Dengue and dengue hemorrhagic fever.

Continued geographic expansion of dengue viruses and their mosquito vectors has seen the magnitude and frequency of epidemic dengue/dengue hemorrhagic fever (DF/DHF) increase dramatically. More than 200,000,000 infections and over 2 million cases of DHF occur annually, and dengue is one of the most important emerging tropical diseases in the world. Its dramatically increased incidence and geographic expansion is driven by unprecedented urbanization in tropical developing countries, globalization and lack of public health infrastructure to prevent and control epidemic disease.