It is now more than a quarter century since the appearance of the f irst reported cases of the acquired immunodeficiency syndrome (AIDS). Although successful tre- ments with highly active antiretroviral therapies have made a major impact on survival, there still remains no vaccine for prevention and the available therapies do not cure the disease. As a result, AIDS has been transformed into a chronic, lifelong disease which requires continuous antiretro viral drug treatment together with ongoing treatment of the associated systemic medical complications. It appears that as survival improves,...