Volume 10, Number 6—June 2004
Dispatch
Antibody Prevalence of West Nile Virus in Birds, Illinois, 2002
Adam M. Ringia*
, Bradley J. Blitvich†, Hyun-Young Koo‡, Marshall Van de Wyngaerde*, Jeff D. Brawn‡, and Robert J. Novak*
, Bradley J. Blitvich†, Hyun-Young Koo‡, Marshall Van de Wyngaerde*, Jeff D. Brawn‡, and Robert J. Novak*Table 3
Differences in West Nile virus seropositivity in birds by age, region, and habitat using chi-square analysis, Illinois, 2002
| Comparison | Samples, n (% total) N = 1,784 | Antibody + (%)a | |
|---|---|---|---|
| Habitat |
Urban |
524 (29.4%) |
34 (6.49%)A |
| Natural |
1,121 (62.8) |
34 (3.03%)B |
|
| Captive |
139 (8.2%) |
26 (18.71%)C |
|
| χ 2 = 63.06 |
p < 0.0001 |
||
| Region |
Northern |
412 (23.1%) |
20 (4.85%)D |
| Central |
796 (44.6%) |
62 (7.79%)D |
|
| Southern |
576 (32.3%) |
12 (2.08%)E |
|
| χ 2 = 21.98 |
p < 0.0001 |
||
| Ageb |
Adult |
455 (25.5%) |
10 (2.2%)F |
| Hatch-year |
508 (28.5%) |
21 (4.1%)F |
|
| χ2 = 2.81 | p < 0.096 |
aLike superscripts indicate no difference in pairwise comparisons.
b821 of the 1,784 birds had no age recorded at time of collection. The remaining 963 were used for the age analysis.
