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 Aysén 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 fit 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 confirms that the Aysén 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 financial resources available, that intervention activities ― at the beginning of a control program ― should be focused on farms with high prevalence and identified disease clusters.

囊性包虫病（CE）是一种人畜共患寄生虫病，由细粒棘球蚴幼虫期引起。这种疾病在世界范围内都有分布，在智利被认为是一种重要的人畜共患病，特别是在以畜牧业为主的地区。我们的目的是描述 2015 年至 2016 年间智利艾森地区屠宰的牛羊中 CE 的空间分布和风险因素，为该高流行地区的疾病控制提供信息。对农场层面的 CE 进行聚类和热点分析（莫兰全局指数、局部空间自相关指标 (LISA) 和扫描统计泊松模型），并使用空间插值来显示 CE 风险较高的区域。混合效应逻辑回归模型适合评估动物原产地城市和年龄与屠宰时检测到的 CE 之间的关联，其中原产地农场作为随机效应包括在内。

总体而言，分析了 1532 个养牛场（1078 头地理编码）和 30,805 头牛的数据，农场和动物层面的 CE 患病率分别为 64% 和 39%。对于绵羊养殖场，分析了来自 381 个（296 个地理编码）农场和 58,223 只羊的数据，农场和动物层面的 CE 患病率分别为 71% 和 18%。在全球范围内，牛场和羊场的 CE 患病率并不集中。然而，我们发现14个牛场和23个羊场的患病率较高，且集中在当地。我们还在牛场和羊场分别检测到 6 个和 11 个集群。报告的 CE 风险因来源城市和动物年龄而异。

这项研究证实艾森地区是 CE 的高发地区。它证明了屠宰动物的可追溯性对于了解 CE 流行病学的有用性。结果表明，在这个可用财政资源有限的高流行地区，在控制计划开始时的干预活动应重点关注流行率高和已确定疾病群的农场。