A deadly malaria-like “sloth virus” has been detected in Britain for the first time, triggering a warning from the UK’s health watchdog to those with symptoms to seek urgent medical help.
UK Health Security Agency (UKHSA) data has revealed there were three cases of Oropouche virus reported in Britain between January and June this year.
The tropical disease is usually found in South America and can cause fevers, headaches, pain behind the eyes, and in rare instances lead to meningitis and death, the watchdog warned.
“If a person becomes unwell with symptoms such as high fever, chills, headache, joint pain and muscle aches following travel to affected areas, they should seek urgent medical advice,” the UKHSA warned.
All three cases were people who had returned to the UK after travelling abroad to Brazil after a surge of virus infections across the region.
The lesser-known infection is spread through bites from small midges and some mosquitos, and can also be transmitted through sexual activity.
It is also feared the disease can be spread from mothers to babies during pregnancy, which can cause congenital or developmental abnormalities, according to the watchdog.
Symptoms usually show up four to eight days after being bitten and can last up to a week, but in nearly two thirds of cases they can return days or weeks later.
The onset of the illness is sudden and can include joint pain, muscle aches, dizziness, rashes, nausea and vomiting, chills and sensitivity to light.
The first ever deaths linked to the virus were reported in Brazil in July 2024, where two people died from the disease.
There is no cure, but there are preventative measures travellers can take like wearing long-sleeved clothing and using insect repellent to ward off midges.
These insect repellents need to be 50 per cent DEET—the active ingredient which repels pests like midges and mosquitos.
Other measures include staying in places with air conditioning or window screens with fine mesh to keep out midges and using insecticide-treated fine mesh bed nets.
So far this year, globally, there have been over 12,000 confirmed cases of the virus, with the majority (11,888) in Brazil.
The disease was first discovered in the 1950s in Trinidad and Tobago, and is endemic to the Amazon region according to the UKHSA.
Since then, it has been found in countries across Central and South America, including Brazil, Peru, Argentina, Bolivia, Colombia, and Panama.
In 2024 a number of outbreaks occurred in these countries, as well as in Cuba and Barbados. In 2025, cases were identified in Venezuela for the first time.
Signs and symptoms of Oropouche virus disease
- fever
- headache
- joint pain
- muscle aches
- chills
- nausea and vomiting
- rash
- sensitivity to light
- dizziness
- pain behind the eyes
