[Study of contacts in children and adolescents using the QuantiFERON®-TB Gold In-Tube]

To compare the results of the Mantoux Tuberculin Test (TT) and the QuantiFERON TB® Gold In-Tube (QFT-GIT) in a population of children and adolescents with TB contacts.

A prospective study using data collected on children and adolescents (< 17years) from a Health District of 300,000 inhabitants in the Basque Country (Spain) recruited into a TB contact study over a period of almost three years. The study included performing the Tuberculin Test using the Mantoux technique (with 2-TU of RT-23 PPD RT23 and Tween 80), and the QFT-GIT simultaneously, and collecting the demographic and clinical data.

Of the 160 children included in the study, 14% had a positive TT (≥ 5mm) and 11% a positive QFT-GIT. There was 95%-96% agreement between the tests, depending on the TT cut-off point chosen, and was higher in non-vaccinated children (100%) and in children less than 5 years-old (100%). A significant relationship was observed between a positive result for both tests with exposure in the home. The use of QFT-GIT in the screening of latent TB infection could reduce preventive treatments by 28%-34% compared with conventional screening with the TT.

The behaviour of QFT-GIT was comparable to the TT in identifying children with a tuberculosis infection; therefore it could potentially replace the TT.