TABLE 2.

Factors influencing the risk of Coxiella burnetii seropositivity among camel populations in southeastern Algeria.

Independent variable	B†	Standard error	Odds ratio	95% confidence interval (OR)	P
Constant	−1.654	0.899	-	-	0.066
Presence of ticks	0.790	0.363	2.203	1.081–4.490	0.030
Herd size	-	-	8.242	-	0.006
Small (< 20 head)	Reference	-	-	-	-
Medium (20–50 head)	0.318	0.782	1.374	0.297–6.368	0.685
Large (> 50 head)	1.495	0.755	4.459	1.015–19.591	0.048
Age class (years)	-	-	15.362	-	0.002
< 3 (n = 17)	Reference	-	-	-	-
3–7 (n = 57)	0.672	0.590	1.959	0.617–6.224	0.254
8–11 (n = 39)	0.811	0.624	2.250	0.662–7.641	0.194
> 11 (n = 71)	2.176	0.632	8.810	2.552–30.413	0.001

Model χ² 31.169 with 6 df.

Model-2 log likelihood 187.938.

χ² goodness of fit = 102.117; P value = 0.154.

^†, Logistic regression coefficient.