TABLE. Estimated seroprevalence of SARS-CoV-2 immunoglobulin G (IgG) antibodies among a convenience sample of deidentified serum specimens from 19 facilities participating in the Influenza-like Illness Surveillance Network, by age group* — Oregon, May 11–June 15, 2020.
| Age group (yrs) | No. of samples tested | SARS-CoV-2 IgG-positive† |
|
|---|---|---|---|
| No. | % (95% CI) | ||
| 0–4 | 5 | 0 | 0 (0–52) |
| 5–17 | 24 | 0 | 0 (1–14) |
| 18–49 | 274 | 1 | 0.4 (0–2.0) |
| 50–64 | 211 | 1 | 0.5 (0–2.6) |
| 65–74 | 178 | 3 | 1.7 (0.3–4.8) |
| 75–84 | 144 | 3 | 2.1 (0.4–6.0) |
| ≥85 | 61 | 1 | 1.6 (0–8.8) |
| Total | 897 | 9 | 1.0 (0.2–1.8) |
Abbreviation: CI = confidence interval.
* Seroprevalence generally increased with age (chi-squared test for trend, p = 0.049).
† Abbott Architect Laboratories SARS-CoV-2 IgG immunoassay. Abbott Laboratories (Abbott Park, IL) reports a sensitivity of 96.8% at ≥14 days after a positive polymerase chain reaction test result and specificity of 99.1%–100%.