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Flashcards in Opportunistic Infx Deck (44)
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1

list the 3 types of defects in the compromised host and give an example of each ?

1- defects or injury to physical barrier
ex- serious burns
2- deficiency in innate immunity
ex- reduced # or function of PMN (leukemia, chemotherapy, cong. immune def.)
3- deficiency in adaptive immunity
ex- t cells (HIV/AIDS) ; B cell and Ab (congen. immune def)

2

What organisms are the MCC of burn infections (4) which of these are on skin?

Pseudomonas, Staph aureus (skin), Strep (skin), Candida (skin)

3

Where is psuedomonas likely to grow within a hospital?

In moist/ wet areas : sinks etc,

4

In the case of a servere burn patient what factors increase risk of infection?

1- burn itself- loss of protective skin
2- severe burns decrease in PMN function
3- hospitalization- at risk for nosocomial infection

5

Where could aspergillus be found in a hospital?

potted plants (soil) , air ducts etc. transmitted to skin via spores

6

A serverely burned child has multiple nosocomial infections one of which is aspergillus- what is the preferred treatment and what are possible side effects

amphotericin - TOXIC TO KIDNEYS

7

list several possible drug treatments for a pseudomonas infection

extended spectrum PCN +/- beta-lactamase inhibitors; carbapenems, aztreonam, fluoroquinolones, ceftazidime, cefepime, aminoglycoside

8

what are ways a neonate can become infected with Listeria from the mother?

transplacental transmission
ascending infx through ruptured amniotic membranes
during birth through infx birth canal

9

what is the DOC for infant with Listeria infx?

Ampicillin + Gentamycin

10

what is the DOC for mother if showing sx of Listeria

Ampicillin

11

severe asthmatic patient dx with pneumonia. the origin is Nocardia sp. - what made this patient suceptible to this infx?

long term cortico steroid therapy !!!!

12

What are common sources of nocardia bacteria?

soil!

13

What are some KEY buzzwords/characteristics regarding Nocardia?

aerobic, G+ bacilli tends to form CHAINS OR FILAMENTS, weakly acid fast

14

What is the DOC for Nocardia infx?

TMP/SMX - folic acid inhibitor

15

Pt w/ h/o AIDS presents w/ fever, night sweats, fatigue, diarrhea past 3 mo. Dx Mycobacterium avium. GROWING IN MACROPHAGES-
A- how would it be killed?
B- where does it come from?

A- normally T cells will kill infx Macrophages
B- soil

16

When T cell count gets below 50 in AIDS pt what is DOC for Mycobacterium avium tx? CAN USE EVEN AS PREVENTION!

Macrolide + Ethambutol

17

What are some causes of neurologic signs in AIDS patient suspect???

AIDS dementia; Toxoplasmosis; EBV- B cell lymphoma; CMV; Coccidiodes/ Cryptococcus; JCV (polyoma virus)

18

AIDS pt c/o slow onset of progressive confusion/forgetful past 6 weeks; develops hemiparesis on one side of body. CSF fluid PCR dx JCV. What is the dz caused by this

PML - progressive multifocal leukoencephalopathy

19

What are sx of PML associated with JCV

slow onset of focal sx includes behavior/speech/cognitive behavior/motor/visual impairment; aphasia, hemiparesis, ataxia, cortical blindness,

20

how can you make a definitive dx of PML due to JCV

PCR of CSF sample

21

23 y/o AIDS pt develops fever, nuchal rigidity, severe HA - what is the MCC of meningitis in AIDS pt? What is one of the virulence factors associated with this organism

Crytococcus meningitis - CAPSULE

22

Where is Cryptococcus meningitis commonly found?

soil- bird droppings

23

What is missing in the immune response why AIDS pt gets cryptococcus

macrophage cant be activated bc T cell counts very low and if no T cells no IFN-gamma to activate Macrophage!

24

How would you diagnose cryptococcus ?

India Ink stain CSF- yeast w/ capsule
Confirm with growth on Sabouraud's agar, Heart Brain infusion agar

25

How would you treat cryptococcus in AIDS pt ?

Amphotericin B and flucytosine

26

AIDS pt from SE Missouri, presents w/ persistent high grade fever, weight loss, hepatosplenomegaly, mucocutaneous ulcers. You perform ELISA on serum and urine for antigen was +
A- Whats the source of infection?

HISTOPLASMA CAPSULATUM
A- spores inhaled

27

What would histoplasma infection look like on CXR in an immunocompetent pt

walled off (granulomas present)

28

What T cell is needed for granuloma formation/ chronic inflammation? what happens when a pt with granulomas develops AIDS

Th1 cells - no T cell response so dissemination

29

Who is at risk for H. capsulatum ? What would be the immunocompetent pt immune response?

ANYONE that is in MS river valley area/ frequently goes caving etc.
Th1 involved/ Macrophage involved in forming granuloma wall the infection off

30

What is the DOC/tx for H. capsulatum ?

Amphotericin B +/- azole