The pediatrician’s first patient of the day was a 15-year-old boy complaining of fever, chills, and profound arthralgias. His exam, including a careful assessment of his joints, yielded no clues, and the pediatrician was ready to diagnose this as a routine viral illness. An additional bit of history provided by the patient’s mother prompted the pediatrician to pause and reconsider.
“A week ago, we returned from a visit to Cuba,” the mother reported. “Could this be Oropouche virus infection?”
Dr. Kristina K. Bryant
Oropouche virus disease is an arboviral disease caused by the Oropouche virus (OROV). It is transmitted to humans through midge or mosquito bites. Although largely unknown to most United States clinicians until recently, this vector-borne virus is not new. The first human Oropouche virus infection was identified in Trinidad and Tobago in 1955 and since then, there have been intermittent outbreaks in the Amazon region. In recent months, though, the epidemiology of Oropouche virus infections has changed. Infections are being identified in new geographic areas, including Cuba. According to the Pan American Health Organization, 506 cases of Oropouche virus infection have been identified in Cuba since May 27, 2024.
Two deaths from Oropouche virus infection have been reported in previously healthy people. Evolving data suggests adverse outcomes associated with vertical transmission during pregnancy. One fetal death and child with congenital anomalies have been reported in Brazil. Additional fetal deaths, miscarriages, and congenital anomalies are under investigation.
Travel-associated cases have been reported in the United States. As of September 10, 2024, 52 Oropouche virus disease cases had been reported from five states in the United States. The Centers for Disease Control and Prevention confirmed that the first 31 of these cases were travelers returning from Cuba. The CDC issued a health advisory on August 16, 2024: Increased Oropouche Virus Activity and Associated Risk to Travelers.
The pediatrician quickly reviewed the signs and symptoms of Oropouche virus infection. Disease typically presents as an abrupt onset of fever, severe headache, chills, myalgia, and arthralgia 3 to 10 days after the bite of infected mosquito. Some patients develop a maculopapular rash that starts on the trunk and spreads to the extremities. Meningitis and encephalitis develop in less than 1 in 20 people. The symptoms of Oropouche virus infection overlap with those of other arboviruses such as dengue, chikungunya, and Zika viruses. The disease can also mimic malaria or rickettsial infection. Approximately 60% of people with Oropouche virus infection experience a recurrence of symptoms within days to weeks of the initial resolution of symptoms.
Testing for Oropouche virus infection is available through the CDC’s Arbovirus Diagnostic Laboratory. In people who are acutely ill, reverse transcription-polymerase chain reaction testing can be used to identify the virus in serum and cerebrospinal fluid. Serologic testing is also available for people who have been symptomatic for at least 6 days.
The pediatrician contacted his local health department to discuss the possibility of Oropouche virus infection. After reviewing the case definition, public health authorities recommended laboratory testing for Oropouche virus, dengue, and Zika virus.
Back in the exam room, the pediatrician provided anticipatory guidance to the patient and his mother. There are no antiviral medications to treat Oropouche virus infection, so the pediatrician recommended supportive care, including acetaminophen for fever and pain. He also advised avoiding aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) until dengue could be ruled out to reduce the risk of bleeding. After confirming that no one else in the home was sick with similar symptoms, he counseled about prevention strategies.
To date, transmission of Oropouche virus in the United States has not been documented, but vectors potentially capable of transmitting the virus are present in some areas of the United States. When people who are infected with Oropouche are bitten, they can spread the virus through their blood to biting midges or mosquitoes. The insects can then spread the virus to other people. To reduce to potential for local transmission, people who are sick with suspected Oropouche virus infection are advised to avoid biting-midge and mosquito bites for the first week of their illness. Any person who has recently traveled to an area where Oropouche virus transmission is occurring should also avoid insect bites for 3 weeks after returning home to account for the potential incubation period of the virus. This includes wearing an EPA-registered insect repellent.