Oropouche Virus Infection: Molecular Insights, Vector Ecology, and Human Health Implications

Oropouche virus (OROV), an arthropod-borne virus (arbovirus) belonging to the genus Orthobunyavirus within the family Peribunyaviridae, is a significant and emerging public health concern in Central and South America. First isolated in Trinidad and Tobago in 1955, OROV has been responsible for numerous outbreaks, resulting in over half a million human infections. It is the causative agent of Oropouche fever, an acute, often biphasic febrile illness whose symptoms—including high fever, intense headache, myalgia, arthralgia, and rash—closely mimic those of dengue and chikungunya, complicating clinical diagnosis. While typically self-limiting, severe neurological manifestations such as meningitis and encephalitis have been documented. The primary transmission cycle involves biting midges of the genus Culicoides, particularly C. paraensis, with a sylvatic cycle maintained among wild vertebrates like sloths and non-human primates. A critical feature of OROV's epidemiology is its increasing urbanization, facilitated by environmental changes, human travel, and the adaptability of its vectors. The virus possesses a tri-segmented, negative-sense single-stranded RNA genome that contributes to its genetic diversity and potential for reassortment. Currently, no specific antiviral drugs or licensed vaccines are available, rendering disease management solely supportive. Prevention relies on vector control and personal protective measures. This comprehensive review synthesizes the current knowledge on OROV, detailing its history, classification, structure, replication cycle, pathogenesis, clinical manifestations, diagnosis, treatment, and prevention. It underscores the urgent need for enhanced surveillance, continued research, and the development of effective countermeasures to mitigate the growing threat posed by this neglected tropical pathogen.