ABSTRACT
The acquired immunodeficiency syndrome (AIDS) viruses belong to a group of viruses known as retroviruses or backward viruses. The retroviruses are ribonucleic acid (RNA) viruses which require an enzyme called reverse transcriptase for successful replication. Characteristically, the retroviruses can be subdivided into two groups: oncogenic viruses or lentiviruses. The AIDS viruses are primarily a group of simian or monkey retroviruses.
