Introduction
Dengue is the most common mosquito-borne viral disease of humans that in recent years has become a major international public health. Globally, 2.5 billion people live in areas where dengue viruses can be transmitted. The geographical spread of both the mosquito vectors and the viruses has led to the global resurgence of epidemic dengue fever (DF) and emergence of dengue hemorrhagic fever ( DHF ) in the past 25 years with the development of hyperendemicity in many urban centers of the tropics.
DHF was first recognized in the 1950s during the dengue epidemics in the Philippines and Thailand. By 1970 nine countries had experienced epidemic DHF and now, the number has increased more than fourfold and continues to rise. DHF has become a leading cause of hospitalization and death among children in several countries.