Tuberculin skin testing in schoolchildren with and without BCG vaccination

Tuberculosis still continues to be a major health problem throughout the world, especially in developing countries. During 1990, 3648 Turkish schoolchildren with and without Bacillus-Calmette-Guerin (BCG) vaccination, aged 6-7 years and 10-12 years, were intradermals tested with 5 TU of Purified Protein Derivative (PPD) to investigate the rate of production of sensitivity to tuberculin in Elazığ. BCG vaccination was not documented in 820 (22.4%) children. Tuberculin positivity, representing infection with Mycobacterium tuberculosis, rates of the unvaccinated children were found as 46 per 1000 cases for the 6-7 age group and 107 per 1000 for the 10-12 age group. The overall case rate for the latter children was more than two times than that of the former children. In the two age groups, tuberculin negativity rates in the unvaccinated to vaccinated and revaccinated children were gradually decreased from 95.4%, 89.3% to 49.8%, 42.1% and 20.5%, 20.7%, respectively. Similarly, tuberculous infection rate was gradually declined as 57.3, 28.9 and 9.7 per 1000 in the unvaccinated, vaccinated and revaccinated children, respectively. Active disease was diagnosed in eight children. Of the eight children, six were unvaccinated and two were vaccinated.