Oropouche Fever: A Review

Abstract

Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV), an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and sylvatic transmission cycles, with the primary vector in the urban cycle being the anthropophilic biting midge Culicoides paraensis. Currently, there is no evidence of direct human-to-human OROV transmission. OROV fever is usually either undiagnosed due to its mild, self-limited manifestations or misdiagnosed because its clinical characteristics are similar to dengue, chikungunya, Zika and yellow fever, including malaria as well. At present, there is no specific antiviral treatment, and in the absence of a vaccine for effective prophylaxis of human populations in endemic areas, the disease prevention relies solely on vector control strategies and personal protection measures. OROV fever is considered to have the potential to spread across the American continent and under favorable climatic conditions may expand its geographic distribution to other continents. In view of OROV’s emergence, increased interest for formerly neglected tropical diseases and within the One Health concept, the existing knowledge and gaps of knowledge on OROV fever are reviewed.

Oropouche Virus Detection in Febrile Patients’ Saliva and Urine Samples in Salvador, Bahia, Brazil

“…The sequences were submitted to GenBank (Accession numbers: MF155931, MK875765-68, respectively). This is the first report of OROV infection in the Metropolitan Region of Bahia State, although it has been reported in nearby regions (2). Since Bahia State is geographically distant from the official OROV-endemic areas, the virus has probably been spread across the country via intense human transit.…”

Oropouche virus cases identified in Ecuador using an optimised rRT-PCR informed by metagenomic sequencing

“…OROV is one of the most clinically important orthobunyaviruses in the Americas, with over half a million cases and more than 30 major outbreaks reported since it was first isolated in Trinidad and Tobago in 1955 (4). These figures are likely to be underestimates, caused in part by underreporting due to the similar clinical presentation of other arboviral diseases that co-circulate in the same areas, including dengue virus (DENV), chikungunya virus (CHIKV), Mayaro virus (MAYV), yellow fever virus (YFV) and Zika virus (ZIKV) (4,5). Cases of Oropouche fever have been reported in Brazil, Peru, Panama, and Trinidad and Tobago (5).…”

“…These figures are likely to be underestimates, caused in part by underreporting due to the similar clinical presentation of other arboviral diseases that co-circulate in the same areas, including dengue virus (DENV), chikungunya virus (CHIKV), Mayaro virus (MAYV), yellow fever virus (YFV) and Zika virus (ZIKV) (4,5). Cases of Oropouche fever have been reported in Brazil, Peru, Panama, and Trinidad and Tobago (5). We recently isolated OROV for the first time from a patient in north-western Ecuador (6), suggesting that OROV may be circulating undetected in this region.…”

Upstream translation initiation expands the coding capacity of segmented negative-strand RNA viruses

“…To determine whether upstream translation initiation could occur in sNSVs, we examined three viruses: the orthomyxovirus influenza A virus (IAV), a cause of influenza in humans and other animals and the cause of all influenza pandemics [28], and two bunyaviruses: the tick-borne phenuivirus Heartland virus [29] and the midge-borne peribunyavirus Oropouche virus [30]. We demonstrated that, consistent with our hypothesis, each of these viruses is capable of upstream translation initiation.…”