Retrovirus infections of the nervous system.

Mammalian retroviruses of all three subfamilies infect the nervous system. The leukemia viruses (oncovirinae) and lentiviruses (lentivirinae, eg, human immunodeficiency virus) cause serious disease, while the foamy viruses (spumavirinae) have not yet been shown to cause any disease. This review illustrates these diseases by referring particularly to three viruses: the human and murine leukemia viruses (human T-cell leukemia-lymphoma virus type I and murine leukemia virus), and the human immunodeficiency viruses, HIV-1 and 2. Other lentiviruses cause important encephalitides in other animals, notably cats (feline immunodeficiency virus), sheep (maedi/visna virus), and goats (caprine arthritis/encephalitis virus).