Tuberculosis

Question 1

Tuberculosis (TB)

Answer 1

• infectious disease caused by Mycobacterium tuberculosis
• gram-positive
• acid-fast bacillus (AFB)
• spread via airborne droplet

Question 2

Multi-Drug Resistant TB

Answer 2

• M. tuberculosis develops resistance to isoniazid (INH) and rifampin
• can occur when the drugs used to treat TB are misused or mismanaged

Question 3

Primary TB

Answer 3

• infection occurring in previously uninfected host
• NO SYMPTOMS
• occurs when the bacteria are inhaled but there is an effective immune response, causing the bacteria to become inactive
• primary TB = active disease develops within the first two years of infection
• signs of infection soon after being exposed to TB

Question 4

Latent TB infection (LTBI).

Answer 4

• TB infection in a person who does not have the active TB disease
• An estimated 10 to 15 million Americans have LTBI. Up to 10% of them will develop active TB disease at some point in their lives

Question 5

Active TB

Answer 5

• results if the initial immune response is inadequate, the body cannot contain the organisms, and the bacteria replicate.

Question 6

Postprimary TB, or reactivation TB

Answer 6

TB disease occurring two or more years after the initial infection

Question 7

Tuberculin skin test (TST)

Answer 7

• induration (hardness, not redness) at the injection site means the person has been exposed to TB and has developed antibodies
• intradermal administration of tuberculin
• Sensitivity remans for life and individual should not be tested again
• Response decreases in immune compromised
• Reactions > or equal to 5mm considered positive

Question 8

Interferon-γ release assays (INF-gamma)

Answer 8

• used to detect the IFN-γ released from T cells in response to mycobacterial antigens

Question 9

Chest x-ray

Answer 9

• diagnosis cannot be based solely on x-ray because other diseases may mimic TB

Question 10

Bacteriologic studies

Answer 10

stained sputum smears for acid-fast bacilli (AFB) can identify tubercle bacilli; cultures to grow tubercle bacilli confirm diagnosis

Question 11

Directly observed therapy (DOT)

Answer 11

• Providing anti-tuberculosis drugs directly to patients and watching as they swallow
• preventing the development of drug resistance.