Table 2.
SARS-CoV-2 antibody prevalence by age, region, and sex
| Variables | n (%) | Screened positivity (n = 32)1 |
Confirmed positivity (n = 25)2 |
Capital area cumulative incidence (~1/16/2021)4 | |||||
|---|---|---|---|---|---|---|---|---|---|
| No. of positive detection | Prevalence | Estimated prevalence3 | No. of positive detection | Prevalence | Estimated prevalence | ||||
| Entire capital area | 4,942 (100) | 32 | 0.65 (0.46, 0.91) | 0.60 (0.42, 0.85) | 25 | 0.51 (0.34, 0.75) | 0.47 (0.31, 0.70) | 0.18 | |
| Age (yr) | |||||||||
| 19-29 | 898 (18.2) | 3 | 0.33 (0.11, 0.98) | 0.29 (0.09, 0.92) | 3 | 0.33 (0.11, 0.98) | 0.29 (0.09, 0.92) | 0.17 | |
| 30-39 | 855 (17.3) | 7 | 0.82 (0.40, 1.68) | 0.69 (0.32, 1.51) | 4 | 0.47 (0.18, 1.20) | 0.40 (0.14, 1.10) | 0.16 | |
| 40-49 | 982 (19.9) | 2 | 0.20 (0.06, 0.74) | 0.18 (0.05, 0.70) | 2 | 0.20 (0.06, 0.74) | 0.18 (0.05, 0.70) | 0.15 | |
| 50-59 | 967 (19.6) | 8 | 0.83 (0.42, 1.62) | 0.78 (0.39, 1.56) | 7 | 0.72 (0.35, 1.49) | 0.69 (0.33, 1.44) | 0.19 | |
| 60-69 | 691 (14.0) | 6 | 0.87 (0.40, 1.88) | 0.89 (0.41, 1.94) | 4 | 0.58 (0.23, 1.48) | 0.61 (0.23, 1.56) | 0.23 | |
| ≥70 | 549 (11.1) | 6 | 1.09 (0.50, 2.36) | 1.00 (0.45, 2.24) | 5 | 0.91 (0.39, 2.11) | 0.79 (0.32, 1.95) | 0.23 | |
| Sex | |||||||||
| Male | 2,454 (49.7) | 15 | 0.61 (0.37, 1.01) | 0.56 (0.34, 0.95) | 10 | 0.41 (0.22, 0.75) | 0.38 (0.20, 0.71) | 0.18 | |
| Female | 2,488 (50.3) | 17 | 0.68 (0.43, 1.09) | 0.63 (0.39, 1.03) | 15 | 0.60 (0.37, 0.99) | 0.55 (0.33, 0.93) | 0.18 | |
| Region | |||||||||
| Gyeonggi Province | 2,882 (58.3) | 25 | 0.87 (0.59, 1.28) | 0.87 (0.59, 1.28) | 20 | 0.69 (0.45, 1.07) | 0.67 (0.45, 1.08) | 0.15 | |
| Seoul | 1,681 (34.0) | 7 | 0.42 (0.20, 0.86) | 0.42 (0.20, 0.86) | 5 | 0.30 (0.13, 0.69) | 0.30 (0.13, 0.69) | 0.24 | |
| Incheon | 379 (7.7) | 0 | - | - | 0 | - | - | 0.14 | |
Values are presented as % (95% confidence interval).
SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; PRNT, plaque reduction neutralization test.
1
Screened positivity was based on the test results using Elecsys anti-SARS-CoV-2 (Roche).
2
Confirmed positivity was based on the serial test results using GenScript or PRNT.
3
Estimation with sampling weight using the population of resident registration.
4
The cumulative incidence rate in the capital area was calculated using the cumulative number of confirmed people aged ≥19 years until January 16, 2021 as a numerator and the resident registration population in February 2021 as the denominator.