Dengue is one of the most common mosquito-borne infections that UK travellers pick up abroad. There is now a vaccine available in the UK, but it isn’t for everyone, and the rules on who can have it have changed. Here is a plain-English guide.
What is dengue?
Dengue is a viral infection spread by the bite of an infected mosquito. The mosquitoes that carry it usually breed in towns and cities, close to where people live, and they are most active during the day.
Dengue is common in the tropics, including the Caribbean, South and Central America, Africa, Asia and the Pacific Islands. Outbreaks are also increasingly reported outside tropical areas. Locally acquired cases have been reported in Europe, in Croatia, France, Italy, Madeira and Spain. Dengue doesn’t occur naturally in the UK, but cases in returning UK travellers are increasing, mostly from Asia, Central and South America and the Caribbean.
Recent outbreaks reported by TravelHealthPro include:
Malaysia: 56,319 cases reported in 2026 (as of 12 August)
Bangladesh: 17,880 cases and 59 deaths (as of 6 August 2026)
India: 22,938 cases (as of 13 July 2026)
What are the symptoms?
Between 40 and 80 percent of people who are infected have no symptoms at all. When symptoms do appear, they usually start suddenly with a high fever, often with a severe headache, muscle and joint pain, nausea, vomiting and a rash. Most people recover within a few days of the rash appearing.
A small number of people develop severe dengue. This can cause dangerously low blood pressure (shock), fluid on the lungs and severe bleeding. There is no specific drug for severe dengue, but hospital care to manage fever, fluids and pain helps recovery. With good medical care, death from severe dengue is typically less than one percent. Severe dengue is rare in travellers.
The four types of dengue
There are four types of the dengue virus, called DENV-1, DENV-2, DENV-3 and DENV-4. You can catch dengue more than once. UK guidance notes that the risk of severe dengue is higher with a second infection, which is why the question of who should be vaccinated is not as simple as it sounds.
Who is at risk?
Anyone travelling to a dengue-affected country can catch it. Your risk depends on where you go, how long you stay and the time of year. Long stays increase risk, but even short-term visitors can be infected.
Dengue before and after the vaccine
Not so long ago, there was no dengue vaccine available in the UK, so avoiding mosquito bites was the only protection. People who had already had dengue had good reason to be cautious about returning to risk areas, because a second infection carries a higher chance of severe disease.
A vaccine called Qdenga is now licensed in the UK for people aged 4 years and over. It is a live vaccine, which means it contains weakened dengue virus.
Who can have the dengue vaccine?
When UK guidance on Qdenga was first published in 2024, it was recommended only for people aged 4 and over who had already had dengue and were travelling to a risk area, or who were exposed to the virus through their work, for example laboratory staff. People who had never had dengue were not advised to have it.
TravelHealthPro’s current advice says the vaccine can still be considered for those with a confirmed or likely previous dengue infection. It also says vaccination can be considered in people who have never had dengue, but only after a discussion with a travel health clinician experienced in weighing the possible risks and benefits. This is a decision to make with a clinician, not a walk-in vaccine.
How do we know if you’ve had dengue before?
It isn’t always straightforward. Blood tests for previous dengue infection may not be 100 percent reliable. Your clinician will look at any earlier test results, where you’ve travelled and your medical history. In the UK these blood tests are usually offered privately, and there is a fee.
Who can’t have the vaccine?
Because Qdenga is a live vaccine, it cannot be given to:
People who are pregnant or breastfeeding
People with a weakened immune system
Children under 4 years old
Anyone with an allergy to any component of the vaccine, including anyone who has had a severe allergic reaction to a previous dose
The vaccine course is two doses, given three months apart, so plan well ahead of your trip.
Bite avoidance is still essential
Even if you’re vaccinated, avoiding bites matters. Dengue mosquitoes bite during the day, and the risk is thought to be highest in the two to three hours after dawn and in the early evening. That is different from malaria mosquitoes, which bite mainly at night.
Use an effective insect repellent during the day, not just at night
Wear long, loose clothing, especially around dawn and dusk
Take extra care in towns and cities, where these mosquitoes breed near people’s homes
Check TravelHealthPro’s country page for your destination before you travel
Next steps
Whether you’ve had dengue before or never, the best way forward is a personal assessment of your destination, dates and history. Book a travel consultation at Trustwell Clinic, and aim to come at least 3 months before you travel so there is time for two doses.
Trustwell Clinic, 72a Stockport Road, Marple, SK6 6AH
Tel: 0161 883 7522
www.trustwellclinic.co.uk
Sources: TravelHealthPro (NaTHNaC) dengue pages and outbreak updates, and the UKHSA Green Book dengue chapter (chapter 15a) as summarised by TravelHealthPro. This article is general information, not an individual risk assessment.