The UK Health Security Agency (UKHSA) has issued a health alert after an increase in imported cases of chikungunya and, for the first time, Oropouche virus. The warning comes as international travel rebounds and mosquito-borne illnesses gain ground in traditionally non-endemic areas.
Both viruses are transmitted through insect bites and cannot be passed from person to person, but the risks they pose—especially to vulnerable groups—are being taken seriously by public health authorities.
Imported Chikungunya Cases Triple Compared to Last Year
According to the UKHSA, 73 cases of chikungunya have been recorded in the UK from January to June 2025. This marks a significant rise compared to 27 cases during the same period in 2024. The majority of these recent cases were detected in London and were linked to travel to Sri Lanka, India, and Mauritius.
The chikungunya virus is transmitted by the Aedes mosquito, which is not present in the UK, meaning all infections were acquired abroad. Symptoms typically include fever, rash and severe joint pain, which in some cases may persist for months or even years.
Dr Philip Veal, Consultant in Public Health at the UKHSA, described the rise as “worrying”, noting that the resurgence of vector-borne viruses in global hotspots coincides with a notable increase in overseas travel. “Simple steps, such as using insect repellent, covering up your skin and sleeping under insecticide-treated bed nets can greatly reduce the risk.” he said.
Though chikungunya is commonly found in parts of Asia and Africa, there has been a documented spread into parts of Europe and North America this year, suggesting wider ecological changes and vector migration.
First Oropouche Cases Confirmed in Returning Travellers
The UK has also recorded its first known cases of the Oropouche virus, with three confirmed infections in travellers returning from Brazil. The virus, identified in the 1950s in Trinidad and Tobago, is spread by mosquitoes and midges, and was once largely confined to the Amazon basin. It is now being detected more frequently in Dominican Republic, Cuba, and Peru.
Symptoms of Oropouche include fever, headache, muscle pain, joint pain, and vomiting. While most individuals recover without treatment, the illness can be more serious in elderly individuals or those with weakened immune systems.
The UKHSA is advising travellers returning from Central America, South America, or the Caribbean to seek medical advice if they experience flu-like symptoms. Vaccines for chikungunya are currently available through private travel clinics in the UK, but there is no approved vaccine or specific treatment for Oropouche at this time.
Health authorities emphasise that preventive measures remain the most effective defence. With vector-borne diseases no longer confined to the tropics, public health guidance is adapting to a rapidly changing global risk landscape.
