Space-time clustering of rabies in equines in Brazil from 2006 to 2023.

Abstract

Rabies is a lethal zoonosis caused by the rabies virus (RABV), primarily transmitted by the common vampire bat (Desmodus rotundus). Brazil, home to the largest equine population in South America, faces ongoing challenges with equine rabies, which impacts both the economy and public health. This study aimed to identify spatial and temporal patterns of rabies in equines in Brazil between 2006 and 2023. Data from the Zoosanitary Information System (SIZ) of the Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA) were used. The incidence risk (IR) was calculated for each region and Federative Unit. To identify spatial and temporal clusters, a spatiotemporal scan analysis was conducted using the Poisson model in SaTScan™. Temporal trends were analyzed using a segmented log-linear regression model in Joinpoint Regression. During the study period, 2170 cases of rabies in equines were reported in Brazil. The Southeast region accounted for 41.66 % of cases, followed by the Central-West (24.47 %). The Federative Units with the highest incidence risk were Espírito Santo (124.68/100,000 equines), São Paulo (69.97/100,000), and Rio de Janeiro (69.03/100,000). The retrospective spatiotemporal analysis identified four major clusters, notably in São Paulo, Mato Grosso, Espírito Santo, Rio de Janeiro, and Amazonas. The prospective analysis revealed active clusters in São Paulo, Espírito Santo, and Amazonas. Temporal trend analysis indicated a decline in equine rabies incidence in Brazil (APC: -3.9 %; CI: -6.2 to -1.5). The findings of this study provide valuable insights for the implementation of more effective preventive measures, directing epidemiological surveillance toward high-risk regions.