TB QuantiFERON-TB Gold Plus Blood Test

This private interferon-gamma release assay (IGRA) blood test checks for latent or active Mycobacterium tuberculosis infection in a single visit. The catalogue test price is £155.00 plus a £50 phlebotomy fee, with results in 3 days.

Unlike the traditional Mantoux tuberculin skin test, QuantiFERON-TB Gold Plus requires only one clinic visit and is not affected by prior BCG vaccination.

Written by Mr Stephen Lingam. Reviewed by Dr Mohammad Bakhtiar (GMC 4694470) on 18/10/2026.

Will a previous BCG vaccine cause a false-positive QuantiFERON result?

No. QuantiFERON-TB Gold Plus uses tuberculosis-specific antigens not found in the BCG vaccine, so prior BCG vaccination does not cause a positive result.

Is this test accepted for occupational health and pre-biologic screening?

Yes. QuantiFERON-TB Gold Plus is the standard UKAS-accredited IGRA blood test used for healthcare worker clearance, visa medicals and screening before immunosuppressive therapy.

Do I need to fast before a TB blood test?

No fasting is required before your blood draw at 117a Harley Street.

What happens if my QuantiFERON result is positive?

A positive result indicates immune sensitization to Mycobacterium tuberculosis and requires medical evaluation and a chest X-ray to distinguish latent infection from active disease.