Who Has HIV? 55% in U.S. Don't Know

Nov. 30, 2010 -- More U.S. adults than ever before report getting at least one HIV test -- but 55% of Americans don't know for sure whether they carry the AIDS virus.

And 28% of Americans most at risk of HIV infection have never been tested, the CDC today reported.

"Progress is being made, but this shows how much more progress is needed," CDC Director Thomas R. Frieden, MD, MPH, said at a news teleconference.

According to a new CDC report:

• In 2009, 55% of Americans aged 18-64 -- 82.9 million people -- have had at least one HIV test.
• Nearly one in three people who test positive for HIV have waited too late: They already have AIDS.
• African-Americans get more than half of new HIV infections in the U.S., yet only 60% have ever been tested.
• 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.

HIV testing is the cornerstone of the CDC's HIV/AIDS prevention program. Why?

• People who know they have HIV are less likely to transmit the virus than are people who are infected but don't know it.
• Taken before AIDS develops, HIV drugs prolong life and health.
• People being treated for their HIV infection are less likely to transmit the virus to others.
• Most HIV infections come from people who don't know they carry the virus.

At least 200,000 Americans have HIV and don't know it. Many only find out when they develop AIDS.

"Virtually all AIDS cases are preventable, either by preventing infection or by early treatment," Frieden said. "However, 37,000 Americans were diagnosed with AIDS in 2008."

In 2006, the CDC recommended that all Americans get routine HIV tests. Those at high risk of infection should get tested at least once a year, if not more often.

"Forty-four percent of men found to be infected with HIV did not know they were infected, yet half were tested in the past year," Jonathan Mermin, MD, MPH, director of the CDC's HIV/AIDS prevention program, said at the news conference. "This confirms the importance of more frequent testing for those at high risk."

Frieden stressed the importance of making HIV tests routine. He noted that about 70% of people diagnosed with HIV only when they had AIDS had received medical care but were not tested.

"It is not as if these are people there is no hope of reaching," he said. "This is why the CDC recommends routine, voluntary screening for HIV in health care facilities, so even if a person does not indicate an HIV risk factor, we say, 'We test everyone, and we think you should get a test.'"

The CDC report comes in the Nov. 30 "Vital Signs" special issue of Morbidity and Mortality Weekly Report.