TABLE III. Model selection of risk factors for Trypanosoma cruzi seropositive reactions in dogs at the household level in Trinidad de Las Minas, western Republic of Panama.

Selection round	Risk factors	AIC	ΔAIC
0a	Palms + VI + HP + DAI + WPI	37.10	11.37
	PI + VI + HP + DAI + WPI	35.72	9.99
	PI + VI + HP + DSR + WSR	33.28	7.55
	Palms + VI + DI + DSR + WSR	31.62	5.89
	Npalms + VI + HP + DAI + WPI	30.52	4.79
	Npalms + VI + DI + DSR + WSR	26.81	1.08
1b	Npalms + DSR	25.73	--

a: models with the same number of parameters, but alternative covariates; b: final model from the stepwise backward elimination of selection round 0; AIC: Akaike Information Criterion; DAI: domestic animal abundance index; DSR: domestic animal species richness; HP: housing destituness; Npalms: palms in the peridomicile of the focal household and/or any of its two closest neighbours; Palms: palms in the peridomicile; PI: peridomicile index; VI: vegetation index; WPI: wild animal presence index; WSR: wildlife animal species richness; ΔAIC: is the difference between each model AIC with that of the model with minimum AIC. The final best model (minimum AIC) is bolded.