 
         
         Summary
         
         Dengue viruses (DENV), a group of four serologically distinct but related flaviviruses,
            are the cause of one of the most important emerging viral diseases. DENV infections
            result in a wide spectrum of clinical disease including dengue haemorrhagic fever
            (DHF), a viral haemorrhagic disease characterised by bleeding and plasma leakage.The
            characteristic feature of DHF is the transient period of plasma leakage and a haemorrhagic
            tendency. DHF occurs mostly during a secondary DENV infection. Serotype cross-reactive
            antibodies and mediators from serotype cross-reactive Dengue-specific T cells have
            been impli-cated in the pathogenesis. A complex interaction between virus, host immune
            response and endothelial cells likely impacts the barrier integrity and functions
            of endothelial cells leading to plasma leakage. Recently the role of angiogenic factors
            and the role of dengue virus on endothelial cell transcription and functions have
            been studied. Insights into the mechanisms that confer protection or cause disease
            are critical in the development of prophylactic and therapeutic modalities for this
            important disease.
         
         Keywords
Dengue viruses - Dengue haemorrhagic fever - plasma leakage - permeability - immune
            system