Temporal changes in rabies epidemiology in Brazil: an analysis of notifications of suspected and confirmed human rabies cases, 2010–2025

Abstract

Human rabies is an invariably fatal encephalitis caused by Lyssavirus species, with near- 100% lethality after symptom onset. In Brazil, canine vaccination has markedly reduced urban transmission. However, human deaths continue to occur and are increasingly linked to sylvatic reservoirs, particularly Desmodus rotundus bats. This study describes the epidemiological profile of human rabies in Brazil from 2010 to 2025, focusing on temporal trends, aggressor species, demographics, geographic distribution, and genetic/antigenic variants. This descriptive time-series study used secondary data from the Notifiable Diseases Information System (SINAN/DATASUS): 1,482 notifications from 16 database files. Antigenic variant data were obtained from the Ministry of Health, and spatial distribution was analyzed using QGIS. Of these, 46 (3.1%) were confirmed, and 41 had recorded dates of death in SINAN. Peaks in the notifications of suspected rabies cases occurred in 2017 (n = 228), whereas confirmed cases peaked in 2018 (n = 11), when all infections were attributed to bats, including a cluster of 10 cases in Para. Men accounted for 55.9% of the notifications, and those aged ≥ 60 and 30–39 years were the most affected. Dogs caused 65.6% of the aggressions, but bats predominated among confirmed cases from 2017 onward. Genetic/antigenic variant analysis identified three active sylvatic cycles: AgV3 (D. rotundus), marmoset lineage (Callithrix jacchus), and wild canid lineage (Cerdocyon thous). No confirmed human rabies cases associated with domestic canine lineages or variants have been reported since 2015. These findings show a shift from urban dog-mediated rabies to sylvatic rabies in Brazil.