Emergence of epidemic dengue/dengue hemorrhagic fever as a public health problem in the Americas.

The incidence of dengue and dengue hemorrhagic fever has increased dramatically in the past 15 years in most urban centers of the tropics. Coincident with this increase has been the emergence of epidemic dengue hemorrhagic fever in the American region. The current changing disease pattern in the Americas is very similar to that which occurred in southeast Asia 30 years ago. The similarities in the evolution of severe disease in the two regions and the possible reasons for the changing disease pattern are discussed.