Table 5. Immunoglobulin G anti-West Nile virus prevalence in equines, by age, sex, breed, and group size, Camargue, France, 2000.
| Variable | OR estimatea | 95% CI |
|---|---|---|
| Age (years) | ||
| <1 | Ref | |
| 1–2 | 1.83 | 0.42 to7.99 |
| 3–5 | 1.39 | 0.32 to 5.98 |
| 6–10 | 1.13 | 0.26 to 4.86 |
| 11–15 | 1.25 | 0.29 to 5.41 |
| 16–20 | 1.24 | 0.28 to 5.43 |
| 21–25 | 1.20 | 0.26 to 5.48 |
| >25 | 1.24 | 0.25 to 6.15 |
| Sex | ||
| Mare | Ref. | |
| Gelding | 1.13 | 0.89 to 1.45 |
| Stallion | 1.18 | 0.88 to 1.58 |
| Breed | ||
| Pure breeds | 1.30 | 0.97 to 1.74 |
| Camargue | 1.40 | 1.08 to 1.82 |
| Ponies | 1.15 | 0.77 to 1.72 |
| Other | Ref. | |
| Group size | ||
| 1–2 | 2.18 | 1.60 to 2.96 |
| 3–6 | 1.81 | 1.31 to 2.52 |
| 7–25 | 1.09 | 0.77 to 1.53 |
| >25 | Ref. | |
aOR, odds ratio; 95% CI, 95% confidence intervals.