Objective Recent studies found that a chest x-ray (CXR) has limited value in the assessment of asymptomatic adults with tuberculosis (TB) infection. We aimed to determine in asymptomatic children with a positive tuberculin skin test and/or interferon-γ release assay (TST/IGRA) whether a CXR identifies findings suggestive of pulmonary TB.

Design, setting and patients All children with TB infection (defined as TST ≥10 mm and/or positive IGRA) presenting to The Royal Children's Hospital Melbourne during a 54-month period were included. All CXRs were reviewed by a senior radiologist blinded to the clinical details. The medical records of those with radiological abnormalities suggestive of TB were examined to identify those who were asymptomatic when the CXR was done. Demographical data were also collected.

Results CXRs were available for 268 of 330 TB-infected children, of whom 60 had CXR findings suggestive of TB. Of the 57 for whom clinical details were available, 26 were asymptomatic. Of these asymptomatic children with radiological abnormalities suggestive of TB, 6 had CXR findings suggestive of active TB, 14 had CXR findings suggestive of prior TB and 6 had isolated non-calcified hilar lymphadenopathy. The six with findings suggestive of active TB represented 2.6% (95% CI 0.9 to 5.5%) of asymptomatic TST/IGRA-positive children with evaluable CXRs. One child with isolated hilar lymphadenopathy had microbiologically-confirmed TB.

Conclusions In contrast to the results from studies in adults, a CXR identified a small but noteworthy number of children with findings suggestive of pulmonary TB in the absence of clinical symptoms.