[Group tuberculous contamination in preschoolers].

The study of a new collective tuberculosis contamination is proper for us to report news about the antituberculosis fight. In 1997, an ill teacher with cavity produced 19 cases of tuberculin turnings in a class with 25 children, but none of them had tuberculosis. We tried to find an explanation. We studied another 3 epidemiological events. In 1970, a teacher from Holbav produced 80 tuberculin turnings with 42 ill children. In Săcele another teacher with cavity produced 39 tuberculin turnings with 5 ill children. In Prejmer, in 1988 a sick child with cavity made himself 28 tuberculin turnings with a single case of illness. We tried to explain these differences: similar sources (patients with cavities) and the same conditions of illness but different effects. Our epidemiological investigations showed that in Holbav only 3.6% of children had BCG vaccine; in Săcele were 18%; in Prejmer were 98%; in Codlea 96%. BCG vaccination prevents tuberculosis. But in this case is another problem, did all the tuberculin turnings signify a virulent infection? After a year when we tested again the children, we found that for 58% of tuberculin turnings the reaction diminished considerably. We consider that, this is the particularity of the evolution of the postvaccinal allergy. We conclude that hyperreactivity may be a transitory exacerbation of the postvaccinal allergy and not an evidence of the infection. BCG vaccination reduces the risk of tuberculosis even when the infection is important and virulent.