Can you help give me some few facts on HIV/ AIDS ?

Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain infections and cancers. Initial infection may produce nonspecific febrile illness. The risk of subsequent manifestations—related to immunodeficiency—is proportional to the level of CD4+ lymphocytes. Manifestations range from asymptomatic carriage to the acquired immune deficiency syndrome (AIDS), which is defined by serious opportunistic infections or cancers. HIV infection is diagnosable by antibody or antigen testing. Treatment aims to suppress HIV replication by combinations of drugs that inhibit HIV enzymes.