Table 2.
Analysis of the transmission rates through close contacts by the symptomatic and asymptomatic cases of the coronavirus disease in Ningbo after removing all the cases associated with the super-spreader.
| Analysis | Close contacts, n | Infected | Uninfected, n | P value | |||
|
|
|
Symptomatic cases, n | Asymptomatic cases, n |
|
Combineda | Separateb | |
| Primary analysis of close contacts by symptomatic and asymptomatic cases | .84 (.37)d | .11 (.08) | |||||
|
|
Symptomatic cases | 1904 (97)c | 79 (28) | 15 (4) | 1810 (65) |
|
|
|
|
Asymptomatic cases | 146 | 3 | 3 | 140 |
|
|
|
|
Total | 2050 (97) | 82 (28) | 18 (4) | 1950 (65) |
|
|
| Subgroup analysis by different relationships with infected cases | <.001 | <.001 | |||||
|
|
Family | 268 | 37 | 10 | 221 |
|
|
|
|
Relatives | 400 | 13 | 6 | 381 |
|
|
|
|
Friends | 153 | 23 | 1 | 129 |
|
|
|
|
Coworkers | 57 | 2 | 0 | 55 |
|
|
|
|
Medical | 79 | 0 | 0 | 79 |
|
|
|
|
Others | 1093 | 7 | 1 | 1085 |
|
|
|
|
Total | 2050 | 82 | 18 | 1950 |
|
|
| Subgroup analysis by different types of contact with infected cases | <.001 | <.001 | |||||
|
|
Daily activities | 1048 | 69 | 14 | 965 |
|
|
|
|
Transportation | 167 | 1 | 2 | 164 |
|
|
|
|
Medical contact | 297 | 4 | 0 | 293 |
|
|
|
|
Other contact | 538 | 8 | 2 | 528 |
|
|
|
|
Total | 2050 | 82 | 18 | 1950 |
|
|
aCombined means P values were obtained by pooling the numbers of symptomatic and asymptomatic cases together.
bSeparate means P values were obtained by separating the numbers of symptomatic and asymptomatic cases.
cThe numbers in the parentheses are associated with the super-spreader.
dP values in the parentheses were obtained when including the cases associated with the super-spreader.