1. What is dengue fever?
Dengue fever is caused by a group of closely related viruses that are transmitted between people by the Aedes aegypti mosquito. The World Health Organization (WHO) ranks dengue as the most important mosquito-borne viral disease in the world - and the most rapidly spreading - with a 30-fold increase in global incidence over the past 50 years.
Each year an estimated 390 million dengue infections occur with 500,000 of these developing into dengue haemorrhagic fever, a more severe form of the disease, which results in up to 25,000 deaths annually worldwide.
Dengue haemorrhagic fever (DHF) is a potentially fatal complication of dengue fever that is characterised by high fever and internal haemorrhaging, Today DHF affects most Asian countries and has become a leading cause of hospitalisation and death among children and adults in the region.
Currently there is no cure for dengue or effective way to control the spread of the virus, other than attempting to reduce mosquito breeding sites and applying insecticides.
2. When and where did dengue first originate?
Dengue became a widely established disease throughout the tropics with the development of commercial shipping during the 18th century. In the last 50 years, incidence of dengue fever has increased 30-fold. Many factors are responsible for this, however, it is clear that rapid population growth, urbanisation and increased international air travel have all been driving forces associated with the increase in people affected by dengue.
3. How is dengue fever transmitted to humans?
Dengue is transmitted to humans from the bite of the Aedes aegypti or more rarely the Aedes albopictus mosquito, both of which feed exclusively during daylight hours. The Aedes aegypti mosquito does not naturally have the dengue virus - it is transferred from a person sick with dengue. Therefore the transmission of the dengue virus cannot be spread directly from person-to-person without the aid of the mosquito.
4. Is there a cure or treatment for dengue?
Unfortunately, there is no effective vaccine for dengue. However, there are many ongoing vaccine research programs in various stages of development. There is also no specific medication for treating a dengue infection. People infected with the virus are commonly prescribed painkillers, advised to rest and to drink plenty of fluids. Those diagnosed with dengue are also asked to wear insect repellent to prevent the spread of the disease to other mosquitoes and potentially other people.
5. In what areas are people most at risk of being infected with dengue?
Dengue is considered endemic to the Americas, south-east Asia, western Pacific, Africa and the eastern Mediterranean. The most significant epidemics occur in south-east Asia, the Americas and the western Pacific.
6. What are the symptoms of dengue fever?
Classic dengue fever lasts about two to seven days, followed by a long recovery period. Typical symptoms may include but are not limited to:
- metallic taste in the mouth
- sudden onset of fever
- headache (usually behind the eyes)
- muscle and joint pain
- loss of appetite
- vomiting and diarrhoea
- flushed skin on face and neck
- rash on arms and legs and severe itching
- peeling of skin and hair loss
- minor bleeding (nose or gums) and heavy menstrual periods
- extreme fatigue
7. What should someone do if they suspect they might be infected with dengue fever?
If someone presents with the symptoms listed above they should immediately see a doctor.