CDC Issues Oropouche Virus Alert for US Travelers and Doctors

The Centers for Disease Control and Prevention headquarters in Atlanta on April 23, 2020. (Tami Chappell/AFP via Getty Images

The U.S. Centers for Disease Control and Prevention sent a health alert and a separate travel alert to Cuba because of an increase in Oropouche virus disease in the Americas region, saying the disease has caused two deaths so far this year.

Oropouche virus spreads through the bites of infected midges, which are small flies, and possibly certain mosquitoes, officials say.

So far in 2024, more than 8,000 cases of the virus have been reported in Brazil, Bolivia, Peru, Colombia, and Cuba, with two deaths and five cases associated with fetal death or “congenital abnormalities,” the CDC said. Several travel-associated cases of the virus have been reported in the United States and Europe as well, the agency said.

“As testing and surveillance for Oropouche virus disease increase in the Americas, reports of cases from additional countries are expected,” stated the Aug. 16 health advisory, which was sent to doctors and health authorities.

Although more cases are expected due to increased testing and surveillance, there has been no local transmission in the United States, the CDC said.

Clinicians and health officials should consider the virus among people who traveled to areas with suspected or confirmed cases within two weeks of their initial symptoms. Clinicians are also asked to be cognizant of the risk of “vertical transmission” of the virus in pregnant women who are confirmed to have an Oropouche infection.

Separately, the CDC issued a Level 2 travel notice about the Oropouche virus for individuals traveling to Cuba. Pregnant women are being asked to “reconsider non-essential travel” to the country, the agency said.

“If travel is unavoidable, these travelers should strictly follow Oropouche prevention recommendations,” the CDC said.

There are no vaccines or specific treatments for the virus, which some media outlets have called “sloth fever” because it can be transmitted among sloths as well as primates and marsupials.

About 60 percent of people infected with the virus display symptoms, the CDC alert said. They include severe headache, fever, muscle and joint pain, dizziness, nausea, light sensitivity, and chills between three and 10 days after an infection.

Most people recover within several days to a month, the agency said. The symptoms last less than a week, but they often recur days or sometimes weeks later, it added.

A small percentage of people infected with the Oropouche virus, named after the river on which it was discovered in Trinidad and Tobago, can develop meningitis, brain inflammation, and internal bleeding, according to the agency.

It was first discovered in 1955 and has been circulating in the Caribbean and Latin America since then, researchers say.  There have been a handful of outbreaks in Peru and Brazil.

Stephen Graham, a professor with the University of Cambridge’s school of infectious diseases, noted that the outbreak of the virus is unusual due to its broad geographic transmission across South and Central America

“This latest outbreak is notable because the virus has spread much further geographically than it has in previous outbreaks, as far north as Cuba and as far south as Sao Paulo state. There have also been cases imported by travelers into Spain, Italy, and Florida,” Graham said in a statement issued by the school.

The virus, he added, has an RNA genome like the virus that causes COVID-19, meaning it is “capable of rapid mutation.”

“It also has a genome with multiple segments, like influenza. This means that if you are unlucky enough to be infected with two different strains of the virus they can ‘reassort’ their genome segments, like shuffling two decks of cards together, and you might end up with a new virus strain that is more transmissible and/or more pathogenic,” he said, adding that the new outbreak may be caused by this phenomenon.