lecture 7- infectious diseases

Question 1

tuberculosis is caused by what bacterium?

Answer 1

mycobacterium tuberculosis in lungs and mycobacterium bovis in gut

Question 2

traits of primary tuberculosis infection

Answer 2

• waxy coat of maycobacterium causes it to survive microphage digestion
• T lymphocytes destroy infected “microphages” and destroyed tissue
• area of necrosis is walled off by scar tissue
• sometimes area of scar tissue is large enough for tubercle bacilli to survive
• opening of ST causes reinfection and secondary symptoms

Question 3

secondary TB infection

Answer 3

reactivation of TB from opened neurotic scar tissue pockets of lungs

Question 4

most common secondary TB manifestation

Answer 4

pulmonary TB

Question 5

how rare is skeletal TB infection?

Answer 5

very rare, <5% of cases

Question 6

in skeletal TB, where do tubercle bacilli congregate?

Answer 6

Red marrow of axial skeleton, cranium, and in infants/children pedal and manual elements

Question 7

how is Skeletal TB observable on the bones?

Answer 7

• local lytic destruction of trabecular bone, with little to no sclerotic bone formation
• no or limited periosteal bone formation
• sequestration of cortex and formation of involucrum

Question 8

what percentage of skeletal TB affects the joints and causes TB arthritis?

Answer 8

90%

Question 9

tuberculosis spondylitis is also known as what?

Answer 9

Potts disease

Question 10

what percentage of skeletal lesions affect the vertebrae?

Answer 10

<40%

Question 11

what is tuberculosis coxitis?

Answer 11

tuberculosis infection of the os coxae and hip

Question 12

tuberculosis coxitis effects

Answer 12

• focal destruction resulting in superior or medial dislocation of caput and destruction of femoral head
• destruction of acetabulum
• affects sacroilliac joint, illium, pubis, and ishium rarely.

Question 13

what is tuberculosis dactylitis?

Answer 13

tuberculosis infection of the phalanges that causes necrosis of cortex and involucrum with occasional digit shortening

Question 14

does tuberculosis affect the cranium?

Answer 14

yes but rarely. mostly affects children with vault first and then face

Question 15

what is brucellosis?

Answer 15

one of several known zoonoses that manifests itself as a chronic infection of lungs with recurring fever

Question 16

what parts of skeleton does brucellosis commonly affect?

Answer 16

spine and sacroilliac area

Question 17

leprosy is caused by what?

Answer 17

mycobacterium leprae

Question 18

what is leprosy?

Answer 18

a granulomatous infection with highly varied manifestations

Question 19

what is tuberculoid leprosy?

Answer 19

lesions on skin and cutaneous nerves

Question 20

what is lepromatous leprosy?

Answer 20

widespread lesions affecting many body systems

Question 21

what does leprosy effect?

Answer 21

mainly tissues and skin but 5% of cases affect skeleton. bones of face, hands, and feet

Question 22

how many bony responses are there to leprosy?

Answer 22

3

Question 23

what are the three bony responses to leprosy?

Answer 23

1) lepromatous osteomyelitis and periostitis, 2) neurotrophic bone and joint lesions, 3) secondary osteomyelitis and septic arthritis

Question 24

how many clinically distinct syndromes of treponematoses infection are there? how many affect the skeleton?

Answer 24

5. 4.

Question 25

what are the 4 syndromes of treponematosis that affect the skeleton?

Answer 25

acquired syphilis, congenital syphilis, yaws, bejel

Question 26

how many phases of acquired syphilis?

Answer 26

3. primary phase, secondary phase, tertiary phase

Question 27

how does acquired syphilis affect skeleton?

Answer 27

Cranium: nasal pitting and deformation, “saddle nose”