Table 2.
Comparison between contact patients who subsequently developed SARS-CoV-2 infection and those who did not
| Characteristics | Positive contacts (n=10)# | Negative contacts (n=79) | P-value* |
|---|---|---|---|
| Age (years), median (IQR) | 73.5 (59.0-82.5) | 70.0 (57.0-76.0) | 0.21 |
| Male, n (%) | 6 (60.0) | 52 (65.8) | 0.73 |
| On-site isolation, n (%) | 0 (0.0) | 26 (32.9) | 0.03 |
| Cancer, n (%) | 6 (60.0) | 11 (16.4) | 0.006 |
| Length of stay (days), median (IQR) | 13.5 (12.0-21.0) | 8.0 (3.0-15.0) | 0.01 |
| Ward, n (%) | 0.88 | ||
| Surgery | 1 (10.0) | 8 (10.1) | |
| Medicine | 6 (60.0) | 53 (67.1) | |
| ICU | 3 (30.0) | 18 (22.8) | |
| Four-bed room, n (%) | 5 (50.0) | 40 (50.6) | 1.0 |
| Adjacent bed to index, n (%) | 8 (80.0) | 48 (60.8) | 0.31 |
| Duration of contact (hours), median (IQR) | 14.7 (6.3-66.3) | 17.7 (9.0-26.8) | 0.93 |
| Ct-value index, median (IQR) | 21.3 (15.4-23.1) | 27.9 (23.4-32.5) | 0.001 |
# The three positive contacts, for which a direct transmission was ruled out through WGS, were not included in this table
* χ2 and Fisher exact test for categorical variables and Mann-Whitney U test for continuous variables
IQR: interquartile range; ICU: intensive care unit; Ct-value: cycle threshold value (number of cycles required for the fluorescent signal to cross the threshold in a real time PCR assay; Ct levels are inversely proportional to the amount of target nucleic acid in the sample, i.e. the lower the Ct level the greater the viral load)