Dengue

Dengue is a common viral infection spread by mosquitoes. It is widespread in tropical and sub-tropical regions.

Symptoms of dengue include:

a high temperature (fever) that can reach as high as 41C (105.8F)
headache
pain behind the eyes
bone, muscle and joint pain

You should see your GP if you develop a fever or flu-like symptoms within two weeks of returning from an area where the dengue virus is common. Alternatively, you can call NHS 111 for advice.

What causes dengue?

Dengue is spread by infected mosquitoes – most commonly the Aedes aegypti mosquito.

An infected human is bitten by a mosquito, the infected mosquito then bites another human, and the cycle continues.

The condition is widespread in areas of the world with a high mosquito population and has been spread by the trade in worn car tyres, which collect water where mosquitoes breed. Typically, dengue occurs in areas that have a combination of:

a warm and humid climate
overcrowding and major urban centres

The mosquitoes that spread dengue are rare in England, and cases that develop in the UK occur in travellers who picked up the infection overseas.

Dengue cannot be spread from one person to another.

Diagnosing dengue

If you have travelled to a country with dengue and develop symptoms after you return to the UK, go straight to your nearest healthcare professional (either a GP or hospital).

If you go to a local doctor familiar with dengue, they will probably be able to diagnose the condition just by looking at you and asking about your symptoms. Remember to tell them you have been travelling, as other tropical viruses may cause similar symptoms.

Your medical and travel history will be taken and you will be asked about your exposure to mosquitoes.

You will also be given a blood test to see what effect the infection has had on your blood, and to confirm whether the dengue virus is present in your bloodstream.

Treating dengue

Dengue usually clears up by itself within around one to two weeks.

There are no specific medications to treat the disease, but symptoms can be managed by taking paracetamol, drinking plenty of fluids and resting.

Read more about the treatment of dengue.

Complications

A very small number of people with dengue go on to develop a more serious form of the disease known as "severe dengue". Severe dengue is a potentially fatal complication of dengue that can lead to shock (a sudden drop in blood pressure), bleeding and organ damage.

People who get this complication will need to be admitted to hospital as a precaution.

Read more about the complications of dengue.

Prevention

There is currently no vaccine for dengue fever, so the best way to prevent catching the infection is to take common sense precautions when travelling in high-risk areas, such as:

wear protective clothing
using a mosquito repellent throughout the day

Read more about reducing your risk of getting dengue.

Who is affected

Anyone can develop dengue, and it is estimated that 100 million cases of dengue occur each year worldwide.

There can be sudden outbreaks of cases (epidemics) where thousands of people can become infected in a short space of time.

In 2013, there were 541 reported cases in England, Wales and Northern Ireland. Most of these cases were in people returning from destinations such as India, Thailand and Barbados.