Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ICC1 > diagnosis of tuberculosis > Flashcards

diagnosis of tuberculosis Flashcards

1
Q

what is the diagnosis of pulmonary TB based upon ?

A

clinical
radiological
tuberculin testing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how many sputum samples are required for a diagnosis of TB

A

3 consecutive morning sample

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how is the detection of the intact bacilli done?

A

direct smear microscopy
culture and sensitivity
animal inoculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the types of direct smear microscopy ?

A

classical Ziehl Neelsen method

fluorescent method

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the causes of false positives smears ?

A

acid fast particles other than TB bacilli

  • food particles
  • precipitated stain
  • contamination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the cause of false negatives smear ?

A

inadequate sputum collection
inadequate sputum storage
inadequate stained smear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the different medias used in culture of mycobacterium ?

A

egg based - LJ medium
agar based
liquid based

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the problem with growing a culture ?

A

takes a long time 6-8 weeks do MGIT is now used

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how is the detection of metabolic end product of bacilli done?

A

radiometric technology ( middle brook 7H12 )
measures radio labelled CO2
positivee culturee is above 10 GI

mycobactins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how are the fragments of bacilli detected ?

A 
antigen 
tuberculo-stearicacid 
mycollic acid 
luciferin 
DNA or RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how would we detect mycobacterium using genetic probes (DNA, RNA) ?

A

NAAT-PCR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how can we detect drug resistance ?

A

we use PCR to identify drug resistance
INH resistance
rifampicin resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how can we detect the bacteria itself ?

A

either by detecting the intact bacillus itself
detecting fragments of the bacillus
or detecting metabolic end products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do we detect immune response ?

A

serology
lymphocyte activity markers ( ADA and gamma INF)
tuberculin skin test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the cut off value of ADA in the CSF?

A

cutoff value is 8 U/l differentiates TB meningitis from other causes of lymphocytic meningitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the cut off value of ADA in ascitic fluid ?

A

ADA above 36 U/L indicates possible TB

17
Q

what is the cut off value of ADA in pleural fluid ?

A
  • ADA level >70 U/l is highly suggestive of TB

- a level below 40 excludes a diagnosis

18
Q

where is ADA released from ?

A

lymphocytes

19
Q

if the ADA level in the pleura is between 40-70 what can we do to confirm a diagnosis of TB?

A

ADA ratio more than 2

20
Q

how is interferon gamma used to diagnose a case of TB?

A

a sample of blood with previously sensitized lymphocytes is taken, antigens are introduced to the sample and the amount of gamma interferon made by the lymphocytes are measured
NOT SHARED BY BCG

21
Q

What are the antigens thats are introduced to the blood sample in gamma interferon testing ?

A

ESAT6 and CFP10

CFP10

22
Q

what is the immunological basis for tuberculin reaction ?

A

kochs phenomenon

23
Q

what type of reaction happens with the tuberculin test ?

A

delayed hypersensitivity reaction

24
Q

what is injected in the tuberculin test ?

A

PPP tuberculin, 5 units of tuberculin , 0.1 mm intradermally injected

25
Q

how long does a result take to come out in a tuberculin skin test ?

A

48-72 hours later

26
Q

how is the reaction of the tuberculin test measured ?

A

by the induration , no induration ? 0mm

27
Q

what is the booster effect and what test is it positive in?

A

false positive with TST

28
Q

how to diagnose a latent TB infection ?

A

TST or IGRA assay

IGRA assays

29
Q

what is the medium used for the detection of metabollic end products ?

A

liquid middle brook 7H12

30
Q

what is measured in the radiometric technique ?

A

carbon dioxide levels as growth index

31
Q

what Growth index value indicates a positive culture ?

A

GI >10

32
Q

what mutation is associated with reifampcin resistyance ?

A

rpoB gene

33
Q

what are high level isoniazid resistance levels associated with ?

A

kat G gene

34
Q

what are low level isoniazid resistance associated with ?

A

inhA gene

ICC1 (50 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions