TABLE 1.
Comparison of clinical parameters for virological cell culture, subgenomic RNA PCR, Ag rapid FIA, and Ag Gold.
| Assays and parameters | Positive | Negative | p-value* | |
| Cell culture | 15 | 48 | ||
| Viral RNA load (log10 RNA copies/mL) | Mean | 7.29 | 5.65 | 0.0003 |
| 95% CI (%) | 6.48–8.10 | 5.23–6.07 | ||
| SD | 1.45 | 1.44 | ||
| Days PSO | Mean | 3.20 | 6.87 | 0.020 |
| 95% CI (%) | 1.76–4.63 | 5.19–8.55 | ||
| SD | 2.59 | 5.77 | ||
| Subgenomic RNA | 22 | 41 | ||
| Viral RNA load (log10 RNA copies/mL) | Mean | 7.40 | 5.31 | <0.0001 |
| 95% CI (%) | 6.95–7.85 | 4.88–5.74 | ||
| SD | 1.01 | 1.35 | ||
| Days PSO | Mean | 3.59 | 7.29 | 0.009 |
| 95% CI (%) | 2.62–4.55 | 5.34–9.23 | ||
| SD | 2.17 | 6.16 | ||
| Ag rapid FIA | 38 | 25 | ||
| Viral RNA load (log10 RNA copies/mL) | Mean | 6.72 | 5.01 | <0.0001 |
| 95% CI (%) | 6.29–7.14 | 4.40–5.63 | ||
| SD | 1.28 | 1.49 | ||
| Days PSO | Mean | 7.76 | 4.84 | 0.0351 |
| 95% CI (%) | 5.02–10.49 | 3.48–6.19 | ||
| SD | 6.63 | 4.12 | ||
| Ag Gold | 23 | 31 | ||
| Viral RNA load (log10 RNA copies/mL) | Mean | 7.38 | 5.04 | <0.0001 |
| 95% CI (%) | 6.91–7.86 | 4.58–5.51 | ||
| SD | 1.09 | 1.27 | ||
| Days PSO | Mean | 3.26 | 8.54 | <0.0005 |
| 95% CI (%) | 2.03–4.48 | 6.22–10.86 | ||
| SD | 2.83 | 6.23 |
Viral RNA loads are expressed as log10 RNA copies/mL.
CI, confidence interval; SD, standard deviation; PSO, post symptom onset; FIA, fluorescent immunoassay.
*Two-sample t-test (two-tailed).
In the case of cell culture, subgenomic RNA, and Ag rapid FIA, the data set includes results from 63 serial respiratory samples obtained from SARS-CoV-2 positive subjects, while 54 samples were analyzed for Ag Gold assay.