Table 3.
Relationship between PCR cycle threshold and rapid antigen test reactivity.
| Symptomatic Subjects | ||
|---|---|---|
| PCR RESULTS | ||
| POS (average ct = 20) | NEG | |
| Ag Pos | n = 251 | n = 7 |
| Ct < 30, n = 243, X = 20 | ||
| Ct > 30, n = 8, X = 33 | ||
| Ag Neg | n = 54 | n = 573 |
| Ct < 30, n = 34, X = 26 | ||
| Ct > 30, n = 20, X = 34 | ||
| Asymptomatic Subjects | ||
| PCR RESULTS | ||
| POS (average ct = 23) | NEG | |
| Ct < 30, n = 6, X = 23 | ||
| Ct > 30, n = 0 | ||
| Ag Neg | n = 13 | n = 1525 |
| Ct < 30, n = 1, X = 18 | ||
| Ct > 30, n = 12, X = 35 | ||
Data presented in Table 3 are stratified according to PCR cycle thresholds (ct). Subjects that tested PCR-positive and Ag-negative (in bold) were divided into two groups: <30 ct and >30 ct and mean (X) ct values were calculated.