As no recent report has been made concerning the tuberculin survey of healthy young adults in Japan, we checked all the Tohoku University undergraduate and postgraduate students by tuberculin test for the assessment of TB-situation in 1998. The sample included 5, 517 students and postgraduates (3, 888 males and 1, 629 females 31% of all subjects to be tested) who were evaluated on the basis of the redness of the skin test. The average age of the subjects was 22.3±3.1 years old (ranging from 18 to 51). As a result of this survey, 5, 032 (91.2%) were positive and 485 (8.8%) were negative, and the average diameter of redness was 28.5±19.2 mm. Non-reactors received an additional BCG vaccination. Subjects showing strongly-positive (20.1%) results were rechecked by physical examination and chest X-ray, and none was found to require treatment by anti-TB drugs. Our findings also demonstrated that the diameter of redness was larger in the group previously BCG-vaccinated than in the group who had not received BCG vaccination previously (p<0.01).
