Use of interferon-gamma release assay for latent tuberculosis infection screening in older adults exposed to tuberculosis in a nursing home.

Objectives: To assess the additive value of a newly marketed interferon-gamma release assay, QuantiFERON-TB Gold In-Tube (QFT-GIT), to a single tuberculin skin test (TST) for the detection of latent tuberculosis infection (LTBI) in older adults who have been exposed to TB in a nursing home.

Design: Contact tracing included clinical examination, chest radiography, TST, and QFT-GIT in TST-negative people (TST< 5 mm).

Setting: A private nursing home.