Table 1.
Infection status versus age, sex, migration, exposure time, and Mantoux status
| Characteristics | New TST positives HCWs (n = 27) |
Previously defined as TST positive HCWs (n = 15) |
TST negatives HCWs (n = 113) |
Healthy Controls (n = 48) |
|---|---|---|---|---|
| Age (years, mean (range)) | 38.9 (22–65) | 38.9 (22–65) | 38.9 (22–65) | 41.4 (20–67) |
| Sex (female/male) | 22/5 | 12/3 | 98/15 | 33/15 |
| Migration | ||||
| 1. Born in a low-endemic area | 25 | 12 | 101 | 48 |
| 2. Worked in a high-endemic area > 6 months | 0 | 0 | 6 | |
| 3. Born in a high-endemic area | 2 | 2 | 6 | |
| Exposure time (≤ 8 h/> 8 h) | 20/7 | 10/4 | 84/29 | |
| Mantoux (mm) before exposure (median) | 8 | 6/13 | 5/4 | |
| Mantoux (mm) after exposure (median) | 19 | 6/6 | ||
| Vesiculous Mantoux after exposure | 8 |
*Results in absolute numbers 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 tuberculin skin test (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). Some HCWs had been defined as TST positive during previous post-exposure screenings (15), while others were defined as infected during the current study (27).