Quarter of U.S. teen girls have sex-related disease (Reuters)

WASHINGTON (Reuters) - More than one in four U.S. teengirls is infected with at least one sexually transmitteddisease, and the rate is highest among blacks, the U.S. Centersfor Disease Control and Prevention said on Tuesday.

An estimated 3.2 million U.S. girls ages 14 and 19 -- about26 percent of that age group -- have a sexually transmittedinfection 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 MexicanAmerican girls. The report did not give data on the broaderU.S. Hispanic population.

"What we found is alarming," the CDC's Dr. Sara Forhan, wholed the study, told reporters. "This means that far too manyyoung women are at risk for the serious health effects ofuntreated STDs, including infertility and cervical cancer."

Dr. John Douglas, director of the CDC's Division of STDPrevention, said a complex mix of factors is to blame for thehigher rates among black girls, including the overall higherpresence of sexually transmitted diseases, or STDs, in thebroader black community.

"Therefore, for any given sex act with any given partner, aperson who's not infected has a greater risk of coming intocontact with infection and getting infected," Douglas said.

The CDC said the rate of STD infection among U.S. teengirls might be higher than the study indicates because it didnot look at syphilis, gonorrhea or HIV infection, but saidthese 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 femaleadolescents, giving the best data to date.

MULTIPLE INFECTIONS

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 onelifetime sexual partner, 20 percent had at least one STD.

HPV, which can cause genital warts and cervical cancer, wasthe most common infection, seen in 18 percent of the girls. TheCDC said this indicates teen girls, even those with fewlifetime sexual partners, are at high risk for HPV infection.

CDC officials urge girls and women ages 11 to 26 who havenot been vaccinated against HPV or who have not completed thefull series of shots be fully vaccinated against the virus.

The next most common infection was chlamydia, caused by abacterium that can damage a woman's reproductive organs. It wasseen in 4 percent of the girls. Untreated infection can spreadinto the uterus or fallopian tubes and cause pelvicinflammatory disease. It also raises risk for infertility.

The CDC urges yearly chlamydia screening for sexuallyactive women under age of 25.

Trichomoniasis, caused by a single-celled parasite, wasseen in about 3 percent of the girls. Women with trichomoniasishave vaginal itching and discharge.

About 2 percent of girls were infected with herpes simplexvirus type 2, which causes most cases of genital herpes.

The findings were based on data from 838 girls who tookpart in a nationally representative health survey in 2003 and2004. They were tested for various STDs.