Chikungunya: what travellers should know about this mosquito-borne virus

Chikungunya is a viral infection spread by the Aedes mosquito.

22 August 2025
5 min read
by The Conversation

All of the Chikungunya cases in England were associated with travel to regions which have had ongoing outbreaks of the virus. nechaevkon/ Shutterstock

The UK’s Health Security Agency has advised overseas travellers to take precautions to avoid contracting the potentially severe mosquito-borne virus, Chikungunya.

This warning was issued in response to recently published data, which shows that during the first six months of this year, there have been 73 reported cases of Chikungunya virus in England. Only 27 cases were reported during the same time last year. All of these infections were associated with travel to regions which have had ongoing outbreaks of Chikungunya virus, including Sri Lanka, India and Mauritius.

Chikungunya is a viral infection caused by the Chikungunya virus, which is almost always spread by Aedes mosquitoes. These mosquitoes usually breed in standing water, which means they generally live close to human populations. Unlike the mosquitoes that spread malaria, Aedes mosquitoes bite during the day.

A person infected with Chikungunya virus will usually start experiencing symptoms about four to eight days after the bite. The illness usually starts with a sudden high temperature, typically alongside severe joint pain. Other symptoms may include joint swelling, muscle pain, headache, nausea, fatigue and rash. Joint pain usually lasts a few days but can last for weeks, months and, in rare cases, years.

The infection is usually mild and almost all people recover without needing medical treatment. However, joint pain when it occurs can be very severe and can last long after the initial illness. Deaths from Chikungunya virus are rare. When they do occur, it’s usually in people over 60 years of age, or those who have other health conditions such as hypertension, heart disease and diabetes.

There is no treatment for the infection. Treatments, when needed, are limited to those which control the infection’s associated symptoms – such as fever or joint pain. Drugs such as paracetamol or ibuprofen would be used for joint pain.

Preventative measures are the most important step a person can take to avoid contracting Chikungunya virus.

There are currently two vaccines available which prevent Chikungunya. The UK currently recommends these vaccines are considered for people travelling to regions with active outbreaks or for long term visitors to regions which have had active transmission of the virus in the past five years.

There are two vaccine options in the UK: Vimkunya and IXCHIQ. Vimkunya can be offered to people aged 12 years and over. IXCHIQ vaccine can only be offered to people aged 18 to 59 years old. The use of IXCHIQ vaccine was recently suspended for people aged 65 years and over because of possible serious side-effects in this age group.

The other important preventative measure is avoiding mosquito bites – even during the day – by using insect repellents and wearing loose fitting clothing that cover most exposed skin.

Preventing mosquito bites will protect you from contracting Chikungunya. SeventyFour/ Shutterstock

But the best way to reduce risk is by controlling mosquito populations. The most effective and sustainable measures for doing this are those which reduce breeding sites close to home – such as covering water containers and removing objects where water can collect, such as old tyres.

Evidence for the effectiveness of other measures at preventing Chikungunya, such as chemical or biological treatments, is not strong.

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Safe travels

Over the past couple of years, there have been increasing reports of Chikungunya infections in Africa, South America, South East Asia and China. So it’s not surprising that Chikungunya virus infections have been increasing in England in returning travellers who had visited these regions.

What is particularly worrying is that we’re now seeing outbreaks of locally-transmitted Chikungunya infections in several parts of France and Italy. Although such outbreaks are not new – in fact, we’ve seen outbreaks in Europe in six out of the past 20 years – what is new is the number of localised outbreaks we’re seeing. This year, 27 clusters of localised transmissions have been recorded mainly in the south of France and northern Italy. Infection rates are still increasing.

France is clearly at risk for imported Chikungunya as Reunion Island in the Indian Ocean, one of its overseas territories, has been experiencing a particularly severe outbreak with 47,500 cases and 12 deaths between August 2024 and May this year. Reunion is a popular tourist destination particularly for French tourists. It is likely that many of the clusters we are seeing in France would be traced back to a returning traveller.

This summer’s heatwaves have been particularly severe and prolonged and this could be further increasing the risk of local transmission in Europe after an infection has been brought back. Work on dengue fever, a similar mosquito-borne infection, shows that for localised transmission to occur, you generally need daily temperatures of around 30°C to 35°C for several weeks.

The most likely explanation for the increase in Chikungunya in UK residents is the general global increase with travellers picking it up abroad. And if the outbreaks in France and Italy continue to spread, this could mean an even greater number of UK travellers might pick up Chikungunya virus.

It’s unlikely the UK will see localised transmission – though not impossible. We would need the very hot weather to continue for longer than we are seeing in the UK.

The best advice to remain safe from Chikungunya, and the similar but more lethal dengue fever, is to avoid mosquito bites. This is especially important for people over 60 or those who have existing medical problems.

If you’re planning on travelling to a region where there is an active Chikungunya outbreak, it’s advised you speak to your doctor about getting vaccinated. Where Chikungunya virus is present, use insecticides on exposed skin and wear loose fitting clothes that cover arms and legs.