I'm worried that I might have caught TB from a friend who's being treated for it, but I don't have any symptoms yet. I'm trying to figure out which test would be most accurate to detect latent TB. Can the Mantoux test and sputum AFB both find it, or is one better than the other?

Dr Shubham Chauhan

General Practitioner

• MBBS
• 4+ Yrs

Consult Now

The most accurate test for detecting latent TB is the Interferon-Gamma Release Assay (IGRA), such as QuantiFERON or T-SPOT.TB, which measures the immune response to TB proteins; the Mantoux test (Tuberculin Skin Test) is also used, but it has some limitations, such as cross-reactivity with BCG vaccine and false negatives in immunocompromised individuals; sputum AFB (Acid-Fast Bacillus) smear is used to diagnose active TB, not latent TB, so it's not relevant in your case;

Answered 29 days ago