COMPARISON OF SENSITIVITIES TO 2 COMMERCIALLY AVAILABLE TUBERCULIN SKIN-TEST REAGENTS IN PERSONS WITH RECENT TUBERCULOSIS

Discrepancies have been reported between results obtained with tubercu lin skin tests (TSTs) performed with use of different reagents, We com pared TST results and determined the sensitivities of the two commerci ally available TSTs in 51 human immunodeficiency virus-negative person s with culture-confirmed active tuberculosis, Simultaneous TSTs were d one with use of the Mantoux method and 5-tuberculin unit purified prot ein derivative (PPD) tuberculin preparations from single lots of Aplis ol and Tubersol, Aplisol skin test reactions ranged from 5 mm to 26 mm (median, 16.0 mm), and Tubersol reactions ranged from 7 mm to 23 mm ( median, 15.0 mm), The mean difference in paired reaction sizes for the two reagents was 0.58 mm and was not statistically different from zer o (P value, 0.26), The difference in reaction sizes was less than or e qual to 2 mm in 55% and greater than or equal to 5 mm in 18% of patien ts, With a cutoff of either 5 mm or 10 mm to define a positive reactio n, all results were concordant, with sensitivity of 100% and 96%, resp ectively, We found indistinguishable reaction size distributions and m edian TST results for the two commercially available PPD TST reagents, Aplisol and Tubersol, in a population with recent culture-proven tube rculosis.