LEPROSY Flashcards
TRUE OR FALSE: M. leprae is an obligate, intracellular, acid-fast staining, rod-shaped bacterium
TRUE
It is the measure of uniformly stained solid bacilli on slit-skin smear examination and is calculated as the percentage of viable bacilli among the total number of bacilli counted under oil-immersion microscopy
morphologic index
It is a logarithmic-scaled measure of the density of bacilli of all forms found in the dermis upon slit skin smear examination, varying from 0 to 6+ (with or without globi) from the tuberculoid to the lepromatous end of the disease spectrum.
bacteriologic index
M. leprae infects mainly what cells?
macrophages and Schwann cells
What is the definition of leprosy elimination according to the WHO?
prevalence of <1 case per 10,000 population at the global level
Mode of transmission of M. leprae
Can be shed in large numbers from the mouth and nose of patients with untreated multibacillary leprosy (droplet infection) and sometimes from damaged skin
Main reservoir of M. leprae
HUMANS are the main reservoir of infection for M. leprae
- Armadillo is also a reservoir for human infection
Incubation period of M. leprae
2 years to 10 years
- Incubation period for multibacillary leprosy appears to be longer (5 to ≥10 years) than that for paucibacillary leprosy (~2–5 years)
The most important risk factors for the transmission of leprosy?
Intimacy and duration of contact with a leprosy patient
*in particular with an index case with multibacillary leprosy, and the intensity of contact with and physical distance from the index patient
According to the WHO leprosy classification, this is defined as one to five skin lesions and no or only one involved peripheral nerve
Paucibacillary leprosy
According to the WHO leprosy classification, this is defined as six or more skin lesions and/or more than one involved peripheral nerve.
Multibacillary leprosy
This type of leprosy is characterized by either a well-defined, hypopigmented macule or a raised, erythematous/ brown/copper-colored plaque with a well-defined edge on any part of the skin with complete loss of fine touch and temperature sensations over their surface. On slit-skin smear examination, no acid-fast bacilli (AFB) are normally found. The lepromin skin test is strongly positive, signifying good host CMI status.
Tuberculoid leprosy
This type of leprosy has innumerable bilateral, symmetrically distributed, diffusely indurated, erythematous, copper-colored, or skin-colored patches or plaques. There is no loss of sensation over these lesions, which have a smooth, shiny surface. The lesions are spread over the face, earlobes, ears, extensor aspects of the upper and lower extremities, back, and buttocks. Slit-skin smear examination shows a bacteriologic index of 4+ to 6+ with globi
Lepromatous Leprosy
It is an immunologic phenomena that occur before, during, or after treatment. In addition, it has severe complications that need to be diagnosed and treated early to prevent nerve function impairment
Leprosy reactions
This is a delayed hypersensitivity reaction associated with sudden alteration of CMI status and leading to a shift in the patient’s position on the leprosy spectrum. Also known as reversal reaction
Type 1 Leprosy reaction