TABLE 1.
Serial testing studies of interferon-gamma release assays in health care workers (HCWs) in low and intermediate incidence countries
| Author (reference), year, country | Duration between testing |
Conversion, n/N (%)
|
IGRA reversions*, n/N (%) | |
|---|---|---|---|---|
| Tuberculin skin test | IGRA* | |||
| Joshi et al (15), 2012, USA | 2 to 30 days | N/A | N/A | 18/45 (40) |
| Rafiza et al (16), 2012, Malaysia | 1 year | N/A | 69/703 (9.8) | 14/59 (23.7) |
| Fong et al (17), 2012, USA | 1 year or 1 to 6 months for repeat of positive IGRA | N/A | 52/1857 (2.8) | 8/10 (80)† |
| Torres Costa et al (18), 2011, Portugal | 1 year | 61/199 (30.7) Reversion rates: 4/188 (2.1) | 51 /462 (11) | 46/208 (22.1) |
| Schablon et al (19), 2010, Germany | High-risk HCWs tested annually, all others evaluated every other year | N/A | 15/245 (6.1) | 13/42 (32.6) |
| Ringshausen et al (20), 2010, Germany | 18 weeks | N/A | 3/162 (1.9) | 6/18 (33.3) |
| Park et al (21), 2010, South Korea | 1 year | N/A | 14/244 (5.7) | N/A |
| Lee et al (22), 2009, South Korea | 1 year | 16/75 (21.3) | 21/146 (14.4) | N/A |
| Chee et al (23), 2009, Singapore | 1 year | 0/18 (Note: denominator includes only baseline concordant positives) | 9/182 (4.9) | N/A |
| Yoshiyama et al (24), 2009, Japan | 2 and 4 years | N/A | 5/277 (1.8) | 13/32 (41) |
| Pollock et al (25), 2008, USA | 1 to 7 months | N/A | 2/43 (4.6). Selected HCWs at ‘increased risk’ and negative at baseline | N/A |
*
All conversions/reversions using simple negative/positive;
†
Testing was performed among individuals with positive QuantiFERON-TB (Cellestis Ltd, Australia) results close to the cut-off point. IGRA Interferon-gamma release assay; N/A Not available