Table 5.
Generalized estimating equation negative binomial regression model for the prediction of collection rates for life stages of Amblyomma americanum in relation to elevation and forest characteristics in southwestern Virginia, USA, from February 2018 to January 2019
| Tick Species, life stage | Variable | Coefficient (SE) | RR (95% CI) | P |
|---|---|---|---|---|
| Amblyomma americanum, All life stages | Season (warm vs. coola) | 3.52 (0.34) | 33.66 (17.36, 65.26) | <0.001 |
| Elevation (m) | −0.85 (0.38) | 0.43 (0.20, 0.89) | 0.024 | |
| Canopy (%) | −0.28 (0.11) | 0.75 (0.60, 0.94) | 0.013 | |
| Basal Area (sq ft per ac) | 0.04 (0.01) | 1.04 (1.02, 1.06) | 0.001 | |
| Constant | 22.97 (10.54) | NA | 0.029 | |
| Amblyomma americanum, Adult | Season (warm vs. coola) | 2.32 (0.46) | 10.13 (4.13, 24.83) | <0.001 |
| Elevation (m) | −0.78 (0.35) | 0.46 (0.23, 0.91) | 0.026 | |
| Trees per acre | −0.60 (0.14) | 0.55 (0.42, 0.72) | <0.001 | |
| Constant | 3.85 (1.72) | NA | 0.025 | |
| Amblyomma americanum, Nymph | Season (warm vs. coola) | 5.86 (0.68) | 351.37 (92.90, 1329.04) | <0.001 |
| Elevation (m) | −0.92 (0.41) | 0.40 (0.18, 0.88) | 0.024 | |
| Canopy (%) | −0.28 (0.14) | 0.76 (0.58, 0.99) | 0.045 | |
| Basal Area (sq ft per ac) | 0.04 (0.01) | 1.04 (1.02, 1.07) | <0.001 | |
| Constant | 19.08 (12.33) | NA | 0.122 | |
| Amblyomma americanum, Larvae | Season (warm vs. coola) | 1.62 (0.50) | 5.04 (1.90, 13.34) | 0.001 |
| Elevation (m) | −0.78 (0.32) | 0.46 (0.25, 0.86) | 0.015 | |
| Canopy (%) | −0.29 (0.12) | 0.75 (0.60, 0.81) | 0.012 | |
| Trees per acre | −0.34 (0.08) | 0.70 (0.60, 0.81) | <0.001 | |
| Constant | 29.96 (10.92) | NA | 0.006 |
SE = standard error. RR = relative rate. CI = confidence interval. NA = not applicable.
a indicates reference category.