Oropouche Virus RNA Qualitative Real-Time RT-PCR

The Oropouche virus (OROV) is an arbovirus which is transmitted by the bite of infected midges and mosquitoes. OROV is an RNA virus that can cause fever, headache, joint pain, muscle pain, chills, nausea, vomiting, and rash. Most people recover on their own, but the disease can cause severe symptoms in some patients.

OROV is endemic in South America and a frequent arbovirus infection in Brazil. In the United States and Europe, travel-associated cases have been identified in travelers returning from Cuba and Brazil.

As testing and surveillance for OROV disease increases in the Americas, reports of cases from additional countries are expected. Currently no vaccine is available, and treatment is supportive care, as no specific antiviral agents exist.^1-3  

Testing should be performed on persons with an acute illness and epidemiological risk factors consistent with OROV infection. Due to the overlap in clinical presentations and vector distribution, additional testing targeting Dengue, Chikungunya, and Zika could be considered. The CDC recommends testing when it will help with clinical management and to prevent transmission. More information can be found at the following CDC website: Updated Interim Guidance for Health Departments on Testing and Reporting for Oropouche Virus Disease | Oropouche | CDC.¹

Diagnostic testing is based on nucleic acid amplification testing (NAAT) and serology (antibody testing). Currently, no US FDA-approved tests for OROV diagnostic testing are available. During the acute phase of infection (the first week of infection), viral detection is possible by culture or NAAT. NAAT is preferred over viral culture as it typically offers a faster time to results and higher clinical sensitivity. NAAT can detect viral RNA generally during the first 7 days of illness.⁴

IgM antibodies develop towards the end of the first week of illness, followed by IgG antibodies. Therefore, when a patient presents >7 days after symptom onset, serology tests are recommended. When possible, acute and convalescent serum should be tested to document a 4-fold or higher change in antibody titers to confirm recent infection.^3,4

Patients with neuroinvasive disease may have viral RNA detected in the CSF, but NAAT is often negative in these cases. Serological testing of CSF is preferred to diagnose neuroinvasive cases.

Quest offers a nucleic acid amplification (NAAT) laboratory-developed test: Oropouche Virus RNA Qualitative Real-Time RT-PCR (Test Code 14328)

This test cannot distinguish among closely related reassortants within the Orthobunyavirus genus, including the Madre de Dios virus, Iquitos virus, and Perdoes virus.

For details, visit the following CDC website: Updated Interim Guidance for Health Departments on Testing and Reporting for Oropouche Virus Disease | Oropouche | CDC.¹

Instructions: Each Oropouche specimen should be accompanied by its own separate requisition and transport container and sealed bag.

Preferred specimen types:

• 1.5 mL (0.5 mL minimum) serum in a red-top tube (no gel)

OR

• 1.5 mL (0.5 mL minimum) CSF in a plastic, sterile, leak-proof container

Specimens should be transported refrigerated (cold packs) or frozen.  

Most cases of Oropouche virus infectious are associated with febrile symptoms indistinguishable from other arboviral pathogens endemic to the Americas. During the acute phase of the disease, within the first 7 days of symptoms onset, nucleic acid amplification (NAAT) methods offer a rapid alternative over culture for the diagnosis of this disease. Serological testing should be considered 7 days after symptoms onset.