The human immunodeficiency virus (HIV) causes HIV infection and acquired immunodeficiency syndrome over time (AIDS). AIDS is the condition of an organism in which a progressive decline in the immune system allows dangerous infections and the inability of an organism to naturally defend itself from them. HIV infects vital cells in the human immune system. Controlling HIV / AIDS usually involves the use of several antiretroviral drugs, both because of the different types of organism in humans, and because of the resilience of the virus acquired during treatment with the same drugs. In some parts of the world, treatments have become so successful that HIV has become a chronic condition, with very rare progress in AIDS.
