Dengue

Dengue virus is the causative agent of dengue fever and dengue hemorrhagic fever (DHF).

This Virus belongs to the flavivirus family (Flaviviridae). It shows an icosahedral capsid and closefitting, spiked envelope. The size of the capsid is about 30 nm and the whole virion measures 50 nm. 4 different serotypes exist (DEN-1, DEN-2, DEN-3 and DEN-4), whereas an infection of one serotype doesn?t lead to an immunity against the other serotypes.

Humans are the only known main hosts for the Dengue virus. The pathogen is transmitted by mosquitoes (Aedes aegypti). The virus causes diseases of different levels of severity. The infections are typically biphasic with an initial, not very characteristic phase, including fever, headache, muscle pain and - in some cases - exanthema (Dengue fever). This phase includes a pronounced viremia. The illness, in this stage often not recognized as a dengue virus infection, may then be over or may progress after 1-3 days to a second, severe clinical picture: a hemorrhagic fever with a high lethality rate involving hemorrhages and intravasal coagulation, so called Dengue hemorrhagic fever or Dengue shock syndrome, depending on the predominant characteristics (see table).

In southern and eastern countries (mainly in West Africa, Pacific, South and Southeast Asia, Caribbean, Venezuela, Colombia and Brazil) these viruses are significant human pathogens.