Given the fact that “diagnostic performance of an enzyme-linked immunospot assay for interferon-gamma (IFN) in extrapulmonary tuberculosis varies between different sites of disease”,1 the authors of the study in which some children had pulmonary tuberculosis (PTB) and others had extrapulmonary tuberculosis (EPTB)2 should, arguably, have specified the diagnostic performance of each of the interferon γ release assays (IGRA) versus tuberculin skin test (TST) according to the site of tuberculous infection. The latter was the practice followed in a study comprising a paediatric cohort, which included …