These guidelines, whilst welcomed, listed areas of performance that remained uncertain viz
• in young children, especially those aged < 5 years;
• in persons with impaired immune systems;
• in persons who undergo periodic screening;
• incidence of TB disease after diagnosis;
• length of time between exposure, infection and a positive QFT-G test result;
• economic evaluation and decision analysis comparing QFT-G with TST;
• changes in QFT-G results during therapy for both LTBI and TB disease;
• ability to detect reinfection after treatment for both LTBI and TB disease; and
• performance in targeted testing programs and contact investigations.
Since the Guidelines were published numerous studies dealing specifically with QuantiFERON were published in peer reviewed journals
CDC convened an expert panel that included 26 basic scientists, clinical researchers, clinicians, and public health officials from both inside and outside the United States.
To guide the evaluation, CDC provided the expert panel with a number of publications in the literature..
..The expert panel and other researchers in the field reviewed studies regarding the performance of both FDA-approved IGRAs..
..the expert panel agreed IGRA is a more specific test than TST
Whilst we await the updated guidelines we have been given a sneak peak, importantly these guidelines will be harmonised and coordinated with the American Thoracic Society, Infectious Diseases Society of America and American Academy of Pediatrics
Clearly the weight of peer reviewed studies has swung all expert opinion around to support IGRAs and QuantiFERON as the "preferred test"
