Dengue is an infectious disease caused by a virus. The virus is transmitted by a type of mosquito (Aedes aegypti) that bites during daylight hours.
The dengue virus belongs to the Flaviviridae family of viruses that cause diseases in humans. Dengue is the most common infection caused by viruses transmitted by mosquitoes (these are known as arboviral illnesses).
Dengue causes severe flu-like symptoms, such as:
- a high temperature (fever) of 40C (104F) or over
- severe headache
- muscle and joint pain
- facial flushing and skin rash
For more information, see Dengue - symptoms.
Who is at risk?
Anyone can catch dengue if the disease is common in that area (endemic). See the box, below left, for a list of high-risk countries.
However, dengue is more common among older children, adolescents and adults. The risk of travellers catching dengue depends on several factors, including:
- the countries they visit
- how long they stay in an endemic area (although even short-term visitors may be vulnerable to dengue)
- the season of travel (mosquitoes breed in fresh-standing water, such as puddles and collected rainwater)
- the intensity of dengue transmission in that area
Dengue is not naturally transmitted in the UK. However, a small number of cases have occurred in UK residents who had previously visited countries where the virus is endemic.
Dengue is a self-limiting disease. Self-limiting means that it clears up by itself, usually within a couple of weeks. The incubation period (the time it takes for symptoms to show after infection) for dengue is five to eight days.
There is no vaccine to prevent you becoming infected, although research into developing a vaccine to protect against dengue is in progress.
The only way to prevent getting the virus is to avoid being bitten and to be particularly careful around the hours of dawn and dusk. See Dengue - prevention for more information on how to avoid insect bites.
There are no specific medications available to treat the disease, but symptoms can be managed by taking paracetamol, drinking plenty of fluids and resting.
Most people with dengue recover within two weeks. However, in some cases dengue can develop into dengue haemorrhagic fever (DHF). This is a potentially fatal complication of dengue where you bleed from your nose, gums and inside your body. It can also lead to dengue shock syndrome (DSS), a serious complication of dengue haemorrhagic fever that can lead to shock (a sudden loss in blood pressure). This is also potentially fatal. For more information, see Dengue - complications.