Abstract: Objective  To compare the tuberculosis (TB) screening results among university students by using purified protein derivative of BCG (BCG-PPD) and purified protein derivative of tuberculin (TB-PPD) skin-test.  Methods  The TB screening (PPD skin-test) results obtained from 2821 students in 3 universities, which located in Xicheng district of Beijing, from 2012 to 2013 were retrospectively analyzed. The students were divided into two groups according to the different PPD reagents used: BCG-PPD group consisting of 1386 students who received BCG-PPD skin-test and TB-PPD group consisting of 1435 students who received TB-PPD skin-test. The test result was read at 72 hours and the maximum transverse diameter of the induration was measured. Chest X-ray was performed to the students with strong-positive. SPSS 11.5 software was applied for statistical analysis. Rank sum test was used for comparison of diameter of induration in two groups. Chi-square test was used for comparison of TB screening results and frequency distribution of PPD results in two groups. When the theoretical value was less than 1, Fisher’s exact test was used. The correlation between BCG scar and PPD positive result was analyzed using logistic regression, P<0.05 was considered as statistically significant.  Results The median diameter of induration in BCG-PPD group (6 mm) was larger than that in TB-PPD group (0 mm); and the difference was statistically significant (Z=－10.034, P<0.05) between the two groups. The positive rate of BCG-PPD group (54.8%, 759/1386) was significantly higher than that of the TB-PPD group (32.7%, 469/1435) (χ²=139.818, P<0.05); the strong-positive rate of BCG-PPD group (6.6%, 92/1386) was significantly higher than that of the TB-PPD group (3.4%, 49/1435) (χ²=15.425, P<0.05); the adverse reaction rate of the BCG-PPD group (1.9%, 27/1386) was significantly higher than that of the TB-PPD group (0.4%, 6/1435) (χ²=14.274, P<0.05). BCG scar was associated with the PPD positive result; the students with BCG scar were more likely to have PPD positive results (OR=2.046, 95％CI=1.630-2.569, P<0.05).  Conclusion In TB screening among the university students, the strong positive rates and the abnormal reaction rates of TB-PPD and BCG-PPD skin test were dif-ferences. Further research is needed to be conducted.

Key words: Tuberculosis, pulmonary/prevention &, control, BCG vaccine, Tuberculin test, Skin tests, Students, Mass screening