Table 2. Change in cycle threshold values from baseline to day 3 and association of the change with vaccination status for health-care workers with COVID-19, Brunei Darussalam, 15 February to 15 March 2022.
| Change in Ct values | No. of HCWs | Ct value at day 3a | |||
|---|---|---|---|---|---|
| 10–20 | 21–30 | > 30 | Negative | ||
| Ct value at day 0 | |||||
| 10–20 | 447 | 154 (34.5) | 279 (62.4) | 9 (2.0) | 5 (1.1) |
| 21–30 | 273 | 132 (48.4) | 109 (39.9) | 19 (7.0) | 13 (4.8) |
| ≥ 30 | 251 | 87 (34.7) | 41 (16.3) | 7 (2.8) | 116 (46.2) |
| Rapid antigen test positive | 150 | 71 (47.3) | 73 (48.6) | 1 (0.7) | 5 (3.3) |
| Total | 1121 | 444 | 502 | 36 | 139 |
|
Change in Ct values and
association with vaccination |
No. of HCWs | Ct valueb | P c | ||
| Day 0 | Day 3 | ||||
| Total | 975 | 20.9 (12.9) | 21.5 (7.3) | 0.74 | |
| Vaccination status | |||||
| 2 doses | 54 | 22.1 (11.3) | 22.35 (8.3) | 0.48 | |
| 3 doses | 921 | 20.9 (12.9) | 21.5 (7.1) | 0.56 | |
| Booster period | |||||
| Within < 1 month | 36 | 22.5 (15.9) | 24.7 (11.8) | 0.74 | |
| Within 1–3 months | 393 | 21.3 (14.4) | 21.9 (7.5) | 0.85 | |
| Within > 3 months | 546 | 20.7 (11.9) |
20.9 (6.9) | 0.41 | |
Ct: cycle threshold; HCW: health-care worker.
a Values are number (%).
b Values are median (interquartile range).
c P-values were calculated using the paired t-test.