Human Immunodeficiency Virus (HIV)
The virus that causes AIDS.
About HIV
HIV belongs to a class of viruses called retroviruses.
Retroviruses are RNA (ribonucleic acid) viruses, and to replicate (duplicate), they must make a DNA (deoxyribonucleic acid) copy of their RNA. It is the DNA genes that allow the virus to replicate.
Like all viruses, HIV can replicate only inside cells, commandeering the cell‘s machinery to reproduce. Only HIV and other retroviruses, however, once inside a cell, use an enzyme called reverse transcriptase to convert their RNA into DNA, which can be incorporated into the host cell’s genes.
HIV belongs to a subgroup of retroviruses known as lentiviruses, or “slow” viruses. The course of infection with these viruses is characterized by a long interval between initial infection and the onset of serious symptoms. NIH – National Institute of Allergy and Infectious Diseases