‘Sloth virus’ arrives in UK for first time as deadly Oropouche symptoms revealed

The latest figures from the UK Health Security Agency (UKHSA) show a surge in travel-related chikungunya infections across England, with 73 cases recorded between January and June 2025

A mystery “sloth virus” has been identified in the UK for the first time, following its spread across Europe. The most recent data, unveiled today by the UK Health Security Agency (UKHSA), disclosed three instances of the Oropouche virus, also known as “sloth fever”, in travellers returning to the UK.

This marks the first time the Oropouche virus has been found on British soil, with all cases associated with trips to Brazil. The latest statistics from the UK Health Security Agency (UKHSA) also indicate a spike in travel-related chikungunya infections throughout England.

From January to June 2025, 73 cases were logged – a significant increase from the 27 cases recorded during the same period in 2024, representing the highest count ever noted for this timeframe.

This follows the quiet spread of Oropouche across the continent, which could prove more perilous than initially anticipated.

Chikungunya is a disease transmitted by mosquitoes and linked to international travel, typically manifesting as sudden fever and joint pain, reports the Mirror.

Out of the 73 chikungunya cases, the majority reported travel to Sri Lanka, India and Mauritius, correlating with ongoing local outbreaks in countries in the Indian Ocean region. All cases were reported in England, predominantly in London.

Dr Philip Veal, Consultant in Public Health at UKHSA, explained: “Chikungunya can be a nasty disease and we’re seeing a worrying increase in cases among travellers returning to the UK.

“While this mosquito-borne infection is rarely fatal, it can cause severe joint and muscle pain, headaches, sensitivity to light and skin rashes. Thankfully symptoms usually improve within a few weeks, but joint pain may last for months or longer.

“It is essential to take precautions against mosquito bites when travelling. Simple steps, such as using insect repellent, covering up your skin and sleeping under insecticide-treated bed nets can greatly reduce the risk.

“Before you travel, check the Travel Health Pro Website for the latest advice on your destination. A chikungunya vaccine may also be considered for those travelling to higher-risk regions.”

What is Oropouche virus?

Oropouche virus (OROV) is transmitted mainly through midge bites instead of mosquito bites. The main variety of midge behind the outbreak across the Americas isn’t found in the UK and Europe.

Anyone who falls ill with symptoms including high fever, chills, headache, joint pain and muscle aches after visiting affected regions should seek urgent medical advice.

How does the virus spread?

Since 2024, there’s been a global surge in Oropouche virus infections, particularly in various South American, Central American and Caribbean countries. Brazil has reported the most significant outbreaks.

Given the uptick in cases and recent concerns about Oropouche virus infection during pregnancy, expectant travellers are advised to exercise extra caution.

Oropouche symptoms

The onset of symptoms is typically sudden, with fever often accompanied by joint pain.

While the majority of patients recover fully within a fortnight, the joint discomfort can linger for months or even years in some instances, with up to 12% of patients still feeling discomfort three years post-infection.

Serious complications are rare, but in exceptional cases, the disease can prove fatal, especially among the very young, the elderly, and those with pre-existing health conditions.