Table 5.
Poisson regression analysis of risk factors of dogs seropositive for Rickettsia spp.
| Variable | Class | n | Seropositive | % | 95% CI% |
RR | 95% CIRR |
p | p-Wald | ||
|---|---|---|---|---|---|---|---|---|---|---|---|
| LL | UL | LL | UL | ||||||||
| Age (years) | 0–1 | 198 | 11 | 5.6 | 3.9 | 7.2 | 0.007 | ||||
| 2–7 | 166 | 27 | 16.3 | 13.4 | 19.1 | 2.9 | 1.5 | 5.9 | 0.003 | ||
| 8–15 | 35 | 2 | 5.7 | 1.8 | 9.6 | 1.0 | 0.2 | 4.6 | 0.971 | ||
| Scrotal edema | No | 395 | 38 | 9.6 | 1.0 | 99.0 | |||||
| Yes | 4 | 2 | 50.0 | 6.7 | 12.5 | 5.2 | 1.3 | 21.5 | 0.023 | ||
| Gait abnormalities | No | 337 | 28 | 8.3 | 7.8 | 51.1 | |||||
| Yes | 17 | 5 | 29.4 | 5.4 | 11.3 | 3.5 | 1.4 | 9.2 | 0.009 | ||
| Size | Small | 91 | 5 | 5.5 | 3.1 | 7.9 | 0.159 | ||||
| Medium | 300 | 33 | 11.0 | 9.2 | 12.8 | 2.0 | 0.8 | 5.1 | 0.148 | ||
| Large | 8 | 2 | 25.0 | 9.7 | 40.3 | 4.6 | 0.9 | 23.5 | 0.070 | ||
| Tick infestation indices | ≤1 | 188 | 11 | 5.9 | 4.1 | 7.6 | 0.003 | ||||
| 1.1–2.0 | 97 | 16 | 16.5 | 12.7 | 20.3 | 2.8 | 1.3 | 6.1 | 0.008 | ||
| ≥2.1 | 114 | 13 | 11.4 | 8.4 | 14.4 | 1.9 | 0.9 | 4.4 | 0.103 | ||
| Flea infestation indices | ≤1 | 267 | 20 | 7.5 | 5.9 | 9.1 | |||||
| 1.1–2.0 | 75 | 8 | 10.7 | 7.1 | 14.2 | 1.4 | 0.6 | 3.2 | 0.398 | 0.019 | |
| ≥2.1 | 57 | 12 | 21.1 | 15.7 | 26.5 | 2.8 | 1.4 | 5.7 | 0.005 | ||
| Breed | Mixed | 188 | 27 | 14.4 | 2.9 | 9.4 | |||||
| Purebred | 211 | 13 | 6.2 | 9.3 | 19.4 | 0.4 | 0.2 | 0.8 | 0.012 | ||
n: number of individuals +: number of seropositives %: seropositive percentage CI: confidence interval RR: rate ratio LL: lower limit UL: upper limit p: rate ratio probability p-Wald: Wald test probability.