Table 2.
Cycle Threshold (CT) Values for 1,213 Specimens Reported as Positive or Presumptive for SARS-CoV-2
| Target 1 (ORF1) | Target 2 (E-Gene) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Group | No. of Specimens | Mean CT | Median CT | IQR | P Valuea | Mean CT | Median CT | IQR | P Valuea |
| All specimens | 1,213 (100%) | 24.57 | 25.02 | 20.35-29.99 | — | 26.29 | 25.93 | 21.14-31.73 | — |
| Age <10 y | 20 (1.6%) | 25.95 | 24.02 | 21.59-30.82 | .568 | 26.71 | 24.3 | 22.19-31.87 | .764 |
| Age 10-19 y | 33 (2.7%) | 22.78 | 21.87 | 19.09-27.00 | .067 | 24.54 | 22.04 | 19.22-29.66 | .114 |
| Age 20-29 y | 150 (12.3%) | 24.59 | 24.76 | 20.17-29.31 | .984 | 26.16 | 25.55 | 20.79-30.30 | .818 |
| Age 30-39 y | 174 (14.3%) | 24.74 | 24.98 | 20.65-30.00 | .881 | 26.2 | 25.93 | 21.06-31.19 | .872 |
| Age 40-49 y | 231 (19.0%) | 24.84 | 25.02 | 20.61-30.05 | .552 | 26.51 | 25.12 | 20.66-30.85 | .624 |
| Age 50-59 y | 194 (16.0%) | 24.88 | 25.66 | 20.02-29.82 | .779 | 26.05 | 26.05 | 20.27-31.09 | .631 |
| Age 60-69 y | 161 (13.3%) | 24.54 | 25.92 | 20.33-30.03 | .610 | 26.76 | 26.67 | 21.18-32.22 | .362 |
| Age 70-79 y | 126 (10.4%) | 25.05 | 25.62 | 21.07-30.34 | .230 | 27.09 | 26.28 | 22.09-32.26 | .170 |
| Age 80-89 y | 86 (7.1%) | 22.80 | 22.42 | 19.29-26.67 | .028 | 25.02 | 23.86 | 20.22-29.31 | .068 |
| Age >89 y | 38 (3.1%) | 23.81 | 24.62 | 19.59-28.96 | .888 | 26.48 | 27.61 | 22.25-32.12 | .849 |
IQR, interquartile range.
a P values are based on a comparison of mean CT values of each age group vs the mean of all CT values for Target 1 or Target 2. Bold value indicates significance, P < .05.