Brainscape's Knowledge GenomeTM

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


See full index

Pulmonology 2 > TB - clin med > Flashcards

TB - clin med Flashcards

1
Q

Where does TB occur

A
  • primarily in teh lungs

- also in other organ systems: lymphatics, bones, meninges, intestines, uterus/ovaries, etc.

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

TB Sx

A
  • productive, prolonged cough >3 weeks
  • chest pain
  • hemoptysis
  • low grade fever
  • night sweats
  • weight loss
  • excessive fatigue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what causes lung damage in TB

A

The body’s immune response to the bacteria, “spilling enzymes that eat teh lung tissue”, not the bacteria itself

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

Mycobacteria

  • how many species
  • how often pathogenic
  • how stain in lab
  • cell wall & significance
  • how common in environment
A
  • 150 species
  • most non-pathogenic
  • acid-fast stain
  • waxy cell wall means resistant to dehydration, harder to kill
  • very common in environment and normal flora
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is most common org to cause TB

A

mycobacterium tuberculosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

M. tuberculosis

  • what O2 conditions
  • fast/slow growing
  • cell wall
  • how big
A
  • obligate aerobe, requires high O2
  • very slow growing, 20 hour generation time
  • durable cell was, major factor in virulence
  • 2-4 microns in length
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many M. tuberculosis orgs required to show up as smear positive

A

10,000 orgs/ mL

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

What is the M. tuberculosis complex?

A

the types of mycobacteria that can cause TB. In OK only two ever seen:

  • M. tuberculosis (95%)
  • M. bovis (5%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a very common sputum test for TB

A

AFB - acid fast bacillus

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

When AFB is positive, what are the two main types of bacterial causes

A
  1. M. tuberculosis complex bacteria

2. non-tuberculous mycobacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

evolutionary hx of M. tuberculosis and M. bovis

A

ancient orgs that probably first appeared in the soil millions of years ago, gradually adapted to animal hosts

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

Who was the first scientist to ID TB

A

Robert Koch

  • 4 postulates demonstrating TB to be an infectious disease to Berlin Physiological Society in 1882
  • nobel prize for his work
  • proved contagious, not inherited
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the basic infectious particle of TB

A

droplet nuclei

  • aerosolized, dry rapidly and float
  • can float into alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does a person get TB

A
  • adequate exposure to viable orgs
  • prolonged contact in poorly ventilated space
  • not easy to acquire
  • cannot be transmitted outdoors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Once infected, what percentage of people progress to TB disease

A

10% over a lifetime

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

Once “get” TB, what happens with the bacteria

A
  • multiplication of bacilli in alveolar macrophages

- some spread to bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does the immune system do to bacilli when first contract the disease

A

usually prevents the disease by surrounding the bacilli with cells and creating granulomas resulting in latent TB infection (LTBI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

TB infection vs. disease

- what in common

A
  • mycobacteria causing TB present

- positive skin test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

TB infection vs. disease

- differences

A
  • Infection has normal CXR, lesions in disease
  • Sputum smear/culture negative in infection, positive in disease
  • no symptoms and not infectious in infection, yes to both in disease
  • not defined as a case of TB in infection, is defined as case of TB in disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Range of response to TB infection/disease

A
  • rapid killing of bacilli by alveolar macrophages = no infection
  • rapid progression of initial infection to death (usually <1 yo or immunocompromised)
  • and everything in between
    • can proceed with stops and starts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What affects the probability that someone who is exposed to TB will get TB

A
  • concentration of infectious droplet nuclei in the air

- duration of exposure to a person with infectious TB disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How to tell M. tuberculosis from M. bovis

A
  • cannot clinically, radiographically, or pathologically

- can differentiate via biochemical methods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is one major problem with M. bovis TB

A

universally resistant to one of the first line drugs (didn’t specific which one…)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Transmission of M. bovis TB

A
  1. contact through cuts, abrasions, etc.
  2. airborne (human to human, human to cattle, cattle to human)
  3. foodborne - onsumption of unpasteurized dairy products
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Who is at high risk for exposure to/infection with TB

A
  1. close contact with someone known or suspected to have TB
  2. foreign-born person from area where TB is common
  3. residents/employees of high-risk congregate settings (jail, prison, homeless shelter, etc.)
  4. health care workers who serve high-risk clients
  5. medically underserved, low-income
  6. high-risk racial or ethnic minority populations
  7. children exposed to adults in high-risk categories
  8. use illicit drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Two CDC classifications of TB applicable to PAs

A
  1. Class 2 - infection

2. Class 3 - active TB

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Treatment of latent TB

A
  1. Isoniazid for 9 or 6 months
  2. Rifampin with or without Isoniazid for 4 months
  3. Isoniazid and rifapentine for 3 months (1 X week)
28
Q

Treatment of inactive TB

A
  1. Isoniazid for 9 months
  2. Rifampin with or without Isoniazid for 4 months
  3. Rifampin and Pyrazinamide for 2 months
29
Q

What situations is TB disease more likely to develop

A
  1. infected contact of active case
  2. documented TB skin test converters
  3. have medical risk factors for disease reactivation
30
Q

HIV/TB co-infection

A
  • Risk is up to 37% in first year co-infected (vs. 10% with normal immune system)
  • risk of developing T disease 7 to 10% each year
31
Q

TB skin testing

A
  • old test that is often used incorrectly
  • report in millimeters of induration, disregard erythema
  • negative PPD does NOT rule out TB (15-20% active TB has negative PPD)
  • Anergy, a false negative reaction, can occur
32
Q

Two blood TB tests

A
  1. QuantiFERON-TB gold

2. T-spot.TB or ELISPOT

33
Q

Tx of TB prior to drugs

A
  1. bed rest
  2. sanitarium
  3. collapse therapy/thoracoplasty
34
Q

First line TB drugs

A
  1. isoniazid
  2. rifampin
  3. Rifapentine
  4. Rifabutin
  5. Ethambutal
  6. Pyrazinamide
35
Q

Second line TB drugs

A

LOTS

  • other abx
  • linezolid was singled out in class

*in general less effective, more side effects

36
Q

What is history of using multiple drug therapy to treat TB

A
  • 1940s tried using streptomycin alone but 40% developed resistance within 60 days
  • tried two drug therapy = fewer drug resistant bacteria
  • decided standard of therapy is multidrug
37
Q

List the four drugs used in active TB tx

A
  • Isoniazid
  • Rifampin
  • Pyrazinamide
  • Ethambutol
38
Q

When would extend treatment of active TB to 9 months (HIV negative person)

A
  • cavitation initially

- positive culture after 2 months of therapy

39
Q

what is MDR-TB

A

multidrug resistant TB

- INH and Rifampin

40
Q

what is Pre-XDR TB

A

pre-extensively drug resistant TB

- INH, rifampin resistance plus resistant to flouroquinolone OR injectable

41
Q

what is XDR-TB

A

Extensively drug resistant TB

- INH, rifampin, fluoroquinolone and at least one injectable resistance

42
Q

what is TDR-TB

A

Total drug resistant TB

43
Q

How long treat susceptible TB

A

6-9 months with 4 drugs for first 2 months

44
Q

How long treat MDR TB

A
  • first 8 months with 5 drugs (on injectable)
  • 20 months with 4 drugs
  • if prior treatment for MDR then 24+ months on 4 drugs
45
Q

How long treat Pre-XDR and XDR TB

A

24-36 months

46
Q

Who must go through mandatory TB screening?

A

immigrants and refugees

  • majority of air passengers are not these…
  • people with TB most often IDed after air travel
47
Q

how many cases have occurred due to exposure to someone on an airplane

A

None - evidence of transmission in one case but no disease

48
Q

How long must you be in contact with someone with TB to acquire infection?

A

> 8 hours exposure in close contact situations

49
Q

What is the vaccine many non-US people get for TB

A

Bacille Calmette-Guerin

(BCG) Vaccine

50
Q

What does BCG vaccine protect against? What does it not protect from

A
  • preventing severe TB in children

- does not prevent TB later in life

51
Q

What might cause a false-positive skin test reaction?

A
  1. non tuberculosis mycobacteria (usually =< 10 mm induration)
  2. BCG vaccination possible but not guaranteed (20%). Disregard BCG vaccination when applying and reading skin tests
  3. Reader error - don’t read erythema, just induration
52
Q

What test will be NOT be positive for TB due to BCG vaccine

A

Blood tests (IGRA or interferon gamma release assay)

53
Q

What is TB-PCR

A
  • Detects presence of MTB DNA directly from respiratory specimens
  • Not approved from non-respiratory specimens
  • high positive and negative predictive values with AFB smear positive
  • cheaper, not labor intensive
  • automatically performed on undiagnosed 1st time AFB positive clinical smears
54
Q

What is a surrogate marker for MDR-TB

A

Rifampin

90% will also be INH resistant

55
Q

What does molecular detection of drug resistant MDDR look for

A
  • to confirm rifampin resistance and not just a silent mutation in the DNA sequence
  • Looks for mutations in DNA for INH, ethambutol, PZA, fluroquinolones, etc.
56
Q

Is TB a disease we should be concerned about?

A
  • Yes! but not funded well by local and federal governments
  • deadliest dz in human history
  • kills more people in three days than died during entire ebola epidemic
57
Q

What is a very unusual way to test for TB that has been recently developed

A

African giant pouch rats
- 100 sputum in 20 minutes with near 100% accuracy

(just think of the pictures Kathleen haha)

58
Q

Legal TB Control

- what is required by law for TB cases

A
  1. compliance/isolation order
  2. Directly observed therapy (DOT)
  3. Noncompliance can result in court-ordered DOT
  4. noncompliance with DOT can lead to jail or confinement of pt until therapy is complete
59
Q

What are contraindications to PPD test

A
  • previous ulcer necrotic reaction

- true anaphylactic reaction to PPD in past

60
Q

What reaction can look like a positive PPD but is not

A

Arthus reaction - rapid type III rxn, redness and edema for 12-24 hours after injection. NOT a positive test

61
Q

What is a secondary location to place PPD for those with atrophic skin or who might scratch teh site

A

between shoulder blades

62
Q

What is two-step testing and why is it necessary

A
  • some people with latent TB might have a negative skin test years after infection due to waning response
  • The first test might stimulate the ability to react (boost)
  • a positive reaction with subsequent testing can be interpreted as a new infection rather than true old latent infection
63
Q

What is the name for two-step testing

A

boosting or anamnesis

anamnesis -forgetting to forget

64
Q

What is a main concern about dx TB today

A
  • failure to consider TB in the differential
  • lack of consistent and simple plan to address TB
  • “ER” mentality
  • lack of provider awareness of the necessity for early and extensive involvement of the health department
65
Q

TB misconceptions

A
  • TB doesn’t occur in young, healthy Americans
  • Believing patients are adherent with meds
  • sputum for gram stain and culture helps diagnose/exclude TB
  • Health Dept doesn’t need to be involved
  • TB best txed by pulmonologist
66
Q

what is TB often confused with in the ER

A

Pneumonia - right upper lobe infiltrate…

- always include TB in ddx of upper-lobe pulmonary infiltrate of unknown etiology

67
Q

What is important in early TB evaluation

A
  • collect sputum early!
  • consider TB-PCR test on sputum
  • call the health department (they will go to the patient!)

Pulmonology 2 (17 decks)

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