TABLE 3.
Determinants of PCR-detected A. phagocytophilum infection prevalence in ticks molted from engorged immature I. ricinus collected from study sheep
| Factor | OR (95% CI)a | Wald Z (P)b |
|---|---|---|
| Tick collected from sheep pre- vs postinfection | 13.63 (1.65-112.17) | 2.427 (0.015) |
| Tick molted from engorged nymph vs larva | 5.75 (1.72-19.29) | 2.833 (0.005) |
| Sheep carrying 4 or more adult ticks vs sheep carrying 3 or fewer | 8.50 (1.46-49.90) | 2.377 (0.017) |
| No. of infected cells per ml of blood | 1.75 (0.96-3.19) | 1.827 (0.068) |
| Interaction of no. of feeding nymphs on sheep carrying 4 or more adult ticks | 0.70 (0.49-0.98) | −1.968 (0.049) |
| Intercept | 0.01 (0.01-0.10) | −3.022 (0.003) |
a
CI, confidence interval.
b
Wald Z values represent parameter estimates divided by their asymptotic standard errors.