Study participant characteristics
In total, 263 children were eligible for the study; 19 were excluded due to insufficient blood samples, 2 due to improper sample handling, 2 due to insufficient data, 10 due to technical reasons, and 5 children were excluded because the index case was diagnosed with NTMs and notMtb. infection. A total of 225 children were included in the final analysis: 33 with ATB, 48 with LTBI, 83 TB contacts, 20 with a non-TB disease, and 41 controls. Patient’s characteristics is shown in Table 1. ATB patients were older than other children (p < 0.05), and TB contacts were younger than Mtb.- infected children and non-TB group (p < 0.01). No other significant demographic differences were noted across TB classification groups. More than 96% of participants were BCG-vaccinated. Of 33 ATB patients, 9 (27.3%) had a positive culture result, 13 (39.4%) were admitted with a clinical suspicion of TB and 20 (60.6%) due to the recent TB contact. All ATB patients achieved the resolution of symptoms on antituberculous treatment. The non-TB children were diagnosed with pneumonia (n5), respiratory tract infections (n6), other respiratory diseases (n4), and “miscellanea” (n5).