HIV y HTLV: dos retrovirus que interfieren con el sistema inmune

human immunodeficiency virus ( hiv) and human t-cell leukemia virus are retroviruses they infect cells of immune sistem and so alter the natural function of the immune sistem that is defense against microrganisms, such as bacteria, viruses, fungi and parasites and survillance against altered self cells. the immune sistem is part of higher animal's body, such as mammals and due these viruses infect t cell and the long and permanent infection the clinical course sickness appears and take to individual to death. this paper describe on general way how does infection occur and go on.