In August 2008, the Centers for Disease Control and Prevention (CDC) published an analysis showing that an estimated 56,300 new human immunodeficiency virus (HIV) infections occurred in 2006, a number that was significantly higher than the previous estimate of 40,000. This estimate highlights the importance of elucidating practice guidelines for the management of HIV infection that is still asymptomatic. According to an article published online April 1, 2009 in The New England Journal of Medicine, deferring HIV therapy increases the risk of death.

Investigators from the National Institutes of Health in Bethesda, Maryland and their colleagues performed two analyses on 17,517 asymptomatic patients with HIV infection in the United States and Canada who received medical care during the period from 1996 through 2005 in order to determine the optimal time for initiation of antiretroviral therapy. In the first analysis, which included 8,362 patients, 2,084 patients started therapy at a CD4+ count of 350 to 500 cells per cubic millimeter and 6,278 deferred therapy. The CD4+ count is a measure of how well the immune system is functioning, and as it falls, an individual's risk of infection increases. Among patients who deferred therapy, there was a 69% increased risk of death. In the second analysis, which included 9,155 patients, 2,220 initiated therapy at a CD4+ count of more than 500 cells per cubic millimeter and the remainder deferred therapy. Among those who deferred therapy in this analysis, there was a 94% increased risk of death.

Current guidelines recommend treatment for asymptomatic HIV patients when their CD4+ counts drop below 350 cells per cubic millimeter. The findings of this study suggests that these guidelines may need to be re-examined with randomized trials. However, the benefits of initiating antiretroviral therapy earlier after HIV infection still need to be weighed against the potential adverse effects of treatment.