Basic and clinical aspects of human cytomegalovirus infection.

The 1980s brought a story in the setting of the emerging disease AIDS. Here, retinitis, gastrointestinal disease, and nervous system infection predominated. Cytomegalovirus (CMV) is an enveloped double-stranded DNA virus in the beta subgroup of the herpesvirus family. Well-documented shedding of virus in human breast milk, urine, saliva, tears, semen, and cervical secretions, some of which occurs in healthy hosts, suggests that epithelial cells may harbor latent but reactivatable virus. Autopsy studies of homosexual men with AIDS have shown that multiple strains of CMV can infect different tissues. Longitudinal serial isolates from homosexual men show that 29% have two or more strains and semen was the most common site of viral shedding (40%). The pathology of CMV radiculomyelitis usually consists of inflammation and necrosis, with typical cytomegalic inclusion cells in the lumbosacral roots. The broad spectrum of observed central nervous system (CNS) disease in AIDS is likely related to a broader range of viral load secondary to the immunodeficiency. The hematogenous-endothelial mode of entry is postulated to lead to diffuse disease. There is one report of its successful use in AIDS-associated ventriculoencephalitis with both clinical improvement and reversion of CSF to CMV negative by PCR.