Veterinary Parasitology 287 (2020) 109258 Available online 30 September 2020 0304-4017/© 2020 Elsevier B.V. All rights reserved. Spatial epidemiology of cystic echinococcosis in livestock from a hyper-endemic region in southern Chile Hamilton Hombo a, b, 1 , Miguel Oyarzo c , Claudia ´ Alvarez c , Natalia Cuadros a , Felipe Hern´ andez a , Michael P. Ward d , Gerardo Acosta-Jamett a, e, * a Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile b Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile c Unidad de Zoonosis, Secretaría Regional Ministerial de Salud, Regi´ on de Ays´ en, Coyhaique, Chile d Sydney School of Veterinary Science, The University of Sydney, 425 Werombi Road, Private Mailbag 4003, Narellan, NSW, 2567, Australia e Programa de investigaci´ on Aplicada en Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile A R T I C L E INFO Keywords: Echinococcus granulosus Spatial epidemiology Cystic echinococcosis Cattle Sheep Livestock ABSTRACT Cystic echinococcosis (CE) is a parasitic zoonosis, caused by the larval stage of Echinococcus granulosus. This disease has a worldwide distribution and is considered an important zoonosis in Chile, especially in regions where raising livestock dominates. We aimed to describe the spatial distribution and risk factors for CE in cattle and sheep slaughtered in the Ays´ en Region, Chile between 2015 and 2016, to inform disease control in this hyper-endemic region. Clustering and hotspot analyses of CE at the farm-level were performed (Moran’s global index, local indicator of spatial autocorrelation (LISA), and the scan statistic Poisson model), and we used spatial interpolation to display areas with a higher risk of CE. Mixed effects logistic regression models were ft to assess the association between municipality of origin and age of animals and CE detected at slaughter, with the farm of origin included as a random effect. Overall, data from 1532 cattle farms (1078 geocoded) and 30,805 cattle were analyzed, with a 64 % and 39 % CE prevalence at the farm and animal-level, respectively. For sheep farms, data from 381 (296 geocoded) farms and 58,223 sheep were analyzed, with a 71 % and 18 % CE prevalence at the farm and animal-level, respectively. Globally, the CE prevalence in both cattle and sheep farms was not clustered. However, we found 14 cattle and 23 sheep farms with high prevalence that were locally clustered. We also detected 6 and 11 clusters in cattle and sheep farms, respectively. Risk of reported CE varied according to municipalities of origin, and the age of animals. This study confrms that the Ays´ en region is a hyper-endemic region for CE. It demonstrates the usefulness of the traceability of animals slaughtered for understanding the epidemiology of CE. The results suggest that in this hyper-endemic region in which there are limited fnancial resources available, that intervention activities – at the beginning of a control program – should be focused on farms with high prevalence and identifed disease clusters. 1. Introduction Cystic echinococcosis (CE), also known as hydatidosis, is a parasitic zoonosis caused by the larval stage of Echinococcus granulosus sensu lato (s.l.). It negatively impacts public health and domestic livestock globally (Budke et al., 2006). The life cycle of this parasite involves domestic dogs and other canids as defnitive hosts, in addition to sheep and other ungulates (e.g. cattle, goats, pigs) that act as intermediate hosts (i.e. hydatid cysts mainly located in their liver or lungs; Moro and Schantz, 2006; Craig et al., 2007; Cardona and Carmena, 2013). Dogs typically acquire the parasite through the consumption of viscera infected with fertile cysts from livestock slaughtered for domestic consumption (McManus and Thompson, 2003; Larrieu et al., 2004; Larrieu and Zanini, 2012). Humans are infected when they accidentally ingest eggs, for example after petting dogs or consuming vegetables contaminated with feces (Eckert and Deplazes, 2004; Craig et al., 2007). * Corresponding author at: Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile. E-mail address: gerardo.acosta@uach.cl (G. Acosta-Jamett). 1 Current address: Faculdade de Medicina Veterin´ aria, Universidade Jos´ e Eduardo dos Santos, Huambo, Angola. Contents lists available at ScienceDirect Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar https://doi.org/10.1016/j.vetpar.2020.109258 Received 29 April 2020; Received in revised form 26 September 2020; Accepted 27 September 2020