Quantiferon Gold

Is it necessary to take precautionary Isonizid?

Where were you born?
Mexicans and Europeans will always be positive, but have not been exposed

Both the PPD skin test and the test Quantiferon will identify people with latent TB infection. They basically test the same phenomenon, specific cell-mediated immunity to MTB. Quantiferon claims to be as sensitive as skin testing, but I heard stories that it is not.

It is possible that you have had exposure to TB, but it is also possible that you react to PPD due to exposure to other mycobacteria (eg, MAI).

Anyway, I think the result would be considered impaired and a new test after a short period or follow-up with the chest radiograph is appropriate.

I do not think that isoniazid is in itself an appropriate treatment for latent Tb, but I'm not sure.

I think you need to consult an infectious disease Doc.

If you are not aware of a recent exhibition, I do not think there is a problem with a new test in a month or two.

TST may be unreliable, especially when it is positive.

If you have received BCG (vaccine) or have had TB before, it may cause a false positive TST (which means you do not have tuberculosis, even if TST positive).

If you eventually showed QFT negative, then you do not have TB (latent or active) and the treatment is not necessary.

PPD positive means that you have been exposed, negative QuantiFERON means you do not have active disease ... does not mean that you are not infected, that is why isoniazid is indeed the most appropriate treatment to prevent the expression of the disease.