Teenage pregnancies and syphilis have risen sharply among a generation of American school girls who were urged to avoid sex before marriage under George Bush's evangelically-driven education policy, according to a new report by the US's major public health body.

In a report that will surprise few of Bush's critics on the issue, the Centres for Disease Control says years of falling rates of teenage pregnancies and sexually transmitted disease infections under previous administrations were reversed or stalled in the Bush years. According to the CDC, birth rates among teenagers aged 15 or older had been in decline since 1991 but are up sharply in more than half of American states since 2005. The study also revealed that the number of teenage females with syphilis has risen by nearly half after a significant decrease while a two-decade fall in the gonorrhea infection rate is being reversed. The number of Aids cases in adolescent boys has nearly doubled.

The CDC says that southern states, where there is often the greatest emphasis on abstinence and religion, tend to have the highest rates of teenage pregnancy and STDs.

In addition, about 16,000 pregnancies were reported among 10- to 14-year-old girls in 2004 and a similar number of young people in the age group reported having a sexually transmitted disease.

"It is disheartening that after years of improvement with respect to teen pregnancy and sexually transmitted diseases, we now see signs that progress is stalling and many of these trends are going in the wrong direction," said Janet Collins, a CDC director.

Although the CDC does not attribute a cause, groups that support comprehensive sex education have seized on the report as evidence of the failure of religiously-driven policies that shy away from teaching about contraception in favour of emphasising avoiding sexual contact.

Planned Parenthood said the CDC report is "alarming" and confirms that teenagers need "medically accurate, age-appropriate, comprehensive sex education".

But supporters of abstinence-based education said that the new report shows that there is too little not too much emphasis on discouraging sex before marriage.

Kristi Hamrick, a spokeswoman for American Values, which describes itself as a supporter of traditional marriage and "against liberal education and cultural forces", said the abstinence message is overwhelmed by a culture obsessed with sex.

"It is ridiculous to say that a programme we nominally invest in has failed when it fails to overcome the most sexualised culture in world history. Education that emphasises abstinence as the best option for teens makes up a minuscule part of overall sex education in the United States," she said.

"In every other area of public policy - food, drugs, alcohol - we tell children what is the best choice. It seems very bizarre that the sex education establishment rejects the idea that we should talk to kids about what is best for them. We don't take vodka to drivers education because children will drink and drive."