CHICAGO -- At least one in four teenage girls nationwide has a sexually transmitted disease, or more than 3 million teens, according to the first study of its kind in this age group.
A virus that causes cervical cancer is by far the most common sexually transmitted infection in teen girls aged 14 to 19, while the highest overall prevalence is among black girls — nearly half the blacks studied had at least one STD. That rate compared with 20 percent among both whites and Mexican-American teens, the study from the federal Centers for Disease Control and Prevention found. Among girls who admitted ever having sex, the rate was 40 percent. While some teens define sex as only intercourse, other types of intimate behavior including oral sex can spread some infections. For many, the numbers likely seem "overwhelming because you're talking about nearly half of the sexually experienced teens at any one time having evidence of an STD," said Dr. Margaret Blythe, an adolescent medicine specialist at Indiana University School of Medicine and head of the American Academy of Pediatrics' committee on adolescence. But the study highlights what many doctors who treat teens see every day, Blythe said. Dr. John Douglas, director of the CDC's division of STD prevention, said the results are the first to examine the combined national prevalence of common sexually transmitted diseases among adolescent girls. He said they likely reflect current prevalence rates. "High STD rates among young women, particularly African-American young women, are clear signs that we must continue developing ways to reach those most at risk," Douglas said. The CDC's Dr. Kevin Fenton said given that STDs can cause infertility and cervical cancer in women, "screening, vaccination and other prevention strategies for sexually active women are among our highest public health priorities." The study by CDC researcher Dr.