U.S. teens are getting sex education, but most are not learning about birth control from their parents, new government data showed on Thursday.

And rates of infection with sexually transmitted diseases reflect this -- the annual rate of AIDS diagnoses for boys aged 15 to 19 years has nearly doubled in the past 10 years.

The numbers show that U.S. youth need better sex education, the U.S. Centers for Disease Control and Prevention said.

The new administration of President Barack Obama has been dropping some of the more controversial policies of the former Bush government, including an emphasis on abstinence-only education.

"The data presented in this report indicate that many young persons in the United States engage in sexual risk behavior and experience negative reproductive health outcomes," the CDC wrote in its weekly report on death and disease.

For its report, the CDC compiled data from many different studies of hundreds of thousands of children and young adults aged 10 to 25.

Among 18 and 19-year-olds, 49.8 percent of girls and just 35 percent of boys had talked with a parent about methods of birth control.

More than 80 percent of boys and girls said they had received formal instruction before age 18 on how to say no to sex.

Nearly 70 percent of teen girls and 66 percent of boys had received instruction on methods of birth control.

Thirty percent of girls aged 15 to 17 reported they had engaged in sex; this rose to 70.6 of girls aged 18 to 19.

For boys, 31.6 of those aged 15 to 17 had ever had sex; 64.7 percent of those aged 18 to 19.

Nearly 10 percent of young women aged 18 to 24 said their first intercourse was involuntary.

Infections with the human immune deficiency virus that causes AIDS rose among boys aged 15 to 19 from 1.3 cases per 100,000 in 1997 to 2.5 cases in 2006.

(Agencies)