Dengue fever is a mosquito-borne infection that causes a severe flu-like illness. The virus is not contagious and cannot be spread directly from person to person.

Cause

The virus is spread by the bite of dengue-infected female Aedes mosquitoes which bite mostly at dawn and dusk. The mosquitoes flourish during rainy seasons but can also breed in water-filled flower pots, plastic bags and cans year-round. One mosquito bite can cause the disease.

Aedes mosquitoes are found in tropical and sub-tropical climates worldwide, mostly in urban and semi-urban areas. Infected humans are the main carriers and multipliers of the virus, serving as a source of the virus when uninfected mosquitoes bite the human carrier.

Symptoms

Dengue fever usually begins with a sudden onset of a high fever and a severe headache. Those affected may also suffer from skin rash, swollen glands and severe muscle and joint pain, as well as from nausea, vomiting and loss of appetite. The presence of fever, rash and headache is particularly characteristic of dengue fever. The illness lasts up to 10 days, but recovery may take some time and sufferers can feel tired and depressed for weeks.

Sometimes a potentially fatal complication, called dengue haemorrhagic fever, can develop in people who have been infected repeatedly.

Treatment

Dengue fever is diagnosed by a combination of typical symptoms and blood tests. There is no specific treatment for dengue fever, but proper medical care frequently saves the lives of people who suffer the more serious dengue haemorrhagic fever.

Prevention

There is no vaccine to protect against dengue fever and no medicine to prevent it. However, the following are things you can do to protect yourself:

    • Wear clothing that covers arms and legs
    • Wear hats and shoes (not sandals)
    • Apply insect repellent to skin
    • Apply permethrin insecticide to clothes
    • Use mosquito nets soaked with permethrin
    • Use electric insect-repellent devices or mosquito coils
    • When possible, stay in accommodation that has screens on doors and windows or is air-conditioned
    • Limit exposure to mosquitoes by avoiding standing water and staying indoors two hours after sunrise and before sunset.

The prevention of dengue fever requires control or extermination of the mosquitoes carrying the virus. Global occurrence of dengue has grown dramatically in recent decades. The disease is now endemic in more than 100 countries in Africa, the Americas, the Eastern Mediterranean, South-east Asia and the Western Pacific.