SUMMARY:

The Oropouche virus, transmitted via bites from infected mosquitoes or midges (a type of fly), has been primarily identified in the Amazon basin. In 2023, South America and Haiti had significant outbreaks, and it has been identified in Cuba. The CDC reports on cases in the United States, including whether travel -associated or locally acquired (see ‘Learn More – Primary Sources’). Although it is generally not a fatal disorder, with 2 deaths recorded among 8000 cases, there is a new association of adverse pregnancy outcomes such as stillbirth, miscarriage and congenital anomalies. A true causal relationship has not been proven. There are no current methods for preventing vertical transmission at this time. No antiviral therapy is available, and management is by supportive care. The following summarizes professional guidance on this topic.

BACKGROUND:

• Oropouche virus is a member of the Orthobunyavirus genus
• Symptoms
  •  Similar to Zika, Dengue, and Chikungunya viral infections
  • Typical symptoms: Myalgias | Athralgias | Fever | Chills | Headache | Maculopapular rash from the trunk to the extremities
  • Severe symptoms: Meningitis | Meningoencephalitis
  • Symptoms range from 2 to 7 days but may recur in 70% of individuals within days or weeks
  • No difference in symptoms between the pregnant and non pregnant population
• It is generally not fatal

Evidence of the Virus

• Virus can be detected in serum samples during the first week of infection
• Virus is readily cultured during the first few days of the infection | Not typically detected beyond day 5
• Viral RNA can be detected for several more days after the virus is no longer present
• Antibodies
  • IgM detectable toward the end of the first week of illness followed by IgG

Pregnancy

• An association with adverse pregnancy outcome and congenital anomalies has been made
  • Microcephaly | Cystic brain lesions | Fetal demise has been noted
• It is unknown whether Oropouche virus directly causes poor maternal or fetal outcomes

Testing

• Testing is advised for symptomatic patients
  • Testing for both dengue and Oropouche is advised due to their similar clinical presentations
  • Proper clinical management of dengue can lead to better patient outcomes
• CDC can perform real-time reverse transcription-polymerase chain reaction (RT-PCR) to detect viral RNA in serum and CSF during the acute phase of the illness
• CDC also can perform plaque reduction neutralization tests (PRNTs) to detect virus-specific neutralizing antibodies in serum and CSF
• To confirm a recent infection using serologic testing, both acute and convalescent samples are needed to document a 4-fold or greater change in antibody titer
• To obtain testing, contact local or state health department

Treatment

• No specific medical therapy is available
• Treatment is supportive care: Rest | Analgesics | Antipyretics | Fluids
• If symptomatic after traveling to an endemic area, test for Dengue and Oropouche virus
  • Contact state or local health department to arrange

KEY POINTS:

• Pregnant women considering travel to endemic areas should be counseled regarding maternal and fetal risks
  • Encourage EPA approved insect repellent and long sleeves outdoors
  • Review CDC resources for geographic exposures and resultant risk
• Fetal diagnostic testing is not available
• Serial sonograms (every 4 weeks) with emphasis on evaluating neuroanatomy should be performed if the disease is confirmed
• It is unknown if this virus can be transmitted via breastfeeding
  • Breastfeeding remains recommended

Learn More – Primary Sources:

ACOG Practice Advisory: Update on Oropouche Virus and Potential Effects on Pregnancy | ACOG

CDC: Oropouche Current Year Data

CDC: Clinical Overview of Oropouche Virus Disease

CDC: Caring for Patients with Oropouche Virus Disease

Oropouche Fever – Society for Maternal-Fetal Medicine

Oropouche fever, the mysterious threat

Locate a Specialist:

Locate a Maternal Fetal Medicine Specialist: SMFM

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