Despite stable rates of HIV diagnosis in older populations, the rate of HIV diagnoses from 2006 to 2009 increased in teens 15-19 and youth 20-24 years of age, and was highest in the 20-24 year-old age group.  Undiagnosed HIV cases are also thought to be highest among young people. The U.S. Centers for Disease Control and Prevention (CDC) estimates more than half of all undiagnosed HIV infections are youth ages 13 – 24.3.

Of adolescent HIV diagnoses, almost 70 percent are to black teens, even though they constitute a much smaller proportion of the adolescent population in the U.S.    Almost 80 percent of all adolescent infections are to males. Nine out of 10 adolescent male HIV infections result from male-to-male sexual contact. The same proportion of adolescent females is infected from heterosexual contact.

The highest concentrations of HIV diagnoses among adolescents are in the Southeastern United States and, specifically, Florida, South Carolina, and Louisiana.
Although HIV testing is widely available, self-reported rates of HIV testing have remained flat in recent years. Forty-six percent of high school students have had sex at least once, yet only 13 percent report ever having had an HIV test.