Natural History and Classification

Classification of the natural history of untreated HIV infection into discrete disease stages helped to optimize the treatment approach to those infected with HIV. Due to the advancements in antiretroviral treatment and current treatment recommendations some of the subdivisions of chronic HIV infection are now seemingly more of historical than clinical value, but the clinically important stages are discussed in further detail in this chapter. It is important to note that although antiretroviral therapy has completely changed the disease course of HIV and altered the relevance of some of the disease stages there remains a gap in the life expectancy of treated HIV-infected individuals compared to uninfected controls in the general population. This chapter defines the various stages of HIV, beginning with primary HIV infection before moving onto chronic HIV infection and its complications. The diagnosis and staging of HIV is also discussed in detail, allowing it to be looked at from both clinical and research perspectives.