Table 2.
Baseline variables related to preventive measures and secondary attack rates of household contacts of COVID-19 cases (Spain, May 2022 until July 2023).
| Household contacts | Infections | SAR | p-value | |
|---|---|---|---|---|
| n (%) | n | % | ||
| Quarantine | 0.319 | |||
| No | 131 (76.2) | 66 | 50.4 | |
| Yes | 41 (23.8) | 17 | 41.5 | |
| Mask use and type | 0.926 | |||
| No | 103 (59.9) | 50 | 48.5 | |
| Yes | 69 (40.1) | 33 | 47.8 | |
| Surgical masks | 34 (49.3) | 13 | 38.2 | 0.284 |
| FFP2 masks | 33 (47.8) | 19 | 57.6 | |
| Cloth masks | 2 (2.9) | 1 | 50.0 | |
| Hand washing | 0.196 | |||
| 0 time/day | 0 | 0 | 0.0 | |
| 1–2 times/day | 16 (9.3) | 9 | 56.3 | |
| 3–4 times/day | 57 (33.1) | 22 | 38.6 | |
| >4 times/day | 99 (57.6) | 52 | 52.5 | |
| Hydroalcoholic solution | 0.500 | |||
| 0 time/day | 99 (57.6) | 46 | 46.5 | |
| 1–2 times/day | 21 (12.2) | 13 | 61.9 | |
| 3–4 times/day | 18 (10.5) | 7 | 38.9 | |
| >4 times/day | 34 (19.8) | 17 | 50.0 | |
| Social distance | 0.070 | |||
| No | 91 (52.9) | 51 | 56.0 | |
| Yes | 80 (46.5) | 32 | 40.0 | |
| Unknown | 1 (0.6) | 0 | 0.0 | |
| Ventilation | 0.299 | |||
| No | 1 (0.6) | 1 | 100.0 | |
| Yes | 171 (99.4) | 82 | 48.0 | |
| 1 time/day | 29 (16.9) | 14 | 48.3 | 0.583 |
| ≥2 times/day | 142 (82.6) | 68 | 47.9 | |
| Prior Covid-19 infection | 0.017 | |||
| No | 100 (58.1) | 56 | 56.0 | |
| Yes | 72 (41.9) | 27 | 37.5 | |
| COVID-19 vaccination status | ||||
| Unvaccinated | 4 (2.3) | 2 | 50.0 | 0.090 |
| Vaccinated with 1 dose | 7 (4.1) | 3 | 42.9 | |
| Vaccinated with 2 doses | 36 (20.9) | 13 | 36.1 | |
| Vaccinated with 3 doses | 95 (55.2) | 44 | 46.3 | |
| Vaccinated with 4 doses | 30 (17.4) | 21 | 70.0 |
SAR: secondary attack rate.