Table 1

Definitions of classifications used for LTBI, hepatitis B, hepatitis C and HIV

(number screened)
Classification statusDefinitionNumber classified (%*)
Latent tuberculosis
PositiveTB-specific antigen response >0.35 IU/mL and no evidence of active disease on clinical assessment81 (16.5)
NegativeTB-specific antigen response <0.35 IU/mL408 (83.1)
Hepatitis B
CurrentHBsAg positive, anti-HBc negative, anti-HBs negative7 (1.4)
PastHBsAg negative, anti-HBc positive, anti-HBs positive (confirmed; n=43)
HBsAg negative, anti-HBc positive, anti-HBs negative (probable past; n=8)
51 (10.4)
Immune probably through vaccination§HBsAg negative, anti-HBc negative, anti-HBs positive140 (28.7)
Non-immuneHBsAg, anti-HBc, anti-HBs negative291 (59.5)
Hepatitis C
CurrentAnti-HCV positive and HCV RNA positive51 (10.4)
PastAnti-HCV positive, HCV RNA negative and RIBA positive13 (2.7)
Uncertain historyAnti-HCV positive or equivocal, HCV RNA negative and no RIBA or insufficient sample for testing3 (0.6)
NegativeAnti-HCV and HCV RNA negative424 (86.4)
SeropositiveAnti-HIV/p24 antigen positive5 (1.0)
SeronegativeAnti-HIV/p24 antigen positive486 (99.0)
  • *Denominator for each percentage is number screened, in first column.

  • †Two missing LTBI results as indeterminate and two missing hepatitis B test results due to insufficient sample for testing.

  • ‡Further details available from Cellestis, Australia, including interpretation of controls.34

  • §Median anti-HBs level was 195 IU/L (IQR 46–945).

  • ¶Three subjects had equivocal anti-HBc and negative anti-HBe.

  • HBc, hepatitis B core; HBe, hepatitis B envelope; HBs, hepatitis B surface; HBsAg, hepatitis B surface antigen; HCV, hepatitis C virus; LTBI, latent tuberculosis infection; RIBA, Recombinant ImmunoBlot Assay.