Three cases of Oropouche virus, also known as 'sloth fever', have been confirmed in the United Kingdom, according to health officials. The virus, which is endemic to the Amazon region, has been spreading beyond its usual range since late 2023, causing over 8,000 cases in the Americas in the first seven months of 2024.
The UK cases were detected in travellers who had recently returned from Brazil and Cuba. The virus is transmitted by biting insects, primarily the midge species Culicoides paraensis, and can cause fever, headache, and muscle pain. While most cases are mild, the virus can cross the blood-brain barrier and has been linked to two deaths in Brazil and potential harm to unborn children.
Recent genetic analysis suggests the virus has undergone changes that may make it more potent, allowing it to replicate more efficiently in human cells. This has raised concerns among public health officials, as the virus is now appearing in areas outside the Amazon basin, including non-Amazonian states in Brazil and Cuba.
There is no specific treatment or vaccine for Oropouche virus. Health authorities advise travellers to affected regions to take precautions against insect bites, such as using insect repellent and wearing long sleeves.
