Table 2.
Risk factors associated with secondary household transmissions of SARS‐CoV‐2
| Risk factors | Household cases (n = 466) | Total contacts (n = 848) | SAR, % (95% CI) | cOR (95% CI) | aOR (95% CI) |
|---|---|---|---|---|---|
| Age of household contacts (years) | |||||
| <18 | 276 | 463 | 59.6 (55.1–64.1) | 1.5 (1.2–2.0) † | 1.4 (0.9–2.0) |
| ≥18 | 190 | 385 | 49.4 (44.1–54.4) | 1.0 | 1.0 |
| Sex of household contacts | |||||
| Male | 185 | 378 | 48.9 (43.8–53.9) | 1.0 | 1.0 |
| Female | 281 | 470 | 59.8 (55.3–64.2) | 1.7 (1.2–2.0) † | 1.6 (1.1–2.1) † |
| Household size (persons) | |||||
| <3 | 32 | 44 | 72.7 (59.5–85.9) | 2.3 (1.2–4.5) † | 1.2 (0.5–2.7) |
| ≥3 | 434 | 804 | 54.0 (50.6–57.4) | 1.0 | 1.0 |
| Relationship with household contacts | |||||
| Spousal | 94 | 128 | 73.4 (65.7–81.1) | 2.6 (1.7–3.9) † | 1.1 (0.7–2.0) |
| Non‐spousal | 372 | 720 | 51.7 (48.0–55.4) | 1.0 | 1.0 |
| Sleeping in the same room with the index case | |||||
| Yes | 249 | 378 | 65.9 (61.1–70.6) | 2.3 (1.7–3.0) † | 2.9 (2.0–4.2) † |
| No | 217 | 470 | 46.2 (41.7–50.7) | 1.0 | 1.0 |
| Age of the index case | |||||
| <18 | 34 | 164 | 20.7 (14.5–26.9) | 1.0 | 1.0 |
| ≥18 | 432 | 684 | 63.2 (59.6–66.8) | 6.5 (4.3–9.8) † | 7.0 (4.4–11.3) † |
| Sex of the index case | |||||
| Male | 335 | 556 | 60.3 (56.2–64.4) | 1.8 (1.4–2.5) † | 1.6 (1.2–2.3) † |
| Female | 131 | 292 | 44.9 (39.2–50.6) | 1.0 | 1.0 |
| Manifestation of the index case | |||||
| Asymptomatic | 93 | 217 | 42.9 (36.3–49.5) | 1.0 | 1.0 |
| Symptomatic | 373 | 631 | 59.1 (55.3–62.9) | 1.9 (1.4–2.6) † | 1.5 (1.1–2.2) † |
†
Statistical significance (P < 0.05). Total model accounted for 25.7% of the variance.
aOR, adjusted odds ratio; CI, confidence interval; cOR, crude odds ratio; SAR, secondary attack rate.