Infection with M. tuberculosis (MT) is difficult to diagnose in young BCG (Bacillus Calmette-Guérin) vaccinated children using Mantoux test alone, as a positive test result may be due to infection with MT and previous BCG vaccination. We aimed to test the T-SPOT. TB test for BCG-vaccinated children aged five and younger in two groups — with or without contact with an active tuberculosis (ATB) patient. Prospectively a study group of 121 children (having contact with ATB patient) and a control group of 64 children (without known contact with ATB patient) were examined using Mantoux and T-SPOT. TB tests. The T-SPOT. TB test was positive in 66 (54.5%) study group children and in 2 (3.1%) control group children (P < 0.01). Induration in the Mantoux test ≥ 10 mm was observed in 62 (91.0%) of 68 T-SPOT. TB positive children, and 34 (29.1%) of 117 T-SPOT. TB negative children (P < 0.01). In the group with a negative T-SPOT. TB result boosting of the Mantoux test was observed in 21 (66%) of 32 children who had received repeated Mantoux testing before being included in the study. According to the results, the application of the T-SPOT. TB test is reasonable for primary contact children evaluation and follow-up contact children for whom primary tests did not confirm infection with MT.
