lecture 7- infectious diseases Flashcards
(27 cards)
tuberculosis is caused by what bacterium?
mycobacterium tuberculosis in lungs and mycobacterium bovis in gut
traits of primary tuberculosis infection
- 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
secondary TB infection
reactivation of TB from opened neurotic scar tissue pockets of lungs
most common secondary TB manifestation
pulmonary TB
how rare is skeletal TB infection?
very rare, <5% of cases
in skeletal TB, where do tubercle bacilli congregate?
Red marrow of axial skeleton, cranium, and in infants/children pedal and manual elements
how is Skeletal TB observable on the bones?
- 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
what percentage of skeletal TB affects the joints and causes TB arthritis?
90%
tuberculosis spondylitis is also known as what?
Potts disease
what percentage of skeletal lesions affect the vertebrae?
<40%
what is tuberculosis coxitis?
tuberculosis infection of the os coxae and hip
tuberculosis coxitis effects
- 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.
what is tuberculosis dactylitis?
tuberculosis infection of the phalanges that causes necrosis of cortex and involucrum with occasional digit shortening
does tuberculosis affect the cranium?
yes but rarely. mostly affects children with vault first and then face
what is brucellosis?
one of several known zoonoses that manifests itself as a chronic infection of lungs with recurring fever
what parts of skeleton does brucellosis commonly affect?
spine and sacroilliac area
leprosy is caused by what?
mycobacterium leprae
what is leprosy?
a granulomatous infection with highly varied manifestations
what is tuberculoid leprosy?
lesions on skin and cutaneous nerves
what is lepromatous leprosy?
widespread lesions affecting many body systems
what does leprosy effect?
mainly tissues and skin but 5% of cases affect skeleton. bones of face, hands, and feet
how many bony responses are there to leprosy?
3
what are the three bony responses to leprosy?
1) lepromatous osteomyelitis and periostitis, 2) neurotrophic bone and joint lesions, 3) secondary osteomyelitis and septic arthritis
how many clinically distinct syndromes of treponematoses infection are there? how many affect the skeleton?
- 4.
