ABSTRACT
Dengue viruses are mosquito-borne viruses which exist in nature as four separate types. These are enveloped ribonucleic acid viruses belonging to the family Flaviviradae, of which yellow fever virus is the type species. There is a continuum of response in dengue-infected human beings from a mild, undifferentiated fever to fatal shock syndrome. Mild dengue infections produce clinical syndromes which vary according to age. A crucial question in dengue research has been to determine why there exist dengue syndromes which differ in physiology and prognoses. In countries exhibiting the full spectrum of clinical responses to dengue infection, a small percentage of dengue shock syndrome (DSS) cases in children were thought to be caused by primary dengue infections. Preliminary analysis of data from Thailand suggests that preillness neutralizing antibody titers are lower in children who develop DSS than in children who are secondarily infected, but do not develop overt disease.
