The study investigates the outbreak of Oropouche virus (OROV) in border regions of western Amazon, a re-emerging arbovirus causing acute fever. The research team identified 27 positive cases of OROV in individuals with acute febrile conditions, with 44.44% of the cohort showing reported symptoms such as fever, myalgia, and back pain. Molecular analysis of the S and M segments of the virus revealed similarities among Brazilian sequences, indicating the circulation of OROV in Rondonia and border areas. The study highlights the importance of genomic surveillance and the need for specific diagnostics to address the underreporting of OROV, which is influenced by seasonal periods and environmental factors. The findings underscore the public health concern and the necessity for continued monitoring and research in these regions.The study investigates the outbreak of Oropouche virus (OROV) in border regions of western Amazon, a re-emerging arbovirus causing acute fever. The research team identified 27 positive cases of OROV in individuals with acute febrile conditions, with 44.44% of the cohort showing reported symptoms such as fever, myalgia, and back pain. Molecular analysis of the S and M segments of the virus revealed similarities among Brazilian sequences, indicating the circulation of OROV in Rondonia and border areas. The study highlights the importance of genomic surveillance and the need for specific diagnostics to address the underreporting of OROV, which is influenced by seasonal periods and environmental factors. The findings underscore the public health concern and the necessity for continued monitoring and research in these regions.