Rise in mosquito-bourne chikungunya infection in returning travellers

The UK has been alerted to a ‘worrying’, though still small, increase in cases of the mosquito-borne disease chikungunya in travellers returning with the infection following a trip abroad.

There have been 73 cases in the first six months of the year in England, the UK Health Security Agency said, compared with 27 cases in the same period in 2024.

It is the highest number of chikungunya cases ever seen in England and reflects ongoing outbreaks overseas.

Among the cases this year, most had travelled to Sri Lanka, India and Mauritius due to outbreaks across the Indian Ocean region, the figures show.

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Spread by mosquitoes, the symptoms of chikungunya include a sudden onset of fever usually accompanied by joint pain.

Most people recover fully within a couple of weeks but for some the joint pain can persist for months or even years.

Up to 12% of patients still experiencing discomfort three years after infection, UKHSA said.

The two types of mosquitoes that spread chikungunya are not yet established in the UK and there is currently no risk of onward transmission, experts said.

Two vaccines against the infection have been approved by the Joint Committee on Vaccination and Immunisation but they are only available privately through travel clinics.

In a statement published in July, the JCVI said there had also been outbreaks in France and Italy.

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The presence of Aedes mosquitoes in European countries, and importations from infected travellers returning from endemic countries, means that the likelihood of spread in mainland Europe is high, it noted.

There have been reports of more than 7,000 cases of chikungunya in China’s Guangdong province since July, prompting strict infection control measures in the region.

A UKHSA report on travel-associated infections also found that Oropouche virus disease, which is spread by midge bites, was reported for the first time in England, Wales and Northern Ireland, with three imported cases linked to travel to Brazil.

Dr Philip Veal, consultant in public health at UKHSA, said: ‘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.’

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He urged people to take precautions against mosquito bites when travelling, including using insect repellent, covering up and sleeping under insecticide-treated bed nets.

This article was initially publish by our sister publication Pulse.