coup d'Ã©tat. a sudden and decisive action in politics, especially one resulting in a change of government illegally or by force. Origin of coup d'Ã©tat.
The human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).AIDS is a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive.he human immunodeficiency virus (HIV) is a lentivirus (a subgroup of retrovirus) that causes HIV infection and acquired immunodeficiency syndrome (AIDS).
AIDS is not a disease per se but rather the stage of HIV infection where the body's immune system is severely compromised. Technically, AIDS is defined by either a CD4 count of under 200 cells per microliter (ÂµL) or by the diagnosis of a so-called AIDS defining illness.