Informing Viral Surveillance of Oropouche Virus: an emerging arbovirus

Arboviruses are viruses transmitted by hematophagous arthropod vectors. Many of these viruses pose a threat to human health. While some infections may be asymptomatic, others may produce febrile illness, or manifest in life threatening conditions. Symptomatic diagnosis of patients with generalized febrile illness can be confounded due to the various diseases that present clinically in the same manner, and a lack of available diagnostic tests. Surveillance efforts can be used to create awareness about the prevalence of neglected tropical arthropod-borne pathogens, such as Oropouche virus (OROV), and inform preparedness measures for disease outbreaks (SURVEILLANCE SENTENCE). OROV is an arbovirus and the etiologic agent of human and animal disease. The primary vector of OROV is thought to be the biting midge, Culicoides paraenesis, though Culex quinquefasciatus, Cq. venezuelensis, and Aedes serratus mosquitoes are considered secondary vectors. There are no vaccines, diagnostics, or robust surveillance systems in place for OROV despite OROV being found in human patients in numerous countries that share border with Colombia: Ecuador, Peru, Brazil. In this study, synthesis of known data through review of published literature regarding OROV and vectors was done to determine if ecological variables could be associated with OROV prevalence and thus inform targeted surveillance efforts in resource strapped environments. Some common features were observed more frequently than others, though no one characteristic was statistically significantly associated with the presence of OROV using logistic classification models. Although there have not been any documented cases of OROV in Colombia, the presence of C. paraensis, the primary vector of OROV has been documented. However, when nearly 700 febrile patients were screened for OROV, none were positive by RT-qPCR. This indicates that while Colombia is presumably ecologically suitable for OROV circulation (given the presence of the vector), OROV has not emerged in that region. Altogether, this research has identified a significant gap in our understanding of OROV circulation, the eco-environmental drivers of transmission, and its emergence potential and indicates that more research is needed to identify those variables that may serve as ecological markers for transmission and emergence