| 
      Modified ‘cut-off’ point value of TST induration was more than 10 mm, score (-)=no
score for excluded case (due to missed follow-up or result reading after 5days),
mm=millimetre induration
        | Mantoux | Score grade | LTBI diagnosis | Final result | n (%) |  
        | response (mm) |  
        |  |  |  |  |  
        | 0 |  | I | Negative(no reaction) | Normal | 170 (96.04%) |  
        | 1 | - < 5 | II | Normal (reactive) | Normal | 6 (3.38%) |  
        |  |  |  |  |  |  |  
        | 5 | - < 10 | III | Borderline | Normal | 1 (0.05%) |  
        | 10 - < 15 | IV | Positive | Abnormal | 0 (0.00%) |  
        | 15 - < 20 | V | Highly positive | Abnormal | 0 (0.00%) |  
        | > 20 | VI | Definite | Abnormal | 0 (0.00%) |  
        | Excluded | - | Cannot be judged | - | 3 (1.66%) |  |