HIV

Abstract

The rapid evolution and dire consequences of the HIV pandemic are unprecedented in the modern medical era. With societal mobilization against this viral threat and responsive biomedical research, in less than 50 years, our understanding and approach to HIV have transformed a fatal disease into a chronic disorder. However, in regions of greatest endemicity, there is an unmet need for access to care; accordingly, from a global perspective, HIV-related systemic and nervous system disorders fall into a spectrum of treated and untreated disease.

As a prelude to understanding CNS infection, this chapter will review the history and epidemiology of the HIV pandemic, its genetic evolution and molecular biology, and the HIV life cycle and natural history of untreated disease. It will then describe the clinical manifestations and neuropathology of HIV-associated neurocognitive disorder (HAND), pediatric CNS abnormalities, and HIV-associated myelopathy (HAM). The evidence supporting current concepts of viral neuropathogenesis will be presented in this context and then the impacts of efficacious combined antiretroviral therapy (cART). Finally, the emerging problem of CNS viral compartmentalization and unanswered questions about CNS reservoirs will be described.

HIV-associated CNS disorders remain prevalent, both in treated and untreated populations. While effective therapies shift the spectrum of disorders, they do not extirpate infection or nervous system abnormality. The long-term consequences of chronic persistent infection and immune dysregulation, coupled with emerging comorbidities, make understanding CNS neuropathogenesis of importance to any scientist or clinician encountering individuals infected with HIV. Until eradicating cures are achieved, CNS infection with HIV will remain a highly relevant topic for study and investigation.