Evaluating a 24-year tuberculosis screening in first-grade elementary schoolers in a low-burden area

Early diagnosis of tuberculosis infection can significantly contribute to the control of the disease. The aim of the present study was to describe the tuberculin skin test (TST) trends over a 24-year period (1990-2013) and explore the value of universal tuberculosis screening in a low-burden area.

All first graders that underwent TST during the 24-year study period (1990-2013) on the island of Crete, Greece, were retrospectively included in the study.

A total of 82 402 children (92.3% of Greek nationality; 51.0% male) underwent TST, of whom 335 (0.41%, 95% CI 0.37-0.46) were found to have positive TST while 0.27% of the study population had a TST between 5 and 9 mm. The tuberculin index declined significantly between 1990-1994 and 2010-2013 (0.67 vs 0.26; RR 2.73, 95% CI 1.82-4.09; p < 0.0001). Positive TST result was significantly higher in the immigrant than the native group (0.66% vs 0.24%; RR 3.76 95%, CI 2.89-4.84; p < 0.0001). In the last study years, 386 children (488 native; 153 immigrant) should be tested for one to be found TST positive.

Our findings question the massive tuberculin testing in low-burden areas and point to selective screening of high-risk groups.