AIDS experts say more needs to be done to stop the spread of HIV among the group most susceptible.
WASHINGTON - Nearly half of high school students say they've had sex, but progress has stalled in getting them to use condoms to protect against the AIDS virus, government researchers reported Tuesday.
Today, four of every 10 new HIV infections occur in people younger than 30, according to the Centers for Disease Control and Prevention -- and the teen years, just as many youths become sexually active, are key for getting across the safe-sex message.
Using a longstanding survey of high school students' health, the CDC tracked how teen sexual behavior has changed over 20 years.
The results are decidedly mixed.
About 60 percent of sexually active high school students say they used condoms the last time they had sex, researchers said at the International AIDS Conference.
That's an increase from the 46 percent who were using condoms in 1991.
But it's down from the high of 63 percent reached in 2003.
Black students are most likely to heed the safe-sex message, but their condom use dropped from a high of 70 percent in 1999 to 65 percent last year, the study found.
The proportion of high school students who've had sex is 47 percent today -- down a bit from 54 percent in 1991 -- and they typically start at age 16, the CDC said.
Black teens showed a bigger decrease, with 60 percent sexually active today compared with 82 percent two decades ago.
The more partners, the more risk. Fifteen percent of high school students say they've had four or more partners, down from 19 percent in 1991.
Dr. Kevin Fenton, director of the CDC's HIV prevention center, said many school systems don't have strong enough sex education policies that include teaching teens about how to prevent HIV.
He cautioned that the CDC study can't link the abstinence-only policies pushed by Congress through the late 1990s and early 2000s to the stalled condom use.
Focusing on individual risk behaviors is just part of the story.
Increasingly, HIV is an infection of the poor, and specialists at the world's largest AIDS meeting are making the point all week at the conference that tackling the virus globally will require broader efforts to address problems of poverty.
Those include gaining better access to overall health services.