Comparison of tuberculin skin test and QuantiFERON®-TB Gold In-Tube for the diagnosis of childhood tuberculosis.

BACKGROUND: Tuberculosis (TB) is an important worldwide ongoing health issue. To be able to control TB, one should not only cure active TB but also identify childhood TB patients who have the possibility to develop active disease in the future. The aim of this study was to compare a century-old tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube (QFT-GIT) test, developed as an alternative to TST and which has been claimed to be superior to TST in several ways, in the diagnosis of childhood TB. METHODS: Fifty-three children with TB between 5 months and 17.5 years of age and 92 healthy children from the same age group with no risk factors for TB were recruited into the study. All children underwent TST and QFT-GIT test and their demographic, clinic and laboratory data were recorded. Data were analyzed using SPSS 14. RESULTS: A total of 53 patients were diagnosed with TB. Mean patient age was 8.5 ± 4.3 years (range, 5 months-17.5 years). A total of 41.7% of the patients were female. Sixteen of 53 patients had confirmation on culture. QFT-GIT test was positive in 16 and TST was positive in 15 among 16 children with culture-confirmed TB. The sensitivity of TST and QFT-GIT were 93.8% and 100.0%, and the specificity of TST and QFT-GIT were 100.0% and 97.8%, respectively. With regard to the 53 TB children including those without bacteriological confirmation, QFT-GIT was positive in 33 children, and TST was positive in 44 children. The sensitivity of TST and QFT-GIT was then 83.0% and 62.3%, and the specificity, 100.0% and 97.8%, respectively. CONCLUSION: Although positive QFT-GIT test is very significant for TB, negative results will not exclude TB infection. TST and QFT-GIT used together may provide more efficient results.