Health officials say 1 in 5 new HIV infections occur in a tiny segment of the population -- young men who are gay or bisexual.
The government released new numbers Tuesday that spotlight how the spread of the AIDS virus is heavily concentrated in young males who have sex with other males. Only about a quarter of new infections in the 13-to-24 age group are from injecting drugs or heterosexual sex.
The Centers for Disease Control and Prevention said blacks represented more than half of new infections in youths. The estimates are based on 2010 figures.
Overall, new U.S. HIV infections have held steady at around 50,000 a year. About 12,000 are in teens and young adults, and most youth with HIV haven't been tested.
More than half of young people infected with HIV are not aware of it, according to the report. And those ages 13 to 24 account for 26 percent of all new HIV infections.
"Given everything we know about HIV and how to prevent it in 30 years of fighting the disease, it's just unacceptable that young people are becoming infected at such high rates," CDC Director Dr. Thomas Frieden told reporters.
-- AP, with Reuters