Infection by systems (pulmonary)

Question 1

Expected pathogens of community-acquired pneumonia (CAP)

Answer 1

Typical: streptococcus pneumoniae, Haemophilus influenzae

Atypical : mycoplasma pneumoniae, chlamydia pneumoniae, legionella pneumophila

Question 2

Expected pathogens of hospital-acquired pneumonia (HAP)

Answer 2

• Streptococcus pneumoniae
• Haemophilus influenzae
• Pseudomonas aeruginosa
• Coliforms eg. E.coli
• Other gram -ve bacteria eg Acinetobacter
• MRSA

Question 3

Hospital-acquired pneumonia (HAP) is pneumonia which occurs ____after hospital admission

Answer 3

≥ 48hrs

Question 4

Ventilator-associated pneumonia (VAP) is pneumonia which occurs _____ after endotracheal admission

Answer 4

48-72 hrs

Question 5

Aspiration pneumonia is from aspiration of food/mouth flora/ gastric content in patients with _____, _____ or _____

Answer 5

aspiration of food/mouth flora/ gastric content in patients with poor gag reflex, difficulty swallowing or loss of consciousness

Question 6

Expected pathogens of aspiration pneumonia

Answer 6

• Patient’s mouth flora (streptococci, anaerobes)

- HAP pathogens if patient has been in hospital

Question 7

Infections in immunocompromised : rare pathogens are

Answer 7

Candida species, Aspergillus species (bone marrow), Pneumocystis jirovecii (HIV)

Question 8

To test for CAP and HAP bacteria, order:

Answer 8

Gram stain, culture & sensitivity (C&S)

Question 9

To test for virus/atypical bacteria, order:

Answer 9

PCR

Question 10

If patient is septic or pyrexial, order:

Answer 10

blood culture

Question 11

Extra test for immunocompromised patients:

Answer 11

fungal culture

Question 12

Best technique for identifying TB

Answer 12

Acid-fast aerobic bacilli

Question 13

How does mycobacterium TB spread

Answer 13

Spread via inhalation of droplet nuclei, aerolised by coughing, sneezing, talking

Question 14

Sputum AFB smear positive means:

Answer 14

highly infectious

Question 15

Latent TB:

symptomatic?
infectious?

Answer 15

Asymptomatic and non-infectious

Question 16

Is latent TB able to reactivate?

Answer 16

yes

Question 17

1) Tests to send for latent TB

2) The tests depend on ______ and CANNOT differentiate ______

Answer 17

• Tuberculin skin test (TST)
• Interferon Gamma Release Assay (IGRA)

The tests depend on cell-mediated immunity and CANNOT differentiate btw active and latent TB

Question 18

Most common (stage)TB

Answer 18

Post-pri TB

Question 19

Tests to send for active TB

Answer 19

Step1 : Early morning sputum: 2 specimens

Step 2: AFB staining and culture

Question 20

How long does TB culture take?

Answer 20

3-8 weeks!

Question 21

Treatment of TB

Answer 21

Empirical treatment with 4 drugs: Rifampicin, Isoniazid, Ethembutol, Pyrazinamide

Question 22

Usual duration of TB treatment

Answer 22

6 months

Question 23

TB drugs CANNOT interact with

Answer 23

HIV drugs eg. lamivudine

Question 24

Why is MDR TB or XDR TB a problem?

Answer 24

Both are more difficult to manage; treatment options are not as effective and associated with side effects.
Prolonged treatment duration is required.
XDR-TB is associated with poorer outcomes

Question 25

Normal process for testing (duration)

1. Gram stain
2. Culture
3. Sensitivity

How does the normal process defer from TB process?

Answer 25

1. Send for gram stain (gram stain results come back on the day itself)
2. Culture (1-3 days) (but some bacteria if need to take longer: 3-5 days)
3. Sensitivity: the day after culture results

TB–
Culture: 3-8 weeks
Sensitivity: several weeks after culture