Dengue fever is a mosquito-borne viral infection (genus Flavivirus) causing fever, severe joint pain and, in some cases, hemorrhage, shock, and in the most severe cases, death. It is found in tropical and sub-tropical regions and it affects 50 million people across five continents, and infection rates are increasing dramatically. Presently, there is no known cure or vaccine for this disease.
 

• There are four distinct, but closely related, viruses that cause dengue.
• Recovery from infection provides lifelong immunity against one virus but not against the other three serotypes.
• An estimated 500,000 cases require hospitalization each year; a large proportion of which are children.
  
• DHF case fatality rates can exceed 20%.
   

Vaccine development and chemotherapy for Dengue and DHF are difficult, in particular the development of vaccines that may protect against all four strands of dengue viruses, rather than just one.