Summary:
Objective: To compare the performance of QuantiFERON-TB Gold-In Tube (QFT-GIT)
assay with the tuberculin skin test (TST) for the diagnosis of TB in children.
Methods: Cross- sectional study of all children (n=286) referred to our
Tuberculosis Clinic, including patients with active TB disease (n=37), TB
contacts (n=99) and other high risk children (n=150), Participants were tested
with both TST and QFT-GIT. Comparison of tests within groups was conducted with
the k statistic. Multivariate logistic regression was used to model TST and
QFT-GIT outcome separately.
Results: QFT-GIT was positive in 125/286 (43.7%) and TST in 220/286 (76,9%)
participants. Among BCG (-) children agreement between tests was excellent
(k=1) in those with active TB disease as well as in TB contacts (k=0.91).
Agreement was fair in BCG(+) patients, particularly among high-risk children
with negative contact history. Previous BCG immunization was significantly
associated with TST outcome.
Conclusion: QFT-GIT compares with the TST in the diagnosis of active TB
disease and LTBI in TB contacts in children but it has higher specificity. This
assay use may improve the accuracy of TB diagnosis, particularly among BCG-
vaccinated children.
Keywords:
Tuberculosis, Children, Diagnosis, Tuberculin skin test, Quantiferon
