Comparison of Tuberculin Skin Test and QuantiFERON-TB Gold Test in Children

Abstract

Objective: Interferon-γ release tests (IGRAs) and tuberculin skin testing (TST) are important helpful tests for diagnosing tuberculosis (TB) disease in children. It was aimed to compare the sensitivity and compatibility of QuantiFERON-TB Gold In-tube test (QFT) and TST used in children with TB and Latent tuberculosis infection (LTBI). Material and Methods: A total of 118 patients between September 2018 and January 2020 were included in the study prospectively to determine the case characteristics related to the performance of the tests, and to measure the sensitivity of these tests. Results : A total of 118 patients were included in the study; and 13 (11%) patients presented with pneumonia symptoms and 7 (6%) patients were diagnosed with TB in active TB Contact Screening. TB diagnosis was made 20% microbiologically. Mycobacterium tuberculosis culture positivity was found to be 10%. None of the patients had acid-resistant bacilli positivity. The male / female rate was 74/44 in our study (p = 0.006). The median age was found to be 14 (1.17-19.2 years) in males, and 12 (0.33 -17.9 years) in females. The mean age of the LTBI Group was higher than the TB Group at significant levels (p <0.05), and was similar to the non-infected group (p>0.05). A total of 53.5% of the patients had a history of meeting someone with tuberculosis, and 97 children were vaccinated with BCG (82.2%). TST and QFT positivities were 19.5% and 22%, respectively. The most common radiological finding that was detected was consolidation areas. While there was moderate compliance between TST and IGRA test in patients with TB diagnosis (kappa =0.50, p=0.025), no compliance was found between tests in LTBI patients. In patients who were diagnosed with TB and LTBI, the sensitivity of TST was found to be 51.1%, and the sensitivity of QFT was found to be 60.4%. Conclusion: TST seems to continue as the most preferred method of diagnosis in rural areas with limited resources and poor laboratory infrastructure due to the costs and technical considerations.