THURSDAY, April 5 (HealthDay News) -- There's been little progress in recent years in boosting the number of American secondary schools that teach students how to prevent pregnancy and protect themselves against HIV and other sexually transmitted diseases (STDs).

That's the finding from researchers at the U.S. Centers for Disease Control and Prevention who analyzed 2008 and 2010 data from 45 states taking part in biennial surveys of school health practices.

The surveys assessed the percentage of schools in each state that teach specific topics related to HIV, STD and pregnancy prevention. The topics differ in middle schools and high schools, but generally include basic information on the transmission and diagnosis of HIV and other STDs, as well as pregnancy risk reduction. Condom use is one of the topics that's covered only in high schools, the CDC said.

The surveys revealed few indications of progress between 2008 and 2010. For example, the percentage of middle schools that taught all essential topics to grades 6, 7 and 8 declined in 11 states and did not rise in any of the other 33 states.

In high schools, the percentage that taught all eight essential topics to grades 9, 10, 11 and 12 declined in one state and increased in two states. And the percentage of high schools that taught three condom-related topics fell in eight states while increasing in only three.

Broken out by states in 2010, the report showed that the percentage of middle schools that taught all topics ranged from 12.6 percent in Arizona to 66.3 percent in New York. The percentage of high schools that taught all topics ranged from 45.3 percent in Alaska to 96.4 percent in New Jersey. And the percentage of high schools that taught all three condom-related topics ranged from 11.3 percent in Utah to 93.1 percent in Delaware.

Education on avoiding infection with HIV and other STDs is critical, especially for children in middle schools who most likely have not begun sexual activity, experts said in an editorial accompanying the new study.

"HIV prevention can also address misperceptions about how HIV is transmitted," they noted. For example, they say, one poll conducted in 2011 found that "20 percent of persons aged 18-29 believe incorrectly that a person can become infected with HIV by sharing a drinking glass, or are unsure of whether this statement is true or false."

Schools remain integral to educating young people about ways they can keep themselves and others safe, the experts added.

"Families, the media, and community organizations, including faith-based organizations, can play a role in providing HIV, other STD, and pregnancy prevention education," the editorialists pointed out. "However, schools are in a unique position to provide [this education] ... because almost all school-aged youths in the United States attend school."

The study appears in the April 6 issue of Morbidity and Mortality Weekly Report, published by the CDC.

More information

The American Academy of Pediatrics has more about teen sexuality.