Evidence for polyomaviruses in human neurological diseases.

Polyomaviruses have been implicated in several chronic human neurological diseases. In progressive multifocal leukoencephalopathy there is an opportunistic and lytic infection of oligodendrocytes of the central nervous system leading to subacute demyelinating disease. Although aspects of the pathogenesis remain undefined, the causal role of the viruses seems firm. Nonpermissive infection of neural cells with resultant cerebral tumors has been suggested by epidemiological studies, virus isolations, and detection of viral antigens and nucleic acids. Nevertheless, it is uncertain whether papovaviruses are causally related to human tumors. Possible association of papovavirus infection with other neurological diseases needs further study.