The 2008 HIV infection case definition for adults and
adolescents (aged >13 years) replaces the HIV infection and
AIDS case definitions and the HIV infection classification system (1–3,5). The case definition is intended for public health
surveillance only and not as a guide for clinical diagnosis. The
definition applies to all HIV variants (e.g., HIV-1 or HIV-2)
and excludes confirmation of HIV infection through diagnosis
of AIDS-defining conditions alone. For surveillance purposes, a
reportable case of HIV infection among adults and adolescents
aged >13 years is categorized by increasing severity as stage 1,
stage 2, or stage 3 (AIDS) or as stage unknown (Table).