Diagnosing syndromes of infection

Question 1

What are two tests to confirm a DX of LTBI?

Answer 1

TST (>=8w)

IGRA

Question 2

A patient comes in. TB is on your DDX (along with other possible causes)

What differentiating tests should you order (for microbiology)?

Answer 2

For TB:

• CXR
• AFB smear + cx (on esputum, if possible).

For DDx:

• Fungal cx
• Legionella cx
• RPP
• Blood cx (if F)