Table 3.
Distribution of Seroprevalence According to Geographical Area
| Area | ||||
|---|---|---|---|---|
| Capital | South DK, Zealand | Central DK, North DK | Total | |
| Nonreactive, n | 6325 | 7756 | 6147 | 20 228 |
| Reactive, n | 203 | 130 | 79 | 412 |
| Total, n | 6528 | 7886 | 6226 | 20 640 |
| Donor seroprevalence, % | ||||
| Unadjusted | 3.1 (2.7–3.6) | 1.6 (1.4–2.0) | 1.3 (1.0–1.6) | 2.0 (1.8–2.2) |
| Adjusted | 3.2 (2.1–3.9) | 1.4 (0.3–2.0) | 1 (0.0–1.5) | 1.9 (0.8–2.3) |
| Citizens aged 17–69 years, n | 1 268 550 | 1 349 455 | 1 279 208 | 3 897 213 |
| Expected seropositives, n | 40 908 (26 354–49 710) | 19 505 (4619–26 593) | 12 576 (0–19 226) | 72 828 (30 769–90 837) |
| Registered cases | ||||
| Confirmed cases, n | 2484 | 1169 | 962 | 4615 |
| Ratio of expected seropositives/confirmed cases | 16 (11–20) | 17 (4–23) | 13 (0–20) | 16 (7–20) |
A test sensitivity of 82.58% (75.68–88.20%) and a specificity of 99.54% (98.66–99.90%) were used in the adjustment of the seroprevalence percentage. Confirmed cases in each geographical area were defined as confirmed viral RNA reactives as of 6 April 2020 to allow for an extra 2-week lag time between detectable virus and antibody development [7].
Abbreviation: DK, Denmark.