Micro: Leprosy

Question 1

Bug that causes leprosy

Answer 1

Mycobacterium leprae

Question 2

Other name for leprosy

Answer 2

Hansen’s disease

Question 3

Which tissues are affected by leprosy?

Answer 3

Peripheral nerves, superficial tissues, esp. nasal mucosa

Question 4

How do you culture M. leprae in the lab?

Answer 4

Trick question. You can’t culture it. Have to culture it on armadillos.

Question 5

What are the two types of leprosy?

Answer 5

Tuberculoid and lepromatous

Question 6

What are the differences between tuberculoid and lepromatous leprosy?

Answer 6

Tuberculoid: non-contagious, self limiting, causes lesions on face, limbs, butt. Can cause anesthesia in peripheral nerves (not facial). Low numbers of bugs present in lesions. Good prognosis.

Lepromatous: Lesions more extensive, notable on earlobes. Causes more tissue destruction (collapse of nasal septum, loss of digits, atrophy of testicles). Contagious. Lacks Th1 mediators. Bug spreads to reticuloendothelial system.

Question 7

How do you treat leprosy?

Answer 7

Many drugs for a long time (mycobacterium)

Question 8

How is leprosy spread?

Answer 8

Via small droplets from nasal secretions of lepromatous leprosy patients

Question 9

How infective is leprosy?

Answer 9

It’s infectivity is low. spread requires prolonged close contact with an infected person. Incubation period may be 2-7 years.

Question 10

Where does the bug live in the body?

Answer 10

Intracellular in macrophages and Schwann cells.