripheral neurons
4Epidemiology: Reservoir
Armadillos, Humans
5Epidemiology: POE
Skin, Mucosa, Upper Respiratory Tract
6Epidemiology: MOT
(ALL likely) Respiratory droplets, direct skin contact, zoonotic
7Incubation Period
3 months- 20 yrs
8Pathogenesis
Bacteria infect skin cells macrophages and peripheral nerves of cooler extremitis. Immune responses can result in tubercle formation and/or tissue damage or loss- including nerve damage and loss of sensory perception. Tissue damage results from non-inflammatory cell death
9Symptoms
Asymptomatic; Incubation 5 yr average; Skin lesions, Numbness, Painless ulcers
10Skin lesions apperance
hypopigmented, raised flat red patches, dry, scaley, reversal reactions (plaques with a red border)
11Complications
Nerve damage, paralysis, deformitis such as clawed hand, tissue necrosis, corneal ulcers, bone loss (digit resorption), infertility
12Prevention
Avoid contacting infected animals, tuberculosis (BCG) vaccine (possibly 32-86% effective)
13Treatment
Multiple Antibiotic Therapy (6-12 month); rifampin, dapsone, clofazimine