STD Quarterly

STD alert: 50% of urban teen girls acquire STDs within 2 years of first sexual activity

Repeat infection common, 25% reinfected within 6 months of treatment

Half of urban teenage girls may acquire at least one of three common sexually transmitted diseases (STDs) — chlamydia, gonorrhea, or trichomoniasis — within two years of becoming sexually active, according to results of a recent study.1

Researchers at the Indiana University School of Medicine and Regenstrief Institute, both in Indianapolis, followed 381 females enrolled at ages 14-17 in three inner-city adolescent medicine clinics. At enrollment, teens completed a questionnaire and an interview to establish lifetime and recent sexual behaviors, as well as lifetime STD history, and were tested via cervical and vaginal specimens. Study participants returned for follow-up every three months for interviews and testing. In alternating quarters, they were instructed to complete daily behavioral diaries and submit weekly self-administered vaginal swabs for STD testing.

By age 15, 25% of the women acquired their first STD, with chlamydia the most common first infection, researchers found. Depending on the organism, within four to six months after treatment of the previous infection, a quarter of the women were reinfected with the same organism, says Wanzhu Tu, PhD, associate professor of medicine at the Indiana University School of Medicine and a Regenstrief Institute investigator.

Within two years, about 75% of participants with an initial STD were diagnosed with a second infection, although not necessarily of the same type. Within four years of an initial infection, 92% of the participants had a subsequent STD, researchers found. "To our knowledge, this study provides the first data on the timing of the initial sexually transmitted infection [STI] and subsequent STI following the onset of sexual activity in urban adolescent women," says Tu.

As a result of their findings, the Indiana researchers call for STI screening in sexually active teenage girls within a year after first intercourse and for retesting of infected females every three to four months. Continuing surveillance might be necessary due to the continuing high risk of infection, even if the first rescreening test result is negative, they conclude.1

When to start screening?

In your practice, when do you begin screening teens for STDs? Researchers in the Indiana study found that STD screening might not be initiated until several years after sexual activity begins, especially for girls with earlier onset of sexual activity.1

The U.S. Preventive Services Task Force recommends screening all women younger than age 25 years for chlamydia and gonorrhea.2,3 The Centers for Disease Control and Prevention suggests annual chlamydia screening for sexually active women within one year of first sexual intercourse and gonorrhea screening for women at increased risk until age 26.4 However, neither group has made evidence-based recommendations on the most appropriate starting age and the most appropriate frequency of screening, the Indiana researchers note.1

Some clinicians might be reluctant to address sexual activity with younger teens when it comes to STD prevention. This reluctance must be overcome, says Dennis Fortenberry, MD, MS, professor of pediatrics at the Indiana University School of Medicine and senior author of the current study. Discussions about sexuality and sexual activity between adolescents and clinicians gives clinicians information needed to accomplish all of the activities of a clinic visit: education, reassurance, diagnosis and treatment, prevention and, when necessary, referral, he notes. Discussions of sexuality and sexual behavior not only will identify adolescents with needs for STD screening or contraception, but also might identify those with questions about sexual orientation, normal development, or sexual violence, Fortenberry observes.

"Establishing an empathetic relationship where confidential matters may be discussed with an objective, knowledgeable person is the cornerstone of all clinician-patient relations," says Fortenberry. "This applies to adolescent patients as well as adults."

Why might clinicians be reluctant to address issues of sexuality and sexual activity? Fortenberry points to several sources: clinicians' personal discomfort with sexual issues, perceived lack of training and expertise, perception that parents will be offended if such issues are addressed, and perception that adolescents will not be honest in response to a clinician's inquiry about sex.

"None of these serve as a sufficient reason to omit this aspect of a clinical encounter with adolescents," Fortenberry states.

Let's talk about sex

When taking an adolescent sexual history, educate and empower to facilitate behavior change, says Yolanda Wimberly, MD, MSc, assistant professor of clinical pediatrics at the Morehouse School of Medicine in Atlanta. Wimberly spoke on providing reproductive health care to teens at the 2008 Contraceptive Technology Quest for Excellence conference in Atlanta.5

Use motivational interviewing. Ask teens if they think their behavior is risky and what they can do to change it, she says. Meet teens where they are, and empower them to make the changes they want. Avoid lecturing, and be clear in your counseling, Wimberly advises. Ask teens if they understand or quiz them on what you just counseled. Help teens set goals for change, she states.

In questioning teens about sexual behavior, she lists the following "do's": assure confidentiality; explain why you are asking sensitive questions; and ask the teen to describe specific sexual behaviors and contraceptive practices.

What are some approaches to avoid? Wimberly notes the following "don'ts":5

  • Don't ask, "Are you sexually active?"
  • Don't use gender-biased pronouns when referring to sexual partners.
  • Don't use judgmental language.
  • Don't use slang unless the teen uses it first.

To assess sexual behavior, the following questions may be asked:

  • How old were you when you first had voluntary sex?
  • What was the date of your last intercourse?
  • Do you have a current partner? How long have you been with your partner?
  • How many sexual partners have you had?
  • How many sexual partners have you had in the past three months?5

Help teens to understand the scope of STDs in their age group. Results of a 2008 study indicate that 26% of women ages 14-19 are infected with at least one of the most common STDs: human papillomavirus (HPV), chlamydia, herpes simplex virus, and trichomoniasis.6

Why are youth and young adults more at risk for STDs? Several factors come into play, says Wimberly. Many teens might have poor knowledge or misperceptions of STD risks for themselves, which leads to deficits in decision-making skills. Teens also might be using condoms incorrectly or infrequently, she notes.

To assess and facilitate condom use, ask the question, "Did you use condoms the last time you had sexual intercourse?" Follow up with the question, "How often do you use condoms: all of the time, most of the time, or some of the time?" To check condom skills, Wimberly suggests asking the teen, "Can you tell me how to put on a condom?"


  1. Tu W, Batteiger BE, Wiehe S, et al. Time from first intercourse to first sexually transmitted infection diagnosis among adolescent women. Arch Pediatr Adolesc Med 2009; 163:1,106-1,111.
  2. U.S. Preventive Services Task Force. Screening for chlamydial infection: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med 2007; 147:128-134.
  3. U.S. Preventive Services Task Force. Screening for gonorrhea: Recommendation statement. Ann Fam Med 2005; 3:263-267.
  4. Centers for Disease Control and Prevention, Workowski KA, Berman SM. Sexually transmitted diseases treatment guidelines. MMWR Recomm Rep 2006; 55(RR-11):1-94.
  5. Wimberly Y. Providing reproductive health care to adolescents. Presented at the 2008 Contraceptive Technology Quest for Excellence conference. Atlanta; October 2008.
  6. Forhan SE. 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. Presented at the 2008 National STD Prevention Conference. Chicago; March 2008.