TB contact tracing for young children: an Australian cascade of care review

OBJECTIVE: To evaluate care cascades for programmatic active case finding and latent TB infection (LTBI) management in young child TB contacts (aged <5 years) in Victoria, Australia. DESIGN: This was a retrospective review of public health surveillance data to identify contacts of all pulmonary TB cases notified from 2016 to 2019. RESULTS: Contact tracing identified 574 young child contacts of 251 pulmonary TB cases. Active TB was found in 28 (4.9%) contacts, none of whom had previously received bacille Calmette-Guerin vaccination, and 529 were tested for TB infection using the tuberculin skin test (TST). The overall TST positivity was 15.3% (95% CI 0.1–0.2). Among the 574 children, 150 (26.1%) were close contacts of sputum smear-positive cases and 25 (16.7%) of these were not referred to TB clinics. Of the 125 referred, 81 were considered to have LTBI, 79 agreed to commence TB preventive treatment (TPT) and 71 (89.9%) completed TPT. Following completion of TPT, no child was subsequently diagnosed with active TB. CONCLUSION: There was a high yield from active case finding and uptake of TPT. Notable losses in the cascade of care occurred around referral to tertiary clinics, but high treatment completion rates and good outcomes were found in those prescribed treatment.