G'day terryd,There are only three commercially available...

G'day terryd,

There are only three commercially available diagnostics for latent TB - skin test, Quantiferon and T-spot. I am not aware of any other diagnostics that are anywhere near close to having been proven, let alone reaching commercial viability.

I believe that your contact may have confused diagnostics for latent TB with diagnostics for active TB.

To establish the drug resistance of a TB infection, I believe you would need to be dealing with the TB bacterium itself, rather than the immune response (you need to do it this way because when TB is latent you cannot actually isolate the bacterium itself). This makes me feel that the diagnostic that your friend is talking about is a diagnostic for Active TB only. QFT is a diagnostic for both Active and Latent TB. There is a place for diagnostics for Active TB only but that is not currently QFTs role.