Figure 1b   shows the six reasons nurses performed an Interferon-gamma release assay providing in detail bacille Calmette-Guerin status. The most common reason was number two showing 228 Interferon-gamma release assay recipients with known bacille Calmette-Guerin vaccination and tuberculin skin test measurement of 10-15 mm. Reason four shows 120 contact individuals where bacille Calmette-Guerin vaccination status was unknown and Interferon-gamma release assay only replaced the tuberculin skin test.