Table 2 Within-flock reproductive ratio (R0) estimated in 924 IPs reported during Period I (i.e. pre-vaccination period) and in 106 IPs reported during Period II (i.e. vaccination period).
Infected Premise Species/Size | Reproductive number, R 0 (Mean; 95%CI; N) | Â |
|---|---|---|
| Â | Pre-vaccination IPs | Post-vaccination IPs |
All IP's | 1.99; 1.87, 2.10; 924 | 1.17; 1.09 - 1.25; 106 |
Chicken flocks only | Â | Â |
Pooled | 2.16; 1.94, 2.39; 297 | 1.07; 0.90, 1.23; 12 |
1-50 heads | 2.03; 1.71, 2.36; 58 | 1.04; 0.76, 1.32; 7 |
51-200 heads | 1.90; 1.55, 2.25; 77 | 0.80; 0.68, 1.11; 2 |
201-500 heads | 2.28; 1.8, 2.74; 74 | NA |
501-1,000 heads | 1.92; 1.33, 2.50; 46 | 1.02; 0.87, 1.24; 1 |
1,001-1,500 heads | 2.77; 1.45, 4.09; 21 | 1.34;1.03, 1.71; 2 |
>1,500 heads | 2.86; 1.40, 4.31; 21 | NA |
Duck flocks only | Â | Â |
Pooled | 1.96; 1.81, 2.11; 560 | 1.21; 1.12, 1.31; 90 |
1-50 heads | 2.02; 1.53, 2.50; 27 | 0.96; 0.72, 1.20; 18 |
51-200 heads | 1.85; 1.55, 2.14; 96 | 1.36; 1.12, 1.59; 23 |
201-500 heads | 2.16; 1.84, 2.48; 152 | 1.09; 0.95, 1.24; 18 |
501-1,000 heads | 1.90; 1.61, 2.19; 154 | 1.27; 1.12, 1.41; 18 |
1,001-1,500 heads | 1.92; 1.48, 2.36; 76 | 1.46; 1.02, 1.90; 7 |
>1,500 heads | 1.55; 1.18, 1.92; 55 | 1.31; 1.01, 1.61; 6 |
Mixed poultry species | Â | Â |
Pooled | 1.91; 1.53, 2.29; 67 | 1.01; 0.74, 1.23; 4 |
1-50 heads | 3.20; 2.19, 4.21; 8 | 1.04; 0.83, 1.25; 3 |
51-200 heads | 1.61; 1.24, 1.97; 25 | NA |
201-500 heads | 1.28; 1.10, 1.45; 22 | 0.92; 0.74, 1.31; 1 |
501-1,000 heads | 2.45; 0.86, 4.04; 11 | NA |
1,001-1,500 heads | 1.47; 1.17, 1.85; 1 | NA |
>1,500 heads | NA | NA |