Contact investigation in a primary school using a whole blood interferon-gamma assay.

Objectives: To evaluate the usefulness of QuantiFERON-TB Gold (QFT-G) for children.

Methods: Students in a primary school exposed to a tuberculosis patient were investigated using the tuberculin skin test (TST), chest X-ray examination and sequential QFT-G tests.

Results: The first QFT-G test was conducted one month after the end of exposure for 308 of the 313 children, with 6 (1.