Table 1.
Characteristics of Delta cases in Guangzhou, China from 21 May to 18 June 2021.
| Characteristics | No. (%) | Ct value, mean (SD) |
|---|---|---|
| Total | 153 | / |
| Incubation period (days)—median (IQR) | 4.00 (3.00, 6.00) | / |
| Serial time (days)—median (IQR) | 3.00 (2.00, 5.00) | / |
| Clustering | ||
| Household/community | 81 (52.94) | / |
| Restaurant | 41 (26.80) | / |
| School/workplace | 12 (7.84) | / |
| Other | 19 (12.41) | / |
| Generation | ||
| First | 1 (0.70) | 16.50 (/)a |
| Second | 2 (1.40) | 14.03 (1.67) |
| Third | 15 (10.49) | 21.08 (5.49) |
| Fourth | 37 (25.87) | 21.46 (6.06) |
| Fifth | 43 (30.07) | 24.34 (7.27) |
| Sixth | 43 (30.07) | 22.94 (5.68) |
| Seventh | 2 (1.40) | 31.72 (8.63) |
| Total | 143b | 22.62 (6.37) |
aThere was only one patient in this generation. bWe excluded 10 cases who were unable to trace their previous and next generations, and proportions of different generations were calculated by dividing the number by 143 instead of 153. IQR, interquartile range; SD, standard deviation; Ct, cycle threshold value.