Role of the QuantiFERON(R)-TB Gold In-Tube assay in screening new immigrants for tuberculosis infection.

This study aimed to estimate the risk of progression to active tuberculosis (TB) within 2 yrs after entry in newly arriving immigrants who were screened with the QuantiFERON®-TB Gold In-Tube assay (QFT-GIT; Cellestis, Carnegie, Australia). In a case-base design, we determined the prevalence QFT-GIT-positive subjects among a representative sample of immigrants aged ≥ 18 yrs who arrived between April 2009 and March 2011 (the base cohort). Active TB patients (cases) within 2 yrs post-arrival in 2005, 2006 or 2007 were extracted from the Netherlands Tuberculosis Register.

Follow-up study of tuberculosis-exposed supermarket customers with negative tuberculin skin test results in association with positive gamma interferon release assay results.

We report a follow-up study of 29 subjects with negative tuberculin skin test (TST) results in association with positive gamma interferon release assay (IGRA) results, mainly due to responses to CFP-10 in the T-SPOT.TB assay, during a contact investigation. One year later, 12/29 subjects (41%) had converted to positive TST results in association with negative IGRA results.

Comparison of two interferon-gamma assays and tuberculin skin test for tracing tuberculosis contacts.

Background: The tuberculin skin test (TST) has low specificity. QuantiFERON-TB Gold (QFT-G) and T-SPOT.TB are based on interferon (IFN)-gamma responses to Mycobacterium tuberculosis-specific antigens.