2008 STD Prevention Conference - Summaries of Highlighted Research, 11 March 2008

Prevalence of Sexually Transmitted Infections and Bacterial Vaginosis among Female Adolescents in the United States: Data from the National Health and Nutritional Examination Survey (NHANES) 2003-2004; Oral Session, Thursday, March 13, 8:30 am Central [Oral Abstract D4a – Embargo: Tuesday, March 11, 11:30 am Central (12:30 pm ET)]

Integration of Contraceptive and STD/HIV Services for Young Women in the United States; Poster Session, Tuesday, March 11, 5:00 pm Central [Poster Abstract P125 – Embargo: Tuesday, March 11, 11:30 am Central (12:30 pm ET)]

STD Testing at Emergency Contraception Visits, New York City STD Clinics, 2005-2007;
Oral Session, Tuesday, March 11, 3:00 pm Central [Oral Abstract B9c – Embargo: Tuesday, March 11, 11:30 am Central (12:30 pm ET)]

To Screen or Not to Screen – Maximizing Chlamydia Screening of Adolescent Females in
School Based Health Centers in California
; Oral Session, Tuesday, March 11, 3:00 pm Central [Oral Abstract B8c – Embargo: Tuesday, March 11, 11:30 am Central (12:30 pm ET)]

The Impact of Introducing ″Express Visits″ for Asymptomatic Persons Seeking STD Services in a Busy Urban STD Clinic System, New York City, 2005-2006; Oral Session, Wednesday, March 12, 10:15 am Central [Oral Abstract C2d – Embargo: Tuesday, March 11, 11:30 am Central (12:30 pm ET)]

Oral Abstract D4a – Prevalence of Sexually Transmitted Infections and Bacterial Vaginosis among Female Adolescents in the United States: Data from the National Health and Nutritional Examination Survey (NHANES) 2003-2004

One in Four Female Adolescents Is Infected with At Least One Sexually Transmitted Infection, New CDC Study Finds

A new CDC study indicates that one in four (26%) female adolescents in the United States has at least one of the most common sexually transmitted infections (STIs). Led by CDC’s Sara Forhan, the study is the first to examine the combined national prevalence of common STIs among adolescent women in the United States.

The authors analyzed data on 838 female adolescents (aged 14-19) who participated in the 2003-2004 National Health and Nutrition Examination Survey (NHANES), a continuous annual study that examines a nationally representative sample of the U.S. household population to assess a broad range of health issues. For this analysis, the teens were tested for human papillomavirus (HPV) infection, chlamydia, herpes simplex virus type 2 (HSV-2) infection, and trichomoniasis. The authors examined high-risk HPV types, including 23 types of the virus that
are known to cause cancer, and the two types that cause most genital warts.

Based on the overall STI prevalence of 26 percent, the authors estimate that about 3.2 million adolescent females in the United States are infected with one of these STIs. They note that the total prevalence might be slightly higher than these estimates indicate, because some STIs – including syphilis, HIV and gonorrhea – were not included in the analysis; however, the prevalence of these STIs is low in this age group.

In addition to overall STI prevalence, key findings of the new study include the following:

  • The most common STI was cancer- and genital wart-associated HPV (18.3%), followed by chlamydia (3.9%), trichomoniasis (2.5%), and HSV-2 (1.9%). Among the teenage girls who had an STI, 15 percent had more than one.
  • By race, African American teenage girls had the highest prevalence, with an overall STI prevalence of 48 percent compared to 20 percent among both whites and Mexican Americans. (Other Hispanics and race/ethnic populations were captured in the survey, but there were insufficient numbers in any one group to permit valid prevalence estimates for any group except Mexican Americans.)
  • Overall, approximately half of all the teens in the study reported ever having had sex. Among these girls, the STI prevalence was 40 percent.
  • Even among girls reporting only one lifetime partner, one in five (20.4%) had at least one STI. Girls with three or more partners had a prevalence of over 50 percent. The predominant STI was HPV.

According to the authors, the high prevalence of HPV indicates that teenage girls are at high risk for this infection, even those with few lifetime sexual partners. It is important to realize that most HPV infections clear on their own; however some infections persist over time, placing women at risk for cervical cancer. A vaccine against HPV types 16 and 18, responsible for 70 percent of cervical cancer, and types 6 and 11, responsible for nearly all genital warts, is now recommended routinely for 11 and 12 year-old girls.

These data also underscore the importance of chlamydia screening to ensure prompt diagnosis and treatment, and to avoid the serious long-term consequences of the disease, which include pelvic inflammatory disease (PID) and infertility. CDC recommends annual chlamydia screening of all sexually active women aged 25 and under.

CDC supports a comprehensive approach to STD prevention that includes the promotion of abstinence as the surest way to prevent getting an STD, being in a mutually monogamous relationship with a partner known to be uninfected, and the consistent and correct use of condoms for sexually active people to reduce the risk of acquiring many infections. Condoms (used all the time and the right way) may lower your chances of passing HPV to a partner or developing HPV-related diseases.

Poster Abstract P125 – Integration of Contraceptive and STD/HIV Services for Young Women in the United States

Nationally Representative Study Reveals Missed HIV and STD Screening Opportunities for Young, High-Risk Women Seeking Contraceptive Services

A nationally representative study of contraceptive and STD/HIV services received by sexually active young women in the United States indicates that the majority receive either contraceptive services or STD/HIV services, but few receive both. The study also reveals that in a subset of young women at highest risk for STD/HIV infection, many are receiving contraceptive services but are not being screened for STDs or HIV.

Led by Sherry Farr, CDC researchers examined data from the 2002 National Survey of Family Growth, a national survey of adults aged 15-44. In the study, Farr and colleagues analyzed data on a subset of 1,328 unmarried, sexually active young women aged 15-24. The survey asked these young women about the contraceptive and STD/HIV services (counseling, testing, or treatment) they had received during the previous year. Researchers weighted the data to estimate the national prevalence of young women who received such services in the United

The study found that 82 percent of women in the U.S. received either contraceptive or STD/HIV services, but only 39 percent received both. Younger women (aged 15-22) were more likely to receive both types of services (41%) than women aged 23-24 (32%). Overall, women were almost twice as likely to receive contraceptive services as STD/HIV services (79% vs. 42%). Almost one in five sexually active women (18%) received neither contraceptive nor STD/HIV services.

Of the 38 percent of women who reported receiving contraceptive services associated with having unprotected sex (e.g., pregnancy testing or a prescription for emergency contraception), only slightly more than one-third of them (38%) received STD/HIV services. This suggests that the majority of young women most in need of STD/HIV counseling, testing, or treatment are not being reached with necessary services.

According to the study, women accessed about half (51%) of all STD and contraceptive services at doctors’ offices, 20 percent at community clinics, and 16 percent at family planning clinics.

Farr and colleagues note that the study underscores the urgent need for greater integration of contraceptive and STD/HIV services in order to expand STD/HIV prevention opportunities among all sexually active young women seeking reproductive or other sexual health services.

Oral Abstract B9c – STD Testing at Emergency Contraception Visits, New York City STD Clinics, 2005–2007

Study Shows Few Women Seeking Emergency Contraception are Tested for STDs Despite Being at High Risk

Women requesting emergency contraception (EC) at STD clinics are considered to be at high risk for STDs because they typically report recent unprotected sex. Yet new research conducted at the ten STD clinics run by the New York City Department of Health and Mental Hygiene (NYC DOHMH) shows that only about one in four of these women was screened for two of the most common STDs – chlamydia and gonorrhea – at the time of their request for EC. Among those who were screened for chlamydia and gonorrhea, more than one in ten was infected, suggesting that EC-related visits present an important opportunity to increase detection and treatment of STDs.

Emergency contraception is requested at one in every 17 visits by women to New York City STD clinics. Although EC is available for over-the-counter sale in New York to women who are 18 and older, the clinics provide EC at no cost and are an important resource for young and lowincome women in need of EC.

To assess STD testing rates among women seeking emergency contraception, the researchers analyzed electronic medical records from visits to the city’s STD clinics between October 2005 and April 2007. They identified 4,657 visits at which EC was requested. The majority (77%) of these EC-request visits were by young women aged 13-25; the median age was 21 (range: 13- 49).

Chlamydia and gonorrhea testing was performed at only 27 percent (1,259/4,657) of all ECrequest visits. Among the women who were tested for these STDs, investigators found that 12 percent of patients (149/1,259) tested positive for one or both infections. Specifically, 11 percent tested positive for chlamydia and 2 percent tested positive for gonorrhea. Women aged 25 and younger had much higher combined chlamydia and gonorrhea positivity (14%) than women over age 25 (7%), a finding that is consistent with surveillance data showing that gonorrhea and chlamydia case rates are highest among women under age 25.

As a result of this analysis, in October 2007 the New York City STD clinics began actively encouraging all women who seek emergency contraception to get tested for chlamydia and gonorrhea. Researchers believed this approach would identify many previously undetected STD infections and help young women avert the potentially serious complications of untreated chlamydia and gonorrhea, including pelvic inflammatory disease and infertility. The researchers measured chlamydia and gonorrhea screening at EC-request visits during November 2007
through January 2008, and found that among visits where EC was requested, the proportion at which testing was done increased to 57 percent (419/734). The positivity rate remained high at 10 percent (42/419). This suggests that actively offering chlamydia and gonorrhea screening to women when they come to STD clinics for EC could reach at-risk women who might not otherwise be tested, and improve disease detection and treatment. The researchers plan to continue to evaluate the impact of STD testing at EC visits in the future.

Oral Abstract B8c – To Screen or Not to Screen – Maximizing Chlamydia Screening of Adolescent Females in School Based Health Centers in California

CDC-Funded California Program Achieves High Rates of Chlamydia Screening in High School Health Centers; Highest Infection Rates Found Among African American Teens

Previous studies have shown that young women aged 15 to 19 have the highest rates of chlamydia infection in the country, and CDC recommends that all sexually active women age 25 and under be screened for chlamydia every year (and more frequently if they are at high risk for infection).

A new study led by Rebecca Braun of the California Family Health Council examined the effectiveness of a chlamydia screening program in California high school-based health centers (SBHCs). The researchers analyzed data from the CDC-funded Educational Partnerships to Increase Chlamydia Screening (EPICS) program at seven SBHCs in rural and urban California. The program provides funding, training, and technical assistance to encourage greater chlamydia screening among at-risk teens.

The researchers examined data from 1,321 sexually active adolescent girls who attended the SBHCs seeking contraceptive or STD services between July 2006 and June 2007.

Overall, almost nine in 10 teens (89.7%) attending the health centers were screened, and chlamydia was diagnosed in 6.5 percent of those screened. This positivity rate is more than double the U.S. Department of Health and Human Services’ Healthy People 2010 goal of three percent positivity for adolescents and young adults. Young black women (94.1%) and women identifying as “other race” (93.3%) were more likely to be screened than young white women (84.6%). In addition, young black women, Asian women, and women identifying as “other race” were more likely to test positive for chlamydia (9.6%, 6.5%, and 7.5%, respectively) than white women (1.7%). Older adolescents were also more likely to test positive for chlamydia: teens aged 13 to 14 had lower infection rates (3.2%) than those aged 15 to 17 years (6.0%), and those aged 17 to 19 years (6.4%).

The researchers are optimistic that the data will help California health officials focus screening and risk-reduction counseling on those most at risk, especially young African American women and older adolescents. Given the success of this program in reaching at-risk teens, the researchers also recommend that other states consider implementing confidential school-based chlamydia testing and treatment programs as a part of providing comprehensive reproductive health care services to adolescents.

Oral Abstract C2d – The Impact of Introducing “Express Visits” for Asymptomatic Persons Seeking STD Services in a Busy Urban STD Clinic System, New York City, 2005- 2006

“Express Visit” Option Leads to Significantly Increased STD Testing and Treatment at New York City Clinics

In response to increasing patient demand for STD screening and limited physician resources, the New York City Department of Health and Mental Hygiene (NYC DOHMH) made an “Express Visit” option a routine part of care at 10 STD clinics in 2006. With Express Visits, individuals who have no symptoms and report no known exposure to an STD can choose to be screened for STDs without having to be examined by a physician – though a medical examination is available to any patient who requests it. Prior to the introduction of Express Visits, individuals seeking STD testing at these clinics had no option other than being examined by a doctor.

In a study led by Jessica Borrelli and colleagues at the NYC DOHMH, researchers found that the Express Visit option significantly increased the number of patients who were tested for STDs and identified a greater number of STD cases, while still allowing clinics to treat the same proportion of infected individuals within 30 days of screening.

Borrelli and colleagues analyzed electronic medical records of patients visiting the 10 STD clinics operated by the NYC DOHMH during two comparable time periods – September- December 2005 (prior to routine availability of Express Visits) and September-December 2006. Individuals participating in Express Visits were screened for gonorrhea and chlamydia with a urine test. In addition, these patients were also offered the opportunity to be tested for syphilis and HIV. More than 90 percent (93%) were screened for syphilis and about three-quarters (72%) were tested for HIV (results not included in this analysis).

The study showed that the overall number of individuals who were tested for gonorrhea and chlamydia at the 10 clinics increased by 23 percent after Express Visits were routinized (from 16,128 in 2005 to 19,875 in 2006). While the number of physician visits remained roughly the same during the two time periods (18,449 in 2005 vs. 18,421 in 2006), the Express Visit option made it possible for an additional 4,588 tests to be performed.

Of those screened through the Express Visit option, close to one in ten (8.8%) tested positive for either gonorrhea or chlamydia (1.0% for gonorrhea and 8.2% for chlamydia; some patients were co-infected). This suggests high STD prevalence – even among those with no symptoms or known exposure to STDs. In addition, the researchers found that Express Visits permitted a greater proportion of symptomatic patients to be examined by doctors (73.6% in 2005 vs. 85.6% in 2006), enabling limited physician resources to be focused where they were needed most.

Overall, the analysis showed that the total number of gonorrhea and chlamydia diagnoses increased by 17 percent after Express Visits were routinized (from 2,231 in 2005 to 2,617 in 2006). The proportion who received treatment within 30 days remained stable (91.0% in 2005 and 93.0% in 2006) – indicating that the Express Visit option did not negatively impact the ability of the clinics to treat people in a timely manner.

The researchers believe that Express Visits may help other clinics significantly expand current STD screening and treatment services, while allowing limited clinician resources to be directed to examining symptomatic patients.