Surge in Chikungunya cases among UK travelers

London: Travel-associated chikungunya cases in England have almost tripled this year, according to the UK Health Security Agency (UKHSA).

Between January and June 2025, 73 cases were reported compared with 27 in the same period in 2024 — the highest number recorded for this timeframe. The majority were linked to travel to Sri Lanka, India, and Mauritius, where local outbreaks are ongoing. Most of the reported cases were in London.

For the first time, cases of Oropouche virus were also confirmed in UK travellers. All were linked to travel to Brazil.

The UKHSA report “Travel-Associated Infections in England, Wales and Northern Ireland: January to June 2025” also found:

Cholera: Eight cases were reported, compared with one in 2024. Most had travelled to India and Ethiopia, with all Ethiopia-linked cases tied to an outbreak there.

Meningococcal disease (MenW): Cases were linked to travel to Saudi Arabia for Umrah and Hajj, and to household contacts of returning travellers.

Dengue: Cases fell by 67% to 161, compared with 490 last year.

Zika virus: Four cases were reported, down from nine in 2024.

Chikungunya Outbreaks Widen

Chikungunya is a mosquito-borne viral infection found mainly in Africa and Asia, with cases also reported in parts of Europe and North America.

This year, large outbreaks have been seen in the Americas and Asia, with notable surges in China and on the Indian Ocean islands of Réunion, Mayotte, and Mauritius.

“We’re seeing a worrying increase in cases among travellers returning to the UK,” said Dr Philip Veal, consultant in public health at UKHSA. He described chikungunya as a “nasty” disease that, while rarely fatal, can cause severe joint and muscle pain, headaches, sensitivity to light, and skin rashes. Symptoms usually resolve within weeks, but joint pain can persist for months or years. Up to 12% of patients still experience discomfort 3 years after infection.

UKHSA stressed that the mosquitoes which transmit chikungunya are not established in the UK due to the climate, so there is currently no risk for local transmission. The agency said there is “no risk of onward transmission of chikungunya in the UK.”

Oropouche virus is spread mainly by midge bites. Since 2024, infections have increased across South America, Central America, and the Caribbean, with Brazil seeing the largest outbreaks.

The species of midge responsible for transmission in the Americas is not found in the UK or Europe.

The disease often starts suddenly, with fever, chills, headache, joint pain, and muscle aches. Symptoms typically last up to 7 days, though in some cases it can cause meningitis or encephalitis.

The UKHSA has advised pregnant travellers to take particular care due to recent concerns about infection during pregnancy.

“It is essential to take precautions against mosquito bites when travelling,” said Veal. Measures include using insect repellent, covering exposed skin, and sleeping under insecticide-treated nets.

Travellers to high-risk areas may also consider vaccination. Two chikungunya vaccines have recently been approved for UK use, based on Joint Committee on Vaccination and Immunisation advice. They are available privately through travel clinics after assessment by a healthcare professional.

The UKHSA also reminded travellers to Saudi Arabia for pilgrimage to ensure they are vaccinated with the MenACWY vaccine before departure.