Performance of interferon-γ release assays and tuberculin skin test (TST) in all children according to age
| Subjects | <5 yrs | ≥5 yrs | |||||||||||||||
| Subjects | TST >15 mm | QFG-IT | T-SPOT.TB | Subjects | TST >15 mm | QFG-IT | T-SPOT.TB | ||||||||||
| Pos. | Neg. | Ind. | Pos. | Neg. | TF | Pos. | Neg. | Ind. | Pos. | Neg. | TF | ||||||
| All | 209 | 82 | 19 (24) | 13 (16) | 62 (76) | 7 (8) | 11 (14) | 59 (74) | 10 (12) | 127 | 72 (57) | 67 (53) | 53 (42) | 7 (5) | 59 (47) | 59 (47) | 8 (6) |
| Active | 91 | 26 | 6 (23) | 6 (23) | 19 (73) | 1 (4) | 3 (12) | 19 (73) | 4 (15) | 65 | 33 (51) | 36 (55) | 22 (34) | 7 (11) | 31 (48) | 29 (45) | 4 (6) |
| Definite | 25 | 2 | 1 (50) | 1 (50) | 1 (50) | 0 | 0 | 1 (50) | 1 (50) | 23 | 19 (82) | 19 (82) | 2 (9) | 2 (9) | 14 (64) | 8 (36) | 0 |
| Probable | 38 | 11 | 4 (36) | 4 (36) | 7 (64) | 0 | 2 (18) | 7 (64) | 2 (18) | 27 | 14 (52) | 16 (59) | 9 (33) | 2 (7) | 15 (56) | 10 (37) | 2 (7) |
| Possible | 28 | 13 | 3 (23) | 1 (8) | 11 (84) | 1 (8) | 1 (8) | 11 (84) | 1 (8) | 15 | 0 | 1 (7) | 11 (73) | 3 (20) | 2 (13) | 11 (73) | 2 (13) |
| LTBI | 118 | 56 | 13 (23) | 7 (13) | 43 (76) | 6 (11) | 8 (15) | 40 (74) | 6 (11) | 62 | 39 (63) | 31 (50) | 31 (50) | 0 | 28 (45) | 30 (48) | 4 (7) |
Data are presented as n or n (%). QFG-IT: QuantiFERON-TB Gold In-tube system (Cellestis, Carnegie, Australia); pos.: positive; neg.: negative; ind.: indeterminate result; TF: test failure; LTBI: latent tuberculosis infection. T-SPOT.TB is manufactured by Oxford Immunotec, Abingdon, UK.