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Flashcards in TB 1 Deck (19)
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1

what organism causes tuberculosis

mycobacterium tuberculosis

2

what is meant by latent TB disease

infected but asymptomatic; disease is not active

3

what makes something considered multidrug resistant TB

TB resistant to at least 2 preferred anti-TB drugs

4

what countries are at high risk for TB

mexico
philipines
Vietnam
india
china

5

what age is most commonly affected by TB

25-44

6

what are the risk factors for TB

1. age: 25-44
2. low SES
3. non-caucasion
4. prolonged contact with infected
5. HIV (most important risk factor)

7

what are the caracteristics of mycobacterium tuberculosis?

gram positive aerobic with unusual waxy coating

8

what immune system response is essential to controlling M. tuberculosis infections

T-lymphocytes

9

what are the primary T cells involved in immune response to TB

CD4+ (a type of T-lymphocyte)

10

what are the 3 factors that contribute to TB disease progression

1. amount of M. TB organisms inhaled
2. virulence of the organisms
3. host's cell-mediated immune response

11

if someone has latent disease, will they test positive on skin test? how long can they remain latent

yes, will test positive
may be latent for the rest of there lives

12

how does active infection occur from a latent infection

immune system fails to wall off infection during the primary infection

13

when is the highest risk of going from latent to active

2 years after infection

14

what are the 4 screening guidelines for TB screening

1. emigration within 5 years from high prevalence countries
2. Immunosuppressed patients
3. close contacts of people with active TB
4. those with evidence of recent TB infection

15

what are 4 downfalls of PPD skin test

1. booster effect
2. prior BCG vaccination can mess up results
3. requires multiple visits to conduct test
4. subjective interpretation

16

PPD measures presence of cellular immunity by assessing what

delayed-type hypersensitivity

17

what blood test can be done for TB

quantiferon gold (gold standard)
T-SPOT

18

what do blood tests for TB look for

interferon-gamma release

19

what are 4 advantages to blood tests for TB over skin tests

1. provides quick and specific results
2. no booster effect
3. prior BCG does not effect results
4. lab based assay - unbiased interpretation