Tuberculin Skin Tests Among Medical Students With Prior Bacille-Calmette Guérin Vaccination in a Setting With a High Prevalence of Tuberculosis

Abstract
Presence of a bacille Calmette-Guérin vaccination scar in medical students was an independent factor associated with initial tuberculin skin test reactions of 10–19 mm (P = .03) and booster effects of 6–9 mm (P = .02). These findings suggest that an initial tuberculin skin test reaction of at least 20 mm or a booster effect of at least 10 mm will reveal tuberculosis among students with prior bacille Calmette-Guérin vaccination.