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Flashcards in MTB Deck (56)
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1
Q

gram stain morphology of MTB?

A

acid fast

2
Q

describe the cell wall of MTB?

A

gram negative cell wall

stains acid fast

3
Q

what are the key virulence factors of MTB?

A
mycolic acids (cause acid fast)
trehalos mimycolate (cord factor)
4
Q

what are the growth requirement for MTB?

A

facultative intracellular of macrophages

5
Q

what are the oxygen growth requirements for MTB?

A

obligate aerobe

6
Q

how long does it take to culture MTB?

A

2-3 weeks

7
Q

what is MTB sensitive to?

A
UV light
moist heat (pasteurization)
8
Q

what is the transmission for MTB?

A

from person with pulmonary or laryngeal TB via inhalation of airborne droplets

9
Q

is MTB highly contagious?

A

no, not highly contagious

10
Q

what is the reservoir for MTB?

A

humans

11
Q

what age group is most susceptible for MTB infection?

A

children <4 yo immunocompetent

12
Q

what age group is most susceptible for reactivation of pulmonary TB?

A

elderly >65 yo

13
Q

what percent of MTB patients remain LTBI for life?

A

90%

14
Q

what groups are particularly high risk for MTB infx?

A

foreign
poor
HCW

15
Q

what groups are high risk for TB after MTB infx?

A

young, old
CMI compromise
HIV
IVDU

16
Q

what are common seeding sites for MTB?

A

apical-posterior areas of lung

lymph nodes

17
Q

does MTB produce toxins?

A

no, tissue damage is caused by CMI

18
Q

what causes caseation necrosis (soft tubercles) in MTB infx?

A

granuloma formation

19
Q

is a granuloma evident in CXR?

A

no, only in tissue biopsy

20
Q

how does LTBI progress to TB?

A

weak CMI allows dormant MTB in tubercles to reseed the body

21
Q

what causes primary pulmonary TB?

A

weak immune response, fails to localize primary infx

22
Q

what causes reactivation pulmonary TB?

A

systemic immunosuppression (HIV, old age)

-most common form of TB in US

23
Q

what differentiates extrapulmonary TB?

A

involves any other organ system

24
Q

what is miliary TB?

A

massive disseminated infx involving multiple organs

25
Q

what is the key clinical factors in reactivation TB?

A
  • air-liquid filled cavities

- hemoptysis, caseium release

26
Q

are there any symptoms of LTBI?

A

no, asymptomatic

27
Q

how is LTBI proven?

A
  • positive PPD test

- positive quantiferon test

28
Q

if S/S of TB are present, then what kind of TB is going on?

A

fuckin TB, of course

29
Q

how far along is the disease if S/S of TB are noted?

A

pretty fucking far along, d/t slow growth rate of pathogen

30
Q

what are some fucking buzz words for TB?

A

slow, insidious onset/progression
flu like symptoms
anorexia w/ weight loss (fucking redundant)

31
Q

what are some stupid-ass, barely-usable buzz words for TB?

A

chronic, persistant cough
pleuritic pain
dyspnea

32
Q

who’s not as fucked as a TB pt, but still pretty god damn fucked?

A

close contacts d/t slow onset of symptoms. the dude’s been infectious for a while so there’s a pretty good chance they have an infx (but not necessarily a disease)

33
Q

what type of pulmonary lesions are usually seen with HIV patients who get MTB?

A

diffuse pulmonary infiltrates d/t poor CMI response

-therefore, coin-like lesions aren’t common

(jeez, how fuckin bad do you have to treat your body that you can’t even get sick right…fuck)

34
Q

can a PPD or quantiferon test differentiate between TB and LTBI?

A

nope, of course not, that would be too easy

35
Q

is a negative PPD skin test a guaranteed rule out for TB?

A

no, 20% of MTB infx don’t show positive PPD tests

once again, that would be too fuckin easy

36
Q

when does a patient seroconvert in order to give a positive PPD test?

A

3-8 weeks after primary infx

37
Q

what is the minimum PPD measurement for normal people?

A

> 15 mm

38
Q

what is the minimum PPD measurement for other assholes?

A

> 10 mm

39
Q

what is the minimum PPD measurement for people stupid enough to get HIV or live with TB pts?

A

> 5 mm

40
Q

what vaccination can cause false positives in PPD test?

A

BCG vaccination

41
Q

why is quantiferon gold test better than PPD?

A

basically shits all over PPD’s potential for false negatives, particularly for HCW’s

-damn, I gotta get the quantiferon test next time. fuck this 3 visit BS

42
Q

do you have to report TB to local health department?

A

yeah, shit head, it’s a super infectious disease

43
Q

if you find a single, solitary pulmonary nodule “by chance” in an asymptomatic patient, what’s your DDx?

A
MTB
Nocardia
Actinomyces
systemic mycoses
lung cancer
hamartoma/adenochondroma
44
Q

what’s the first lab indicator of MTB?

A

acid fast bacilli in sputum

45
Q

what else besides sputum culture is needed when MTB is suspected?

A

blood cultures to see if MTB is tearing shit up around the body (hematogenous dissemination)

46
Q

what the fuck is nucleic acid amplification (NAA) testing?

A

don’t care, but it’s quicker than culture

47
Q

what are first line MTB drugs?

A

isoniazid
rifampin
pyrazinamide
ethambutol

48
Q

what is MDR in MTB?

A

doesn’t respond to:

rifampin
INH

49
Q

what is XDR MTB resistant to?

A

rifampin
INH
fluoroquinolones

and basically every other fucking drug ever

50
Q

what’s the general treatment for LTBI?

A

INH for sick bastard

rifampin for close contacts (and pussies who can’t handle INH)

51
Q

what is the general treatment for drug senstive TB disease?

A

isoniazid 18 months

isoniazid + rifampin 9 months

52
Q

what is the general treatment for drug resistant TB disease?

A

chemo
resistant: shit load of drugs
MDR: fuck ton of drugs (more than shit load)

53
Q

treatment for XDR MTB?

A

cut that shit out

54
Q

when is treatment started?

A

only after Dx confirmed. that shit sucks too much to start needlessly

55
Q

how is spread of TB prevented?

A

cover your fucking mouth when you cough/sneeze. fucking sick fucks, I swear

56
Q

is BCG used in US?

A

nope