A recent report from the Center for Disease Control and Prevention revealed that one in four teenage girls in the United States has a sexually transmitted disease (STD) and nearly half of young African-American women are infected.

"The report was no surprise," said Jane Tuitt, a nurse practitioner at Dorchester High School. Around 90 percent of the students she treats are African-American, Tuitt said.

"We've known for years that this population is at high risk. We see it," said Tuitt.

"The data confirms what we already knew," said Dr. Lydia Shrier, a researcher at Children's Hospital Boston. "Adolescent women are at an extremely high risk of STDs," she said, "and the racial differences are the most disturbing part."

According to the 2007 Health of Boston Report from the Boston Public Health Commission, nearly a third of reported cases of chlamydia in Boston in 2005 were found in 15 to 19-year-olds and the rate of chlamydia among African-Americans in Boston was more than eight times higher than that of whites.

The report also shows disproportionate rates of new cases of chlamydia reported in Dorchester and Mattapan in 2005; the rates were more than 50 percent higher than that of Boston overall. According to the 2000 census, 45 percent of Dorchester residents and 83 percent of Mattapan residents are African-American.

"It's a big issue in Dorchester health centers," said Bill Walczak, director of Codman Square Health Center. "Doctors are very, very concerned."

"The numbers are alarming," said Dr. Ethan Brackett, a family practitioner at Codman Square Health Center. Brackett said he believes the national numbers are representative of STD prevalence rates in Dorchester, pointing to "a difficult problem within the community."

"It's a very complex and charged issue," Shrier said, attributing racial disparities in the STD epidemic to issues including, but not limited to, access to healthcare, poverty rates, and neighborhood context.

"Race is a proxy for a number of other things and it's not just [socio-economic status]," Shrier said. There are also marked cultural differences in partnering, she said, noting that young African-American women are more likely to have older partners, "introducing infection from a sexually experienced group of men…The frequency of partner change and the different pools of partners in areas that are predominantly black" also contribute to racial differences, she said.

"It's an issue of access, an issue of awareness and an issue of shame," said Brackett, who notices a reticence in his patients to seek medical care. Differences in religious beliefs and family dynamics among African-Americans - particularly immigrants - he said, make it difficult to discuss sex and intimate issues.

"Many patients come to me as almost a last resort," Brackett said. "They have to reach a tipping point of concern or symptom before engaging with the medical community," at which point they may have already spread the infection to others.

Shrier said researchers were excited about the CDC report and the attention it could bring to the STD epidemic. It was compiled from the 2003-2004 National Health and Nutrition Examination Survey, which screened 838 randomly selected girls, ages 14-19, for four common STDs: human papillomavirus (HPV), chlamydia, genital herpes, and trichomoniasis, a parasite. The data says, "Look, this is the burden of these common infections in this age group," Shrier said.

The report, which was presented on March 11 at the 2008 National STD Prevention Conference in Chicago, included STDs that are not routinely screened for, Shrier said.

"We've been studying gonorrhea and HIV, which cluster more in poor urban areas where drug use is a major issue," Shrier said, "but this report cuts across a lot of those lines. We see that HPV is everywhere."

Found in 18 percent of the young women screened, HPV is the most common STD, causing cervical cancer and genital warts. There is a vaccine available which protects against four types of HPV that cause 70 percent of cervical cancer cases and 90 percent of genital warts, though Shrier said a mandatory vaccine for adolescent girls has been a hard case to make.

"It's been a community-by-community debate across the country," Shrier said, "This will protect the individual and if enough people get vaccinated it will become a herd immunity…But it's different than going to school with the measles." Nationwide, legislators and others are reluctant to mandate comprehensive sex education, let alone STD vaccinations, Shrier said.

Brackett said the report should be "a lesson to all of us that we need to be even more serious about prevention programs, talking to teenagers about sex, being honest with them, and starting conversations about sexual activity early." The current plan of attack, he said--teaching abstinence only, or starting sex education in the fifth grade - is not enough.

Bracket also hopes that this will be "a wake up call for us to reach out to young men in the community," who are "vectors for many of these STDs," though they are less likely to present symptoms or seek care. Instead, they contribute to the epidemic among females who bear the burden of infections and suffer more serious consequences such as infertility, cervical cancer, or ectopic pregnancies, Shrier said.

At Dorchester High School, Tuitt said she actively tries to reach as many students that are sexually active as she can, reminding them that STD screening is as simple as a urine test. She suggests screening to anyone that comes to her office for contraceptives or Plan-B, the morning after pill, and said that many students don't realize they are even at risk for STDs as teenagers. "The adults that work with adolescents weren't surprised" by the high rates of STDs reported in adolescents, Tuitt said, but "the info hasn't filtered down to the kids yet and we need to push that more."