Spatial analysis of Fasciola hepatica prevalence in sheep flocks from Córdoba, Argentina using GWR and IDW models.

Abstract

Fasciola hepatica is a zoonotic trematode with a widespread global distribution, impacting both livestock and humans. Despite its acknowledged effect on animal production, there is a lack of published data regarding its prevalence in sheep from the Córdoba province, Argentina. This study aimed to evaluate the prevalence of F. hepatica in flocks across six departments in northwestern Córdoba and to investigate the spatial and environmental factors associated with infection. A total of 894 fecal samples from 27 sheep flocks were analyzed using sedimentation techniques. The overall prevalence was found to be 46 %, with the highest values observed in the Cruz del Eje and Pocho departments (74 %). Spatial analysis utilizing Inverse Distance Weighted (IDW) interpolation revealed a heterogeneous distribution, with a higher prevalence concentrated in the northern region. Geographically Weighted Regression (GWR) indicated that altitude was positively associated with prevalence, whereas a greater distance to water sources was negatively associated. These spatial patterns varied by subarea, underscoring the significance of local environmental conditions. Furthermore, 50 % of the farmers employed ineffective antiparasitic drugs, and only 5 % were aware of the zoonotic potential of the disease. This study constitutes the first spatially explicit report of ovine fasciolosis in Córdoba and underscores the necessity for targeted control strategies that consider local risk factors.