Researchers believe that as HIV has adapted to its hosts over time (as lowering CD4 counts in newly diagnosed HIV patients indicate) it may have become more virulent and dangerous.

The CDC recently changed guidelines regarding when to start drug therapy for HIV. More and more reasons are being discovered to start these therapies earlier and earlier...

In the United States in 2006, 56,300 new HIV infections occurred, according to CDC's first national estimate of HIV incidence based on direct measurement. The previous estimate of 40,000 new infections annually had been based on new diagnoses - data that were limited in that years could have elapsed between a patient's infection and diagnosis. The revised estimate is based on a new CDC- developed testing method that differentiates between infections acquired within about the previous five months and longstanding infections.