DISEASES ASSOCIATED WITH CONVENTIONAL AGENTS
The following conditions are the major persistent infections caused by conventional viral agents. They are summarized in Table 44–1.
Subacute sclerosing panencephalitis, It is a rare chronic measles virus infection of children that produces progressive neurologic disease charac-terized by an insidious onset of personality change, progressive intellectual deterioration, and both motor and autonomic nervous system dysfunctions.
Even more rarely, a degenerative neurologic disorder similar to subacute sclerosing pan-encephalitis may be related to persistent rubella virus infection of the central nervous sys-tem (CNS). This condition is seen most often in adolescents who have had the congenital rubella syndrome. Rubella virus has been isolated from brain tissue in these patients us-ing cocultivation techniques.
Progressive multifocal leukoencephalopathy (PML) is a subacute, degenerative disease of the brain found primarily in adults with (1) immunosuppressive diseases, especially acquired immunodeficiency syndrome (AIDS) and reticuloendothelial malignancies; or (2) diseases requiring therapy with immunosuppressive agents. PML is due to a papova-virus.
Persons with congenital or severe acquired immunodeficiency, especially those with agammaglobulinemia, may develop a chronic CNS infection due to an echovirus or other enterovirus. Headache, confusion, lethargy, seizures, and cerebrospinal fluid (CSF) pleo-cytosis are common manifestations. The virus can be isolated from the CSF. Clinical im-provement may be achieved by the administration of human hyperimmune globulin to the infecting virus type. Relapse, however, occurs if therapy is discontinued, indicating per-sistence of virus despite the therapy.
Human immunodeficiency virus causes a persistent infection of the CNS in many patients with symptomatic AIDS. The clinical course may vary from a mild subacute illness to se-vere progressive dementia .