The first decade of human retroviruses: a nomenclature for the clinician

The decade of the 1980s has provided at least 10 terms for human retroviruses, of which five are currently recognized as defining distinct human infectious disease agents. Of these five, three are human T-cell lymphotropic viruses (HTLV-I, HTLV-II, HTLV-V) and two are human immunodeficiency viruses (HIV-1, HIV-2). HIV-1 and HIV-2 can cause the acquired immunodeficiency syndrome (AIDS), whereas HTLV-I, HTLV-II, and HTLV-V do not. HTLV-I can cause a T-cell leukemia/lymphoma as well as a progressive myelopathy. Disease(s) caused by HTLV-II and HTLV-V have yet to be conclusively established. Screening of the blood supply in the United States is currently designed to detect two of these retroviruses (HIV-1, HTLV-I). This review seeks to clarify the nomenclature of human retroviruses as we begin the second decade of their recognition.