Table 3.
The Ratio of Confirmed SARS-CoV-2 Cases to Estimated Number of SARS-CoV-2 Seropositives
| Measure of SARS-CoV-2 Case Numbers | Value |
|---|---|
| Estimated number of seropositives weeks 9 to 40, 2020 | |
| Unadjusted, n | 97172 |
| Adjusted, n (95% CI)a | 82523 (50377–100413) |
| Estimated number of seropositives week 41, 2020 to week 4, 2021 | |
| Unadjusted, n | 189780 |
| Adjusted, n (95% CI)a | 197048 (183514–215328) |
| Confirmed cases by RT-PCR, n | |
| Weeks 9 to 40, 2020 | 23691 |
| Week 41, 2020 to week 4, 2021 | 126023 |
| Ratio of confirmed cases to estimated number of seropositives, weeks 9 to 40, 2020 | |
| Unadjusted | 0.24 (.22–.26) |
| Adjusted (95% CI)a | 0.29 (.24–.47) |
| Ratio of confirmed cases to estimated number of seropositives, week 41, 2020 to week 4, 2021 | |
| Unadjusted | 0.66 (.61–.73) |
| Adjusted (95% CI)a | 0.64 (.59–.69) |
The ratio of confirmed cases to estimated number of seropositives, weeks 9 to 40, 2020 and week 41, 2020 to week 4, 2021. The number of estimated seropositives and RT-PCR–positive cases used in the estimation were additionally specified.
Abbreviations: CI, confidence interval; RT-PCR, real-time polymerase chain reaction; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.
Seroprevalence adjusted for assay sensitivity and specificity.