Cases of the “sloth fever” have been reported in the United States, prompting a health advisory from the Centers for Disease Control and Prevention (CDC). The disease, known as the Oropouche Virus, primarily spreads through bites from midges, although certain mosquitoes can also transmit this potentially deadly illness.
On August 16, the CDC issued a Health Alert Network Advisory due to increased Oropouche Virus activity and the risk posed to travelers. The CDC notes that travel-related cases have been linked to individuals returning from Cuba and Brazil.
This year alone, over 8,000 Oropouche virus cases have been reported across Brazil, Bolivia, Peru, Colombia, and Cuba, resulting in two fatalities. Additionally, there have been five instances of transmission related to fetal death or congenital abnormalities.
Key information about the disease includes:
The Oropouche virus was first identified in 1955 in Trinidad and Tobago and is endemic to the Amazon basin. Outbreaks have previously been documented in several countries, including Bolivia, Brazil, Colombia, Ecuador, French Guiana, Panama, and Peru.
Human infections often occur in forested regions, where individuals can introduce the virus into urban settings.
While there have been travel-related Oropouche virus cases in the U.S., there is currently no evidence of local transmission within the country or its territories.
The incubation period for the illness can last up to ten days, with symptoms resembling those of other viral infections such as dengue, Zika, and chikungunya. Common symptoms include acute fever, chills, headache, muscle pain, and joint pain. Other symptoms may consist of eye pain, sensitivity to light, nausea, vomiting, diarrhea, fatigue, rash, and abdominal pain.
Serious complications can arise in a small percentage of cases—fewer than 5%—including meningitis, encephalitis, or bleeding, though fatalities from Oropouche virus are rare.