Volume 17, Number 6—June 2011
Research
Wild Birds and Increased Transmission of Highly Pathogenic Avian Influenza (H5N1) among Poultry, Thailand
Table A3
Prevalence of highly pathogenic avian influenza (H5N1) infection in wild birds, 2004–2007, Thailand *
Characteristic | No. infected birds | No. tested birds | Prevalence, % (95% CI) |
---|---|---|---|
Type of bird | |||
Migratory | 4 | 2,142 | 0.187 (0.01–0.21) |
Resident | 138 | 16,633 | 0.829 (0.66–0.94) |
Breeding visitor |
50 |
6,143 |
0.814 (0.61–0.99) |
Regions | |||
North | 13 | 5,321 | 0.24 (0.1–0.3) |
Central-Northwest | 77 | 4,510 | 1.71 (1.38–2.02) |
Central-North | 30 | 4,075 | 0.74 (0.49–0.91) |
Central-Central | 54 | 5,327 | 1.01 (0.78–1.22) |
Central-East | 1 | 1,462 | 0.07 (0.02–0.32) |
Central-Southeast | 21 | 2,083 | 1.01 (0.64–1.36) |
Central-Southwest | 3 | 1,713 | 0.18 (0–0.23) |
Northeast | 5 | 2,298 | 0.22 (0.05–0.35) |
South |
8 |
2,348 |
0.34 (0.11–0.49) |
Seasons, y | |||
Winter (January –February), 2004 | 29 | 366 | 7.92 (5.8–10.4) |
Summer (March–June), 2004 | 27 | 229 | 11.79 (8.7–15.8) |
Rainy (July–October), 2004 | 9 | 359 | 2.51 (1.51–4.32) |
Winter (November–December), 2004 and (January–February), 2005 | 19 | 1,027 | 1.85 (1.29–2.70) |
Summer (March–June), 2005 | 12 | 611 | 1.96 (1.26–3.15) |
Rainy (July–October), 2005 | 25 | 8,026 | 0.31 (0.22–0.43) |
Winter (November–December), 2005 and (January–February ), 2006 | 19 | 1,317 | 1.44 (1.00–2.10) |
Summer (March–June), 2006 | 7 | 3,768 | 0.19 (0.11–0.32) |
Rainy (July–October), 2006 | 17 | 4,528 | 0.38 (0.25–0.56) |
Winter (November–December), 2006 and (January–February), 2007 | 44 | 3,261 | 1.35 (1.06–1.73) |
Summer (March–June), 2007 | 4 | 3,032 | 0.13 (0.06–0.30) |
Rainy (July–October), 2007 | 0 | 2,338 | NA |
Winter (November–December), 2007 | 0 | 652 | NA |
*CI, confidence interval; NA, not applicable.