Bacteriology - Tuberculosis

Question 1

Decide whether each of the f ollowing statements is more closely associated with 1° or 2° TB:

Radiographic finding = Ghon complex; classically affects lower lobes

Answer 1

1°TB

Question 2

Decide whether each of the f ollowing statements is more closely associated with 1° or 2° TB:

Miliary TB

Answer 2

2°TB

Question 3

Decide whether each of the f ollowing statements is more closely associated with 1° or 2° TB:

Fibrocaseous cavitary lung lesion; classically affects apical lungs (↑ affinity for ↑ O2 environment)

Answer 3

2°TB

Question 4

Decide whether each of the f ollowing statements is more closely associated with 1° or 2° TB:

Symptoms of cough/hemoptysis, fever, night sweats, and weight loss

Answer 4

2°TB

Question 5

What type of hypersensitivity reaction is seen after infection with M. tuberculosis?

Answer 5

Type IV or delayed-type hypersensitivity (basis for PPD test)

Question 6

What unique type of cell is seen in association with caseating granulomas in TB?

Answer 6

Langerhans giant cell

Question 7

What is the mode of transmission of M. tuberculosis!

Answer 7

Respiratory droplets

Question 8

What term describes the lymphatic and hematogenous spread of TB, causing numerous small foci of infection in extrapulmonary sites?

Answer 8

Miliary TB

Question 9

Name five common sites of extrapulmonary TB:

Answer 9

1. CNS (tuberculous meningitis)
2. Vertebral bodies (Pott disease)
3. Psoas major muscle → abscess
4. GI tract (liver and cecum)
5. Cervical lymph nodes →scrofuloderma

Question 10

What is an effective screening tool for latent TB?

Answer 10

PPD test

Question 11

How is active TB infection diagnosed?

Answer 11

Clinical and radiologic signs of 2° TB and acid-fast bacilli in sputum

Question 12

What is the management of PPD + latent TB?

Answer 12

Treatment with INH + pyridoxine (vitamin B6) for 9 months

Question 13

What is the treatment for active TB?

Answer 13

Respiratory isolation and initial four-drug therapy (RIPE: Rifampin, INH, Pyrizinamide, Ethambutol)

Question 14

What is the major toxicity of most TB drugs?

Answer 14

Hepatotoxicity; INH → vitamin B 6deficiency; ethambutol → optic neuritis

Question 15

Decide whether each of the f ollowing statements is more closely associated with 1° or 2° TB:

Radiographic finding = Ghon complex; classically affects lower lobes

Answer 15

1°TB