[Dengue. A review]

Dengue fever is an acute and infectious disease produced by a togavirus. This clinical syndrome being benign or severe like the Dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS), has been associated with a very high mortality rate specifically in children with different ages and those under 1 year of age from mothers having antibodies to dengue virus. Other groups with potential risk factors are those patients with chronic diseases like asthma, sickle cell anaemia and diabetes mellitus. Dengue virus show a highly tropism for endothelial reticulum system as the bone marrow, spleen, liver and lymph nodes where viral antigens can be demonstrated by several immunological methods. The pathogenesis of the DHF/DSS can be considered to result from a delayed type hypersensitivity reaction where antigen-activated T lymphocytes release a variety of biologically active chemical mediators (lymphokines) with further effects on blood clotting system and vascular permeability producing the symptoms of shock and hemorrhage seen in these cases. The rapid control and hospitalization of the patients allow them to get a fast recovery without any sequelae.