Clinical and laboratory procedures
Demographics, history and clinical findings were recorded systematically
using a case report form. All participants underwent peripheral blood
testing including QFT. Children suspected of ATB and contact tracing
referrals underwent standard diagnostic procedures encompassing TST,
QFT, chest X-ray, and, if required, histological and bacteriological
evaluation (microscopy, PCR, and culture). Not all participants received
TST due to recurrent shortages of Purified Protein Derivative (PPD). For
ethical reasons, we did not perform TST, chest X-ray and microbiological
studies in the control group. All children with ATB received standard
combined antituberculous treatment, children with LTBI and TB contacts
aged < 5 years were offered preventive chemotherapy. A
subgroup of patients underwent follow-up examination two months after
treatment onset.