Leprosy Flashcards
What is Leprosy and what does it affect?
A chronic granulomatous disease that affects peripheral nerves and superficial tissues (nasal mucosa)
What is the causative agent of Leprosy?
M. Leprae
How does M. Leprae differ from M. Tuberculosis?
It cannot be grown on agar media or in cell culture
What is the host of M. Leprae?
Humans, and armadillos
What are the two major forms of leprosy?
Tuberculoid and lepromatous
How is Leprosy transmitted?
Small droplets of nasal secretions from leprosy patients, infectivity is low
What is the incubation of Leprosy?
2-7 years; contraction requires close contact with an infected person
What area of the world do new infections arise?
India and Brazil
What is M. Leprae an obligate intracellular parasite of?
Macrophages and Schwann cells, can also invade peripheral neurons
What determines the extent of leprosy as a disease?
Degree of T-Cell mediated immunity; lepromatous cases lack TH1 mediators
What does the Tuberculoid Leprosy present with? Describe this version of the disease briefly
Single skin lesion on the face, limb, and buttocks; peripheral nerve involvement can leave lesions anesthetic; low numbers of organisms are in the lesion and the patient is usually not contagious, lesions can heal spontaneously and good prognosis
What does the Lepromatous leprosy present with? Describe it briefly
Progressive, first sign is edema and rhinitis; lesions are extensive on face, buttocks, and limbs; infiltration in ear lobes; drainage can be severe with perforation of nasal septum and collapse of nose; loss of fingers to neurotrophic atrophy; atrophy of testicles; spreads to RES
How is leprosy diagnosed?
Mostly clinical (can’t be grown in culture); confirm with skin biopsies and AFB’s
What is essential for treatment of leprosy?
Multi drug therapy (resistance is a problem)
What is the treatment of tuberculoid leprosy?
Sulfone (Para-aminobenzoic acid metabolism inhibitor) with Rifampin can cure tuberculoid leprosy with 6 months of treatment
