At least one in four teen girls in the US—that's over three million people—has a sexually transmitted disease, a new CDC study shows. By far the most common infection is the human papillomavirus, which can cause cervical cancer, the AP reports. An STD expert calls the new figures "clear signs that we must continue developing ways to reach those most at risk."
"You're talking about nearly half of the sexually experienced teens at any one time having evidence of an STD," said a pediatric medicine expert. Black teens had the highest infection rate; almost 50% had an STD. Some experts say screenings for STDs are underused because of docs who think "sexually transmitted diseases don't happen to the kinds of patients I see," says a CDC official. (Read more STD stories.)