Dengue fever is present in Asia, the Pacific, the Caribbean, the Americas and Africa. Humans are infected with dengue virus through bites of tiger (Aedes) mosquitoes. There are 4 different dengue types, and infection with one type gives little immune protection against the other types. After an incubation of 8-10 days, a mild and usually self-limited flu-like illness develops. Current scientific evidence shows that sequential infection increases the risk of a severe form of the infection with bleedings - dengue hemorrhagic fever.
In several Asian countries, dengue haemorrhagic fever has become an important cause of disease and death, mainly in children. No specific treatment or vaccine exists for dengue, and general intensive care is often needed.