Revised November 1998

Dengue is a mosquito-borne infection which in recent years has become a major international public health concern. Dengue is found in tropical and sub-tropical regions around the world, predominately in urban and peri-urban areas. Dengue haemorrhagic fever (DHF), a potentially lethal complication, was first recognized during the 1950s and is today a leading cause of childhood mortality in several Asian countries. There are four distinct, but closely related, viruses which cause dengue. Recovery from infection by one provides lifelong immunity against that serotype but confers only partial and transient protection against subsequent infection by the other three. Indeed, there is good evidence that sequential infection increases the risk of more serious disease resulting in DHF.