WASHINGTON More than one in four U.S. teen girls is infected with at least one sexually transmitted disease, and the rate is highest among blacks, the U.S. Centers for Disease Control and Prevention said on Tuesday.
An estimated 3.2 million U.S. girls ages 14 and 19 -- about 26 percent of that age group -- have a sexually transmitted infection such as the human papillomavirus or HPV, chlamydia, genital herpes or trichomoniasis, the CDC said.
Forty-eight percent of black teen-age girls were infected, compared to 20 percent of whites and 20 percent of Mexican American girls. The report did not give data on the broader U.S. Hispanic population.
"What we found is alarming," the CDC's Dr. Sara Forhan, who led the study, told reporters. "This means that far too many young women are at risk for the serious health effects of untreated STDs, including infertility and cervical cancer."
Dr. John Douglas, director of the CDC's Division of STD Prevention, said a complex mix of factors is to blame for the higher rates among black girls, including the overall higher presence of sexually transmitted diseases, or STDs, in the broader black community.
"Therefore, for any given sex act with any given partner, a person who's not infected has a greater risk of coming into contact with infection and getting infected," Douglas said.
The CDC said the rate of STD infection among U.S. teen girls might be higher than the study indicates because it did not look at syphilis, gonorrhea or HIV infection, but said these generally are uncommon in girls this age.
The CDC said the report, released at a meeting in Chicago, was the first to gauge combined rates of common STDs in female adolescents, giving the best data to date.
Among girls who had an STD, 15 percent had more than one. About half reported ever having had sex, and among those girls, 40 percent had at least one STD. Of girls who had just one lifetime sexual partner, 20 percent had at least one STD.
HPV, which can cause genital warts and cervical cancer, was the most common infection, seen in 18 percent of the girls. The CDC said this indicates teen girls, even those with few lifetime sexual partners, are at high risk for HPV infection.
CDC officials urge girls and women ages 11 to 26 who have not been vaccinated against HPV or who have not completed the full series of shots be fully vaccinated against the virus.
The next most common infection was chlamydia, caused by a bacterium that can damage a woman's reproductive organs. It was seen in 4 percent of the girls. Untreated infection can spread into the uterus or fallopian tubes and cause pelvic inflammatory disease. It also raises risk for infertility.
The CDC urges yearly chlamydia screening for sexually active women under age of 25.
Trichomoniasis, caused by a single-celled parasite, was seen in about 3 percent of the girls. Women with trichomoniasis have vaginal itching and discharge.
About 2 percent of girls were infected with herpes simplex virus type 2, which causes most cases of genital herpes.
The findings were based on data from 838 girls who took part in a nationally representative health survey in 2003 and 2004. They were tested for various STDs.
(Editing by Maggie Fox and Philip Barbara)