Proportion of household contacts testing positive for SARS-CoV-2 antibodies by age of index participant
| Group; age, yr | Household contact, all ages | Child household contacts | Adult household contacts | OR (95% CI)† | |||
|---|---|---|---|---|---|---|---|
| n/N* | % (95% CI) | n/N* | % (95% CI) | n/N* | % (95% CI) | ||
| Index participants, all ages | 239/487 | 49.1 (42.9–55.3) | 130/246 | 52.8 (45.3–60.2) | 109/241 | 45.2 (38.4–52.2) | 0.8 (0.6–1.1) |
| Child index participants | 72/194 | 37.1 (27.7–47.6) | 23/65 | 35.4 (23.1–50.0) | 49/129 | 38.0 (28.6–48.4) | 1.2 (0.8–2.0) |
| ≤ 3 | 6/32 | 18.8 (7.0–41.3) | 1/11 | 9.1 (1.0–50.3) | 5/21 | 23.8 (7.3–55.5) | 3.2 (0.2–48.0) |
| 4–11 | 47/113 | 41.6 (29.0–55.4) | 17/40 | 42.5 (26.7–60.0) | 30/73 | 41.1 (28.4–55.1) | 1.0 (0.6–1.7) |
| 12–17 | 19/49 | 38.8 (20.8–60.4) | 5/14 | 35.7 (12.4–68.5) | 14/35 | 40.0 (23.3–59.3) | 1.6 (0.7–3.7) |
| Adult index participants | 167/293 | 57.0 (49.5–64.2) | 107/181 | 59.1 (50.3–67.4) | 60/112 | 53.6 (44.8–62.1) | 0.9 (0.6–1.3) |
| 18–29 | 17/32 | 53.1 (32.3–72.9) | 7/15 | 46.7 (26.0–68.6) | 10/17 | 58.8 (34.0–79.9) | 1.6 (0.8–3.3) |
| 30–49 | 130/230 | 56.5 (47.7–64.9) | 90/152 | 59.2 (49.4–68.3) | 40/78 | 51.3 (40.7–61.8) | 0.8 (0.6–1.2) |
| ≥ 50 | 20/31 | 64.5 (43.9–80.9) | 10/14 | 71.4 (34.9–92.1) | 10/17 | 58.8 (39.0–76.1) | 0.7 (0.2–2.8) |
Note: CI = confidence interval, OR = odds ratio.
↵* n/N = number of household contacts with SARS-CoV-2 antibodies in households in which the index participant was in a specified age category/total number of household contacts in households in which the index participant was in specified age category.
↵† Odds that an adult versus a child in the household would become infected from index participant of a given age.