Distribuição das infeções por Oropouche em animais domésticos ao longo da BR-319, na região amazônica

Abstract

The Oropouche virus (OROV) is an emerging zoonotic arbovirus belonging to the Peribunyaviridae family, genus Orthobunyavirus, primarily transmitted by Culicoides paraensis. In Brazil, it is endemic in the Amazon region, causing outbreaks in humans and potentially in animals, and represents an important cause of febrile illness in areas undergoing urban expansion and increased interaction with sylvatic environments. This study aimed to determine the prevalence of OROV in humans and domestic animals along the BR-319 highway, identify associated risk factors, and evaluate the role of human–animal interaction in viral exposure. A cross-sectional study was conducted including 71 domestic animals (dogs, cats, pigs, cattle, sheep, and chickens) and their respective owners. Antibody detection was performed using enzyme-linked immunosorbent assay (ELISA) with N and Gc antigens and confirmed by plaque reduction neutralization test (PRNT₅₀). Viral RNA detection was assessed by RT-qPCR. The overall seroprevalence by PRNT₅₀ was 19.4%, with higher frequency in dogs (20.8%), while cattle and sheep were negative. In ELISA, the N antigen showed higher sensitivity (53.5%) compared to Gc (46.5%). No viral RNA was detected in the analyzed samples. In animals, seropositivity was associated with ectoparasite control practices, whereas in humans it was associated with the absence of treated piped water and inadequate solid waste management. Spatial analysis revealed higher seroprevalence in specific sections of the BR-319, suggesting transmission hotspots. The simultaneous detection of exposure in human–animal pairs (36.4%) indicates shared environmental risk. These findings demonstrate active and possibly continuous circulation of OROV along the BR-319, strongly influenced by environmental and socioecological factors. Domestic animals, particularly dogs, emerge as strategic epidemiological sentinels. These results highlight the importance of integrated One Health approaches for the surveillance and control of OROV in areas under environmental pressure.