RT Book, Section A1 Bookstaver, P. Brandon A2 Sutton, S. Scott SR Print(0) ID 1158314605 T1 Human Immunodeficiency Virus T2 McGraw-Hill's NAPLEX® Review Guide, 3e YR 2019 FD 2019 PB McGraw-Hill Education PP New York, NY SN 9781260135923 LK accesspharmacy.mhmedical.com/content.aspx?aid=1158314605 RD 2024/03/29 AB The human immunodeficiency virus (HIV or HIV-1) is a retrovirus that causes the acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune system leads to life-threatening opportunistic infections. A second retrovirus, HIV-2, also is recognized to cause AIDS, although it is less virulent, transmissible, and prevalent than HIV-1. Modern antiretroviral regimens have decreased the morbidity and mortality of HIV; however, HIV infection cannot be cured due to the integration of the HIV genome into host cells, creating a latent reservoir. An AIDS diagnosis is made when the presence of HIV is laboratory-confirmed and the cluster of differentiation 4 (CD4 cell) count drops below 200 cells/mm3 (200 × 106/L) for those older than or equal to 6 years of age or after the development of an opportunistic infection.