Table 2.
Weighted SARS-CoV-2 seroprevalence estimates overall and by demographic characteristics, as assessed by a community survey of SARS-CoV-2 seroprevalence, and cumulative laboratory-confirmed COVID-19 cases reported through surveillance, Denver County, Colorado, July–August 2020 a
| Characteristic | Community seroprevalence survey | Cumulative COVID-19 cases reported through surveillance b | Estimated infection-to- reported case ratio c | |||
|---|---|---|---|---|---|---|
| Participants with SARS-CoV-2 antibodies, no. (%) | Participants without SARS-CoV-2 antibodies, no. (%) | Estimated seroprevalence, % (95% CI) | No. of cases | Incidence proportion, % b |
||
| Total | 23 (100.0) | 381 (100.0) | 8.0 (3.9-15.7) | 8142 | 1.1 | 7.1 (3.5-14.0) |
| Gender | ||||||
| Male | 13 (77.2) | 176 (47.4) | 12.4 (6.5-22.2) | 4185 | 1.1 | 10.8 (5.7-19.3) |
| Female | 10 (22.8) | 204 (52.2) | 3.6 (1.8-7.1) | 3957 | 1.1 | 3.3 (1.7-6.5) |
| Other (nonbinary) | 0 | 1 (0.4) | — | — | ||
| Age group, y | ||||||
| 0-17 | 2 (31.5) | 19 (18.0) | 13.1 (4.2-34.4) | 473 | 0.4 | 34.7 (11.1-91.2) |
| 18-49 | 18 (56.7) | 249 (53.8) | 8.4 (4.3-15.7) | 4733 | 1.2 | 7.0 (3.6-13.0) |
| 50-64 | 3 (11.8) | 66 (15.2) | 6.3 (1.8-19.9) | 1689 | 1.5 | 4.1 (1.2-12.9) |
| ≥65 | 0 | 47 (13.0) | 0 (0-7.6) | 1207 | 1.4 | — |
| Race and ethnicity | ||||||
| Non-Hispanic White | 11 (23.0) | 290 (57.7) | 3.3 (1.8-6.0) | 2137 | 0.5 | 6.2 (3.4-11.2) |
| Non-Hispanic Black | 2 (14.6) | 10 (8.4) | 13.1 (1.5-60.6) | 660 | 1.0 | 12.8 (1.5-59.3) |
| Hispanic | 9 (60.2) | 56 (26.6) | 16.4 (6.5-35.6) | 3808 | 1.8 | 9.2 (3.6-19.9) |
| Non-Hispanic Asian/Pacific Islander, American Indian/Alaska Native | 1 (2.2) | 15 (4.8) | 3.8 (0.3-37.1) | 330 | 1.0 | 3.8 (0.3-37.2) |
| Multiple races/ unknown d | 0 | 10 (2.6) | 0 (0-27.8) | 114 | 0.7 | — |
Survey respondent data weighted by selection probability and then calibrated by raking to more closely align with the demographic characteristics of the 2019 population distribution of Denver County.
Cumulative laboratory-confirmed COVID-19 cases reported to Denver Public Health as of July 22, 2020, the first day of enrollment in the community survey. Incidence proportion = (cumulative reported case counts/2019 estimated population) × 100, rounded. Denominator population overall and per subgroup according to 2019 census population estimates.13,14
Seroprevalence point estimate divided by cumulative reported incidence; range obtained by dividing upper and lower 95% CIs of seroprevalence estimate by cumulative reported incidence.
Multiple/other includes “unknown” race; surveillance data reflect only participants of multiple-race or other race categories and exclude 1093 cases reported with unknown race and ethnicity.