Amer Acad Pediatrics. Amer Acad Pediatrics Red Book 2018 Tuberculosis.pdf. 2018. https://redbook.solutions.aap.org/chapter.aspx?sectionid=189640207&bookid=2205.
“For children younger than 2 years, TST is the preferred method for detection of M tuberculosis infection. For children 2 years and older, either TST or IGRA can be used, but in people previously vaccinated with BCG, IGRA is preferred to avoid a false-positive TST result caused by a previous vaccination with BCG. If a BCG-vaccinated child who is 2 years and older has a positive TST, IGRA can be performed to help determine whether it is attributable to LTBI or to the previous BCG vaccine.”