Taken before AIDS develops, HIV drugs prolong life and health. People who know they have HIV are less likely to transmit the virus than are people who are infected but don't know it. And 28% of Americans most at risk of HIV infection have never been tested, the CDC today reported. HIV testing is the cornerstone of the CDC's HIV/AIDS prevention program. African Americans get more than half of new HIV infections in the U.S., yet only 60% have ever been tested. In 2009, 55% of Americans aged 18 64 82.9 million people have had at least one HIV test.

People being treated for their HIV infection are less likely to transmit the virus to others.

Men who have sex with men make up more than 55% of people with HIV, yet only 40% of these at risk men were tested in the past year. Nearly one in three people who test positive for HIV have waited too late. Most HIV infections come from people who. "Progress is being made, but this shows how much more progress is needed," CDC Director Orren R.

Frieden, MD, MPH, said at a news teleconference.