Univariate analysis of variables for SARS-CoV-2 antibodies in children of healthcare workers (Fisher’s exact test for categorical variables, Mann-Whitney U test for continuous variables). Number and per cent (%) with feature shown for categorical variables and median for continuous variables unless otherwise stated
| Variable | Complete data N (%) | Without SARS-CoV-2 antibodies N (%) | With SARS-CoV-2 antibodies N (%) | OR (95% CI) | P value |
| Median age (years) | 992 (100) | 10.1 (5.8) | 10.2 (6.9) | – | 0.481 |
| Aged 10 years and over | 992 (100) | 472 (51) | 36 (53) | 1.1 (0.6 to 1.8) | 0.802 |
| Male gender | 991 (99.9) | 468 (51) | 41 (60) | 1.5 (0.9 to 2.5) | 0.133 |
| Parents (patient contact) | 992 (100) | 789 (85) | 52 (76) | 0.6 (0.3 to 1.1) | 0.055 |
| Confirmed household contact | 960 (97) | 63 (7) | 30 (44) | 10.9 (6.1 to 19.6) | <0.0001 |
| Fever | 962 (97) | 102 (11) | 21 (31) | 3.5 (1.9 to 6.2) | <0.0001 |
| Gastrointestinal symptoms | 962 (97) | 31 (3) | 13 (19) | 6.6 (3.0 to 13.8) | <0.0001 |
| Headache | 962 (97) | 34 (4) | 12 (18) | 5.4 (2.4 to 11.4) | <0.0001 |
| Lethargy/fatigue | 962 (97) | 8 (1) | 9 (13) | 16.8 (5.5 to 51.9) | <0.0001 |
| Cough | 962 (97) | 90 (10) | 7 (10) | 1.03 (0.38 to 2.3) | 1.000 |
| Change in sense of smell/taste | 962 (97) | 7 (1) | 5 (7) | 10.0 (2.4 to 37.8) | <0.0008 |
| Myalgia/arthralgia | 962 (97) | 21 (2) | 5 (7) | 3.3 (0.94 to 9.4) | 0.031 |
| Sore throat | 962 (97) | 41 (5) | 5 (7) | 1.7 (0.5 to 4.4) | 0.367 |
| Shortness of breath | 962 (97) | 13 (1) | 3 (4) | 3.1 (0.6 to 11.8) | 0.098 |
| Coryza | 962 (97) | 27 (3) | 1 (1) | 0.5 (0.0 to 3.0) | 0.715 |
| Rash | 962 (97) | 10 (1) | 1 (1) | 1.3 (0.0 to 9,5) | 0.556 |
| Conjunctivitis | 962 (97) | 1 (0) | 0 (0) | 0.0 (0.0 to 508.7) | 1.000 |
Red type denotes those values that are statistically significant.