Ecological drivers of dog heartworm transmission in California

Parasites & Vectors

Table 2 Effect of mosquito predictors on dog heartworm cases

	Northern California			Central California			Southern California
	Coef. estimate	Std. error	p-value	Coef. estimate	Std. error	p-value	Coef. estimate	Std. error	p-value
Ae. aegypti	−69.392	44.763	0.124	7.697	2.899	0.010*	26.229	13.939	0.070
Ae. albopictus	−1368.483	486.612	0.006*	NA	NA	NA	35.1330	12.444	0.008*
Ae. sierrensis	4.607	12.626	0.716	4.003	1.951	0.045*	−20.068	9.353	0.040*
Ae. vexans	12.912	17.754	0.469	3.258	1.869	0.087	−19.892	8.554	0.027*
An. freeborni	0.182	12.917	0.989	0.143	2.108	0.946	−8.314	8.373	0.329
Cs. incidens	34.238	11.822	0.005*	8.968	3.152	0.006*	−0.336	9.536	0.972
Cs. inornata	2.829	11.388	0.804	−0.027	2.007	0.989	−18.527	15.271	0.235
Cx. quinquefasciatus	−20.712	10.901	0.060	3.219	2.619	0.224	−30.629	15.727	0.061
Cx. tarsalis	−25.425	11.206	0.025*	−0.965	2.487	0.699	−4.221	16.298	0.797
Dog density	−0.874	8.092	0.914	−13.899	4.077	0.001*	62.701	20.786	0.005*
Income	−10.128	16.388	0.538	9.784	5.789	0.097	−81.849	16.851	< 0.001*
Full model	\({R}^{2}\)= 0.505			\({R}^{2}\)= 0.720			\({R}^{2}\)= 0.874
Year and bioregion dummy variables only	\({R}^{2}\)= 0.409			\({R}^{2}\)= 0.499			\({R}^{2}\)= 0.598
Year dummy variable only	\({R}^{2}\)= 0.405			\({R}^{2}\)= 0.492			\({R}^{2}\)= 0.503
Bioregion dummy variable only	\({R}^{2}\)= 0.401			\({R}^{2}\)= 0.505			\({R}^{2}\)= 0.617

Coefficient estimates, standard errors, and p-values for each predictor included in models of dog heartworm cases. Scaled coefficient estimates shown here denote the change in dog heartworm cases from a one standard deviation change in the predictor. Coefficients are scaled so that effects of different predictors are directly comparable. Statistically significant (p < 0.05) coefficients are denoted with *. Adjusted \({R}^{2}\) values are shown for four different model specifications: the full model including all predictors, a model including only the year and bioregion dummy variables, and a model including just the year, or just the bioregion dummy variable. Aedes albopictus was not included as a predictor in the model for Central California as it was not found in either Central California bioregion in any year.

ISSN: 1756-3305