Table 3:

Proportion of household contacts who tested positive for SARS-CoV-2 antibodies by age group and symptom status of index participant

Age group; symptom statusHousehold contacts, all agesChild household contactsAdult household contactsOR (95% CI)†
n/N*% (95% CI)n/N*% (95% CI)n/N*% (95% CI)
Index participants, all ages
 Asymptomatic18/5135.3 (18.5–56.8)9/2142.9 (20.4–68.7)9/3030.0 (14.3–52.4)0.6 (0.3–1.4)
 Symptomatic221/43650.7 (44.2–57.1)121/22553.8 (46.0–61.4)100/21147.4 (40.2–54.7)0.9 (0.6–1.2)
 OR (95% CI)‡0.6 (0.2–1.4)0.7 (0.3–1.9)0.5 (0.2–1.3)
Child index participants
 Asymptomatic10/3429.4 (12.3–55.3)4/1136.4 (15.7–63.7)6/2326.1 (9.7–53.6)0.6 (0.3–1.3)
 Symptomatic62/16038.8 (28.3–50.4)19/5435.2 (21.3–52.1)43/10640.6 (30.0–52.1)1.4 (0.8–2.4)
 OR (95% CI)§0.7 (0.2–2.3)1.3 (0.4–4.4)0.6 (0.2–1.9)
Adult index participants
 Asymptomatic8/1747.1 (13.1–84.0)5/1050.0 (10.9–89.1)3/742.9 (11.0–82.0)0.9 (0.2–4.1)
 Symptomatic159/27657.6 (50.1–64.8)102/17159.6 (50.8–67.9)57/10554.3 (45.4–62.9)0.9 (0.6–1.3)
 OR (95% CI)0.7 (0.1–3.0)0.7 (0.1–3.6)0.7 (0.1–3.6)

  • 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 a child versus an adult household contact would become infected from the index participant in the given category.

  • ↵‡ Odds that a given type of household contact would become infected from an asymptomatic versus a symptomatic index participant of any age.

  • ↵§ Odds that a given type of household contact would become infected from an asymptomatic versus a symptomatic child index participant.

  • ↵ Odds that a given type of household contact would become infected from an asymptomatic versus a symptomatic adult index participant.