Background: The percentage of individuals aged 50 and older among newly identified HIV cases is substantial and increasing over time in industrialized countries, while in Sub-Saharan Africa the vast majority of new infections still occurs among 15- to 49-year-olds. In the United States, 12.7% and 16.7% were males and females older than 50 in 2004, with most prominent increases in white women (2001: 10.5%; 2004: 15.3%). In western Europe, numbers were slightly lower—around 13% for males and 8% for females—while in eastern Europe only 2 to 3% of new infections occurred in older males and females in 2004. Nevertheless, the increasing proportion of older individuals among newly diagnosed HIV cases strongly calls for more prevention efforts targeted towards this population. A large cohort collaboration, focusing on patients with documented seroconversion, demonstrated that CD4 levels at seroconversion have an inverse relationship with age and that the subsequent CD4 decline and progression to AIDS in absence of ART are accelerated in older individuals. The spectrum of AIDS-defining conditions without ART does not seem to differ much across age groups. However, other potentially HIV-associated conditions are increasing with older age and the distinction between age-related and HIV-related conditions can be difficult (e.g., cognitive impairment). On ART, older patients appear to experience higher rates of liver and kidney disease than HIV-negative persons of the same age.

Conclusions: HIV screening should be scaled-up because older individuals are more likely to present for testing and care with lower CD4 cell counts and at more advanced stages of HIV infection than younger individuals. Multiple studies have shown that virological response to ART is better in all older age groups. In patients around 50 this also translates into a better immunologic recovery. With older age, however, CD4 cell count increases tend to weaken. Naturally, all-cause mortality is strongly associated with older age. Country- and gender-adjusted mortality ratios for HIV patients decrease towards one with older age as non-HIV mortality accounts for an increasingly larger proportion in the total mortality experienced.