What is Oropouche virus?

Oropouche virus (OROV) is a single-stranded RNA virus that belongs to the Peribunyaviridae family.¹ It is considered a public health threat in tropical and subtropical areas of the Americas, as it primarily circulates in Central and South America and the Caribbean.^1-3 

Oropouche virus causes a dengue-like illness called Oropouche fever. Outbreaks have been reported in both rural and urban areas of Brazil, Ecuador, Panama, Peru, Trinidad and Tobago, and French Guiana.^1-3 

How does it spread?

Oropouche virus is transmitted to humans through the bite of the Culicoides paraensis midge (a small fly), though mosquitoes also play a role in transmitting it between animals. To date, there has been no documented human-to-human transmission.^1-4

What are the symptoms?

Oropouche fever typically festers inside the body for 4-8 days before causing a sudden, dengue-like illness lasting 3-6 days. While most people recover quickly, up to 70% experience a milder recurrence of symptoms like fever and chills within two to three weeks. In some cases, patients experience a lingering weakness can last for several weeks after the initial illness.^2-4 The illness has a wide range of symptoms and potential complications:

Common symptoms:

• Chills
• Fatigue
• Nausea
• Vomiting
• Dizziness
• Joint pain
• Headache
• Muscle pain
• Sudden onset of high fever

Rare symptoms: 

• Nosebleeds
• Bleeding gums
• Light sensitivity
• Spontaneous bleeding
• Pinpoint bleeding under the skin (petechiae)
• Skin rash (more common on the trunk and arms), 
• Central nervous system issues like meningitis or encephalitis (inflammation of the membranes around the brain and spinal cord)

How do I get a diagnosis?

Diagnosing Oropouche virus is challenging, because it is so similar to other viral infections, and there is a  lack of widely available specific tests. Diagnosis requires specialized lab tests that go beyond routine bloodwork. Serologic tests are commonly used to detect antibodies (proteins produced by the immune system to fight the virus), while molecular tests like RT-PCR detect and quantify the amount of viral RNA present.⁵ The choice of test may depend on factors like the stage of the illness, available resources, and the need for rapid diagnosis.

Is there a treatment?

There is no specific treatment for Oropouche fever other than focusing on managing symptoms. The prognosis is generally good, with most patients recovering fully.⁵ But, the potential for severe complications like aseptic meningitis highlights how important it is to receive timely diagnosis and supportive care.

Preventative efforts focus on reducing midge breeding sites and minimizing contact between midges and people. You can protect yourself by using insect repellent, wearing protective clothing, and using bed nets.⁵

Where can I find more information? 

For more information, you can check out resources from the CDC and WHO.

References

1. Oropouche virus disease – French Guiana, France (no date) World Health Organization. Available at: https://www.who.int/emergencies/disease-outbreak-news/item/oropouche-virus-disease—french-guiana-france (Accessed: 10 June 2024). 
2. Moutinho, S. (2024) A little-known virus on the rise in South America could overwhelm health systems. Available at: https://www.science.org/content/article/little-known-virus-rise-south-america-could-overwhelm-health-systems (Accessed: 10 June 2024). 
3. Oropouche fever in the Americas – level 1 – level 1 – practice usual precautions – travel health notices (no date) Centers for Disease Control and Prevention. Available at: https://wwwnc.cdc.gov/travel/notices/level1/oropouche-fever-brazil (Accessed: 10 June 2024). 
4. Romero-Alvarez, D. and Escobar, L.E. (2018) ‘Oropouche fever, an emergent disease from the Americas’, Microbes and Infection, 20(3), pp. 135–146. doi:10.1016/j.micinf.2017.11.013. 
5. Sakkas, H. et al. (2018) ‘Oropouche fever: A Review’, Viruses, 10(4), p. 175. doi:10.3390/v10040175.