June 26, 2009 -- About 50,000 adolescents and young adults aged 13 to 24 were living with the virus that causes AIDS in 2006, but nearly half of them didn't know they were HIV infected, according to the CDC.
The CDC says in its June 26 Morbidity and Mortality Weekly Report that young adults represented 4.4% of the 1.1 million people living with the human immunodeficiency virus in 2006.
That would amount to 48,400 young people with HIV.
The CDC says that 232,700 people in the U.S. were living with HIV that year and didn't know it. Adolescents and young adults represented 9.9% of that number, or some 23,000 youths.
Early diagnosis of HIV infection is critical because detection speeds up medical intervention and informs people with the virus to reduce high-risk behaviors that could spread infections, the CDC says.
The CDC says it used adolescent data from the 2007 Youth Risk Behavior Survey.
The results indicated that nationwide 12.9% of all high school students had been tested for HIV at some point in their lives.
The prevalence rate of HIV testing increased with grade and age.
Prevalence of HIV testing decreased with older age of first sexual intercourse experience, the report says.
Among female students, 14.8% had been tested for HIV, compared to 11.1% of males. The prevalence rate also was higher among non-Hispanic black students at 22.4% than for non-Hispanic whites at 10.7%.
The CDC recommends routine HIV screening for all people 13-64 years old to decrease the number of undiagnosed infections and the spread of new infections.
"HIV testing among sexually active adolescents is an important strategy to reduce the incidence of HIV infection," the CDC says. "Because adolescents might be sexually active but unwilling to discuss this information, health care providers should provide HIV screening routinely to all patients aged 13 and older."
The Youth Risk Behavior Survey estimates the prevalence of health risk behaviors among high school students. The 2007 national survey examined data from more than 14,000 anonymous questionnaires completed by public and private high school students in the 50 states and Washington, D.C.