American squeamishness about talking about sex has helped keep common sexually transmitted infections far too common, especially among vulnerable teens, U.S. researchers reported Monday.

Latest statistics on chlamydia, gonorrhea and syphilis show the three highly treatable infections continue to spread in the United States.

Chlamydia and gonorrhea are stable at unacceptably high levels and syphilis is resurgent after almost being eliminated, said John Douglas, director of the division of sexually transmitted diseases at the U.S. Centers for Disease Control and Prevention.

We have among the highest rates of STDs of any developed country in the world, Douglas added in a telephone interview.

The administration of President Barack Obama has signaled a willingness to move away from so-called abstinence-only sex education approaches promoted by his predecessor, George W. Bush, and conservative state and local governments.

Several studies have shown such approaches do not work well and that it is better to encourage abstinence while also offering children and teens information about how t

o protect themselves from diseases as well as pregnancy.

We haven't been promoting the full battery of messages, Douglas said. We have been sending people out with one seatbelt in the whole car.

SOARING RATES

The CDC's latest study on STDs found:

* 1.2 million cases of chlamydia were reported in 2008, up from 1.1 million in 2007.

* Nearly 337,000 cases of gonorrhea were reported.

* Adolescent girls 15 to 19 years had the most chlamydia and gonorrhea cases of any age group at 409,531.

* Blacks, who represent 12 percent of the U.S. population, accounted for about 71 percent of reported gonorrhea cases and almost half of all chlamydia and syphilis cases in 2008.

* Black women 15 to 19 had the highest rates of chlamydia and gonorrhea.

* 13,500 syphilis cases were reported in 2008, an almost 18 percent increase from 2007.

* 63 percent of syphilis cases were among men who have sex with men.

* Syphilis rates among women increased 36 percent from 2007 to 2008.

Syphilis, chlamydia and gonorrhea can all be treated with antibiotics but untreated can cause pelvic inflammatory disease, infertility, ectopic pregnancy and can infect newborns.

Douglas said better sex education can help.

We are not honestly and openly dealing with this issue and it's the larger issue of sexual health, he said.

Douglas said children and teens need to know about condom use, and should limit their number of sex partners and avoid sex with people who do have many other sex partners.

If you are a man who has sex with men you ought to be getting a battery of STD tests every year, Douglas added.

In addition, black Americans need to understand their risks. Douglas said high rates of incarceration of men in many black communities meant fewer men have sex with more women, in turn often spreading sexually transmitted diseases.

Overall, CDC estimates that 19 million new sexually transmitted infections occur each year, almost half among 15- to 24-year-olds.