Mycobacteria

Question 1

Distinction between people with TB infection and disease

Answer 1

-only 7- 10% infected people develop disease in their lifetimes (the remainder have latent infections)

Question 2

What percent of AIDS patients who are infected with TB will develop active disease?

Answer 2

10%

Question 3

People who are most likely to be infected with TB?

Answer 3

• Close contacts of active disease
• Foreign-born persons from areas where TB is common
• Residents of long term care facilities
• Persons who inject drugs

Question 4

People most likely to progress to TB disease

Answer 4

• HIV infection

- Recently infected within last 2 years

Question 5

TB Transmission

Answer 5

Almost exclusively airborne

Question 6

TB Pathogenesis

Answer 6

• Droplet nucleus (alveolar macrophage access)

- Regional lymph node and blood borne spread

Question 7

TB Immunopathogenesis

Answer 7

TB antigens leads lymphoproliferation and cytokine production causing granuloma formation and tissue destruction

Question 8

TB Diagnosis H & P

Answer 8

non-specific

Question 9

TB Diagnosis Radiographic examination

Answer 9

-Upper lung field infiltrates and cavities

Question 10

TB Diagnosis Labs

Answer 10

• Tuberculin (PPD) Skin test
• Sputum “AFB” smears Acid Fast
• NAAT (PCR)

Question 11

What are Nontuberculous Mycobacteria (NTM)?

Answer 11

environmental pathogens that affect predisposed hosts

Question 12

Where are NTM found?

Answer 12

• Bioaerosols
• Water
• Soil

Question 13

What is a predisposing factor for NTM?

Answer 13

a structural lung abnormality

Question 14

Differences between TB and NTM?

Answer 14

• NTM is environmental in origin, TB is human-to-human transmission
• NTM requires an underlying predisposition and does not have a long latent phases