At least 45% of American adults have been tested for HIV at least once, an increase of five percentage points and 11.4 million people since 2006, the Centers for Disease Control and Prevention said Tuesday. But that still leaves 55% of adults, and 28.3% of adults with risk factors for contracting HIV, who have never been tested, the agency said in a Vital Signs report. About 48% of women have been tested, but only 41% of men.
The CDC estimates that about 1.1 million Americans are HIV-positive and that about 200,000 of them do not know it because they have never been tested. More than 30% of those who do become diagnosed as HIV-positive do so only after they have been positive for several years, which makes controlling the infection much more difficult. A growing body of evidence also suggests that prolonged unrecognized infection also increases the risk of cardiovascular disease and other medical problems not directly related to AIDS. When people learn they are infected, they can also take steps to protect their sexual partners.