Maladie à virus Oropouche

Oropouche virus disease is an emerging zoonotic condition caused by Oropouche virus, a segmented single-stranded RNA arbovirus of the genus Orthobunyavirus and family Peribunyaviridae ^[1][2][3]. The virus is endemic to parts of South America, Central America, and the Caribbean and is transmitted to humans through infected arthropod bites ^[2][3].

Symptomatic infection typically begins after a 3–10 day incubation period with abrupt fever, headache, joint and muscle pain, chills, nausea, vomiting, and rash, resembling other arboviral illnesses ^[2][3]. About 60% of infections are symptomatic, most patients recover within roughly a week although some experience prolonged illness or a biphasic recurrence of symptoms ^[2][3]. Severe manifestations including aseptic meningitis, encephalitis, Guillain-Barré syndrome, and, in 2024, deaths in previously healthy young adults have been documented ^[2][3].

Since its identification in 1955, Oropouche virus has caused over 30 epidemics and more than 500,000 clinical cases across Brazil, Peru, Panama, and Trinidad and Tobago, ranking as the second most common arboviral disease in South America before chikungunya and Zika emergence ^[1][2][5]. Prior to late 2023, cases clustered near the Amazon rainforest and Caribbean, but from December 2023 onward, locally transmitted cases appeared in new areas including seven Latin American and Caribbean countries, with 9,852 confirmed cases by late August 2024 and travel-imported cases in the United States and Europe ^[2][3][4]. The 2024 outbreak marked a turning point with sustained transmission in non-endemic Brazilian regions, Cuban local transmission, two fatal cases, and several vertical transmissions ^[4].

The virus is maintained in a sylvatic cycle among forest sloths, non-human primates, birds, and mosquitoes, and spreads in urban cycles via anthropophilic biting midges (Culicoides paraensis) and possibly mosquitoes ^[1][2][3]. Human infection occurs through the bite of infected insects, with no evidence of direct human-to-human spread, though vertical transmission during pregnancy has been reported ^[1][2][3].

With no licensed vaccine or specific antiviral available, prevention depends entirely on vector control and personal protection against biting midges and mosquitoes ^[1]. Reducing exposure through avoidance of arthropod bites in endemic and outbreak settings remains the sole public-health measure for population prophylaxis ^[1].

1. 1 Sakkas H et al. Oropouche Fever: A Review. Viruses. 2018 Apr 4. PMID: 29617280. doi: 10.3390/v10040175. PubMed: https://pubmed.ncbi.nlm.nih.gov/29617280/
2. 2 World Health Organization. Oropouche virus disease [Internet]. cited 4 Sept 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/oropouche-virus-disease
3. 3 Pastula DM et al. Oropouche Virus: An Emerging Neuroinvasive Arbovirus. Ann Neurol. 2024 Nov 19. PMID: 39560215. doi: 10.1002/ana.27139. PubMed: https://pubmed.ncbi.nlm.nih.gov/39560215/
4. 4 Tilston-Lunel NL et al. Oropouche Virus: An Emerging Orthobunyavirus. J Gen Virol. 2024 Oct. PMID: 39351896. doi: 10.1099/jgv.0.002027. PubMed: https://pubmed.ncbi.nlm.nih.gov/39351896/
5. 5 Travassos da Rosa JF et al. Oropouche Virus: Clinical, Epidemiological, and Molecular Aspects of a Neglected Orthobunyavirus. Am J Trop Med Hyg. 2017 May. PMID: 28167595. doi: 10.4269/ajtmh.16-0672. PubMed: https://pubmed.ncbi.nlm.nih.gov/28167595/