Oropouche virus, often nicknamed ‘sloth virus,’ is a growing concern in the Americas. As of August 16, 2024, over 20 cases have been confirmed in travelers returning to the U.S. from Cuba, marking the first known instances of the disease within the country. This follows 19 cases detected in travelers returning to Europe from the Americas earlier this summer. While no deaths have been reported in the U.S., health officials are urging travelers to areas where the virus circulates, particularly pregnant women, to exercise caution. Here’s what we know about Oropouche virus:
What is Oropouche virus?
Oropouche virus disease is a mosquito-borne illness similar to Zika, dengue, chikungunya, and malaria. It was first identified in a forest worker in Trinidad and Tobago in 1955. The name ‘sloth virus’ emerged from research suggesting the pale-throated sloth as a potential primary host of the virus. However, other studies indicate that wild birds or primates like capuchin and howler monkeys might be the main carriers.
Symptoms of Oropouche virus
The symptoms of Oropouche virus typically appear four to eight days after infection and resemble those of other mosquito-borne illnesses. They include:
* Sudden fever
* Headache
* Joint stiffness and pain
* Chills
* Nausea and vomiting
While most cases are mild and resolve within a week, severe complications can occur in less than 5% of patients. These complications include:
* Meningitis (inflammation around the spinal cord and brain)
* Encephalitis (inflammation of the brain)
Two deaths from severe Oropouche virus disease have been recently reported in Brazil.
Transmission of the virus
The primary vector for Oropouche virus is a biting fly called a midge, specifically the species Culicoides paraensis. These midges are commonly found in forests and around bodies of water in the Americas. While not present in Europe, they are present in several states within the U.S. The virus can also be transmitted by some mosquito species, including Culex quinquefasciatus. Direct human-to-human transmission has not yet been reported.
Where have cases been reported?
Over the last six decades, over 30 epidemics of Oropouche virus disease have been reported in South and Central America and the Caribbean, affecting over half a million people. Outbreaks have recently been reported in Brazil, Bolivia, Colombia, Peru, and Cuba. Cuba reported its first-ever known cases in June 2024. Climate change is creating conditions favorable for the virus’s spread.
All reported cases in the U.S. to date involve travelers returning from Cuba, with 20 cases in Florida and one in New York. The majority of patients experienced a self-limiting illness that resolved without treatment. However, the CDC reports that at least three patients have experienced recurring symptoms after their initial recovery. Europe has also recorded 19 imported cases, with 18 from travelers returning from Cuba and one from Brazil.
Treatments and Prevention
Currently, no specific treatments or vaccines are available for Oropouche virus disease. The CDC recommends managing symptoms by:
* Staying hydrated
* Resting adequately
* Taking over-the-counter pain relievers like acetaminophen to reduce fever and pain.
Prevention measures are focused on avoiding insect bites while traveling to affected areas. This includes:
* Using EPA-registered insect repellents
* Wearing long-sleeved shirts and pants when outdoors
* Utilizing insecticide-treated bed nets in rooms without adequate air conditioning or screens
Pregnant travelers should discuss their travel plans with their healthcare provider and consider avoiding non-essential travel to high-risk areas, like Cuba.
Pregnancy Concerns
Health officials are investigating a potential link between Oropouche virus infection during pregnancy and adverse birth outcomes, such as miscarriage and stillbirth. The Brazilian Ministry of Health has reported six possible cases of mother-to-child transmission during pregnancy, associated with microcephaly and miscarriage. This is concerning due to the known link between Zika infection during pregnancy and microcephaly. However, further research is needed to confirm a causal relationship between Oropouche virus and microcephaly.
Stay Informed and Protect Yourself
The spread of Oropouche virus highlights the need for travelers to be informed and take precautions to protect themselves from mosquito-borne illnesses. Consult with healthcare providers for up-to-date information and advice before traveling to areas where the virus is present.
