
A potentially deadly virus often known as “sloth fever” has US officials on alert after Florida reported 20 travel-related cases, including nine last week.
Oropouche virus is spread through the bites of infected small flies and mosquitoes. It’s common in parts of South America, though Florida noted that its 20 cases — the primary within the US — stemmed from Cuba travel. The virus has also been detected in Europe.
Infection could cause a headache, joint stiffness, pain, nausea and even death in a few rare cases. It’s particularly problematic for pregnant women.
Here’s all the things you want to learn about this emerging threat.
What’s ‘sloth fever’?
Oropouche virus (pronounced o-ro-push) is transmitted via midge and mosquito bites to animals and humans, making it an arbovirus. The disease is thought colloquially as “sloth fever,” as those slow-moving, bone-breaking mammals are among the many animals often infected.
The primary virus case was recorded in 1955 in a village near the Oropouche River within the Amazon River Basin. During outbreaks, humans carrying the virus are fed upon by insects, who then infect other people.
In keeping with the Lancet Infectious Diseases journal, there have been around 500,000 recorded cases for the reason that disease was first identified. The virus has circulated in Latin America and the Caribbean, with sporadic outbreaks in Brazil and Peru.
From January to the beginning of August, greater than 8,000 “sloth fever” cases have been reported. There have been 832 recorded in 2023.
Of those 8,000 cases, two deaths were recorded in Brazil in July. A couple of instances of transmission from mother to fetus have also occurred, leading to fetal death or birth defects.
What are ‘sloth fever’ symptoms?
The incubation period for sloth fever is three to 10 days. Symptoms often begin with a sudden fever and a severe headache, much like those related to dengue, chikungunya, Zika viruses or malaria.
Symptoms often last lower than every week, but some patients experience weakness for up to 1 month.
Around 60% of those infected develop symptoms, which include:
- Headache
- Chills
- Nausea
- Fever
- Maculopapular rash
- Muscle soreness
- Eye pain
- Joint pain
- Vomiting
- Diarrhea
- Fatigue
- Abdominal pain
Severe symptoms
In as much as 4% of patients, infection could cause neuroinvasive diseases like meningitis and encephalitis.
Symptoms of neuroinvasive complications include eye pain, confusion, weakness, light sensitivity, neck stiffness and involuntary eye movement.
Sloth fever prevention
One of the best defense is bite prevention via insect repellent and window and door screens.
There are not any vaccines to stop Oropouche infection. The CDC recommends that pregnant people reconsider nonessential travel to areas of infection, like Cuba.
How is sloth fever treated?
There are not any medications that specifically treat Oropouche virus.
Per the CDC, rest, fluids and over-the-counter pain relievers can address symptoms. To scale back the chance of hemorrhage, aspirin and other nonsteroidal anti-inflammatory drugs ought to be avoided.
Patients who experience severe symptoms should seek immediate medical treatment.

A potentially deadly virus often known as “sloth fever” has US officials on alert after Florida reported 20 travel-related cases, including nine last week.
Oropouche virus is spread through the bites of infected small flies and mosquitoes. It’s common in parts of South America, though Florida noted that its 20 cases — the primary within the US — stemmed from Cuba travel. The virus has also been detected in Europe.
Infection could cause a headache, joint stiffness, pain, nausea and even death in a few rare cases. It’s particularly problematic for pregnant women.
Here’s all the things you want to learn about this emerging threat.
What’s ‘sloth fever’?
Oropouche virus (pronounced o-ro-push) is transmitted via midge and mosquito bites to animals and humans, making it an arbovirus. The disease is thought colloquially as “sloth fever,” as those slow-moving, bone-breaking mammals are among the many animals often infected.
The primary virus case was recorded in 1955 in a village near the Oropouche River within the Amazon River Basin. During outbreaks, humans carrying the virus are fed upon by insects, who then infect other people.
In keeping with the Lancet Infectious Diseases journal, there have been around 500,000 recorded cases for the reason that disease was first identified. The virus has circulated in Latin America and the Caribbean, with sporadic outbreaks in Brazil and Peru.
From January to the beginning of August, greater than 8,000 “sloth fever” cases have been reported. There have been 832 recorded in 2023.
Of those 8,000 cases, two deaths were recorded in Brazil in July. A couple of instances of transmission from mother to fetus have also occurred, leading to fetal death or birth defects.
What are ‘sloth fever’ symptoms?
The incubation period for sloth fever is three to 10 days. Symptoms often begin with a sudden fever and a severe headache, much like those related to dengue, chikungunya, Zika viruses or malaria.
Symptoms often last lower than every week, but some patients experience weakness for up to 1 month.
Around 60% of those infected develop symptoms, which include:
- Headache
- Chills
- Nausea
- Fever
- Maculopapular rash
- Muscle soreness
- Eye pain
- Joint pain
- Vomiting
- Diarrhea
- Fatigue
- Abdominal pain
Severe symptoms
In as much as 4% of patients, infection could cause neuroinvasive diseases like meningitis and encephalitis.
Symptoms of neuroinvasive complications include eye pain, confusion, weakness, light sensitivity, neck stiffness and involuntary eye movement.
Sloth fever prevention
One of the best defense is bite prevention via insect repellent and window and door screens.
There are not any vaccines to stop Oropouche infection. The CDC recommends that pregnant people reconsider nonessential travel to areas of infection, like Cuba.
How is sloth fever treated?
There are not any medications that specifically treat Oropouche virus.
Per the CDC, rest, fluids and over-the-counter pain relievers can address symptoms. To scale back the chance of hemorrhage, aspirin and other nonsteroidal anti-inflammatory drugs ought to be avoided.
Patients who experience severe symptoms should seek immediate medical treatment.







