|
Characteristics
|
New TST positives
|
Previously defined as TST positives
|
Total
|
|---|
|
TST positives among exposed (%)
|
27/155 (17%)
|
15/155 (10%)
|
42/155 (27%)
|
|
T-SPOT.TB
-positives among exposed (%)
|
3/155 (2%)
|
2/155 (1%)
|
5/155 (3%)
|
|
T-SPOT.TB
-positives among TST positives (%)
|
3/27 (11%)
|
2/15 (13%)
|
5/42 (12%)
|
- Table 2 depicts concordance between tuberculin skin test (TST) and T-SPOT.TB results. Results in absolute numbers (percentages in brackets) from post-exposure screening of 155 health care workers (HCWs) and 48 healthy controls, 2005–2007. During childhood all participants were either BCG-immunized or had a naturally positive TST. The definition of a positive TST (Mantoux) was an increase of ≥ 10 mm, or of ≥ 15 mm if previous TST status was unknown (in concordance with the national guidelines). The exposed HCWs were also tested with T-SPOT.TB, an interferon-gamma release assay (IGRA). Some HCWs had been defined as TST positives during previous post-exposure screenings (15) while others were defined as TST positives during the current study (27).
