Even more disturbing than the report that one in four teenage girls in the United States has sexually transmitted diseases is that only about half the girls acknowledged having sex. The findings from the Centers for Disease Control and Prevention are yet another indication that the emphasis on abstinence rather than honest talk about sexual activity and its consequences is failing.

According to the CDC, the STD rate among girls between the ages of 14 and 19 was 26 percent, which means that more than 3 million girls nationwide are infected. According to studies cited by the World Health Organization, the gonorrhea prevalence among teen girls in the United States is higher than in Chile, Thailand and Kenya.

“One of the reasons why young people are particularly vulnerable to sexually transmitted infections is the lack of sex education,” the WHO report said. “There is still reluctance in some quarters to acknowledge and properly address adolescent sexual activity despite widespread evidence of how early sex begins and the extent of unwanted pregnancies and sexually transmitted infections in young age groups.”

That reluctance comes at a heavy price as the CDC figures show. STDs include gonorrhea, genital herpes, chlamydia and human papillomavirus, or HPV. Chlamydia can damage reproductive organs and lead to infertility. HPV can cause cervical cancer and was the most commonly reported infection in the CDC study, which was the first to quantify total STD rates among teen girls. There is now a vaccine against HPV.

Despite these risks, many parents are hesitant to talk about sex and ways to prevent pregnancy and sexually transmitted diseases, and sex education remains controversial. A recent study found that 98 percent of parents thought their children were virgins. Yet a 2005 CDC study found that a quarter of 15-year-olds have had sexual intercourse. The percentages steadily increase and, at age 18, 62 percent of boys and 70 percent of girls have had sex. A study published in the Journal of the American Medical Association found that children exposed to contraception education were not more likely to have sex than those in abstinence-only programs but they were two-thirds less likely to have unprotected sex.

Growing numbers of teens, even those who have taken pledges of abstinence, are engaging in oral sex as an alternative to intercourse. Many perceive it as safer, but this is a false sense of security since STDs can also be spread through this type of contact.

Youths should be encouraged to abstain from sex. The reality is that many won’t, so ensuring they understand the real dangers and consequences of their sexual activity is crucial.