Dengue is a viral infection spread by mosquitoes. There are two forms: dengue fever (an influenza-like illness) and dengue haemorrhagic fever, a serious disease that can be fatal.
Dengue fever is found in tropical regions in particular in Southeast Asia, Central and South America, on the islands of the Caribbean and in Africa. Each year, more than two billion people in more than one hundred countries are at risk of infection.
Dengue fever is an influenza-like illness with symptoms such as fever, severe headache, pain in muscles and joints, and a red rash. Nausea and vomiting are also possible. Dengue haemorrhagic fever, the more severe form of the disease, can in addition to the symptoms of the simpler form cause bruises, nosebleeds, bleeding gums, anxiety and a feeling of thirst. These can be followed by more severe bleeding, shock, and even death. Dengue haemorrhagic fever shock usually only occurs in travellers if they have previously been ill with dengue.
The virus is transmitted from person to person by mosquitoes (predominantly Aedes aegypti), which are small black-and-white insects. The first clinical symptoms usually occur after between eight and twelve days after the bite.
Travellers should stay away from stagnant water where the mosquitoes that spread the dengue virus thrive. These mosquitoes are more active during the day so it is wise to wear clothing that covers the entire body and the use of mosquito repellents (preferably containing DEET) is strongly recommended.
There are presently no vaccines or preventive medicines for dengue. Adults generally experience a complete recovery, though this can take some time. Children younger than ten years will need medical attention. Patients with dengue haemorrhagic fever shock should be taken to intensive care immediately: they are seriously ill.