Table 2.
Frequency of secondary cases among the different sublineages
| Sublineage | 105 (n = 28) |
207 (n = 41) |
181 (n = 351) |
150 (n = 114) |
142 (n = 11) |
|---|---|---|---|---|---|
| Secondary cases, n (%)* | 5 (17.9) | 13 (31.7) | 68 (19.5) | 19 (17.4) | 1 (9.1) |
| OR (95%CI)† | 0.88 (0.33–2.37) | 2.02 (1.01–4.04) | 0.96 (0.62–1.49) | 0.83 (0.48–1.44) | 0.40 (0.05–3.17) |
| P value† | 0.801 | 0.048 | 0.862 | 0.504 | 0.387 |
| Number of clusters | 2 | 7 | 43 | 10 | 1 |
| Cluster size (median)‡ | 3–4 (3.5) | 2–6 (2) | 2–9 (2) | 2–5 (2) | 2 (2) |
*
The index case of each cluster is not counted in the number of secondary cases.
†
Each sublineage compared to all others.
‡
Cluster size includes the index case.
OR = odds ratio; CI = confidence interval.