Table 2.
Distribution of QFT-Plus and TB-Feron IGRA results and agreement between the groups.
| IGRA Patterns | Overall (%) (n = 335) |
ATB (%) (n = 40) |
P-LTBI (%) (n = 75) |
H-LTBI (%) (n = 70) |
HC (%) (n = 150) |
|
|---|---|---|---|---|---|---|
| Overall positivity of QFT-Plus | 168 (50.1) | 36 (90.0) | 63 (84.0) | 69 (98.6) | 0 (0.0) | |
| Overrall Positivity of TB-Feron | 178 (53.1) | 35 (87.5) | 68 (90.7) | 68 (97.1) | 7 (4.7) | |
| Q-Positive | T-Positive | 164 | 34 | 63 | 67 | 0 |
| TB1+ and TB2+ | 158 (96.4) | 31 (91.2) | 63 (100) | 64 (95.5) | 0 (0.0) | |
| TB1 alone | 2 (1.2) | 0 (0.0) | 0 (0.0) | 2 (3.0) | 0 (0.0) | |
| TB2 alone | 4 (2.4) | 3 (8.8) | 0 (0.0) | 1 (1.5) | 0 (0.0) | |
| Q-Positive | T-Negative | 4 | 2 | 0 | 2 | 0 |
| TB1+ and TB2+ | 3 (66.7) | 2 (100) | 0 (0.0) | 1 (50.0) | 0 (0.0) | |
| TB1 alone | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | |
| TB2 alone | 1 (33.3) | 0 (0.0) | 0 (0.0) | 21(50.0) | 0 (0.0) | |
| Q-Negative | T-Positive | 14 | 1 | 5 | 1 | 7 |
| Q-Negative | T-Negative | 151 | 3 | 5 | 0 | 143 |
| Q-Negative | T-Indeterminate | 2 | 0 | 2 | 0 | 0 |
| Agreement of each group (%) | 94.0 | 92.5 | 90.7 | 95.7 | 95.3 | |
Abbreviation: IGRA, interferon-gamma-releasing assay; QFT-Plus and Q, QuantiFERON-TB Gold Plus; T, TB-Feron; TB1 or 2, TB antigen tube 1 or 2; ATB, active tuberculosis; P-LTBI, patients with immunocompromised status and latent TB infection; H-LTBI, health care workers with latent TB infection; HC, health care workers confirmed with previous negative IGRA and low risks.