Table 3.
Epidemic characteristics, mean generation time, and R0 in two models by HPAI subtype H5N1, H5N8, and H5N6.
| Subtype | Average | Average | Cases | Chicken (%) | Duck (%) | Etc. (%) | Mean generation | R0 by EG Method | R0 by ML Method |
|---|---|---|---|---|---|---|---|---|---|
| epidemic days | number of farms | per day | time (days) | (95% CI) | (95% CI) | ||||
| H5N1 | 86.0 | 69.0 | 0.802 | 41.7 (60.4) | 26.0 (37.7) | 2.0 (2.9) | 4.80 (4.23–5.38) | 1.96 (1.48–2.39 | 1.69 (1.10–2.28) |
| H5N8 | 143.8 | 107.8 | 0.750 | 23.5 (21.8) | 80.0 (74.2) | 4.3 (3.9) | 7.58*(6.63–8.46) | 1.49 (1.19–1.79) | 1.60 (0.97–2.23) |
| H5N6 | 108.0 | 181.0 | 1.676 | 100.0 (55.2) | 77.0 (42.5) | 4.0 (2.2) | 5.09 (4.44–5.74) | 1.14 (0.76–1.51) | 1.49 (0.94–2.04) |
EG, exponential growth; ML, maximum likelihood estimation; CI, confidence interval.
*
Mean generation time of subtype H5N8 is significantly longer than subtype H5N1 (P = 0.03).