Pathogenesis of dengue virus infections

Abstract

Aspects of the primary and the secondary infections by dengue viruses are analyzed in this revision article. Two kinds of answers of the immune system to dengue virus infections are described. One of them is beneficial to the patient and impedes further viral reinfections, the other immune answer induces the antibody dependent enhancement of dengue virus infection in macrophages which is important for starting the physiopathologic mechanism of the dengue hemorrhagic. The dengue hemorrhagic is consequence of an anomalous answer of the immune system involving leukocytes, cytokynes and immunocomplexes, causing increase of the vascular permeability without endothelial cell destruction. The increased vascular permeability induces leaking of liquids from the intravascular to the tissue intersticium, causing fall of the blood arterial pressure and hemorrhagic symptoms associated to trombocytopenia.