Background:
Adolescent females have a high burden of several individual STIs; however, there have been few population-based estimates of the overall burden of STIs in this group.

Objective:
To estimate the prevalence of the most common STIs and bacterial vaginosis (BV) among a representative sample of 14-19 year-old females in the U.S.

Method:
Female participants aged 14-19 years in NHANES 2003-2004 underwent testing of (1) urine for Chlamydia trachomatis (CT) using BD ProbeTec (n=793); (2) sera for herpes simplex virus type 2 (HSV-2) using an immunodot assay (n=729); (3) self-collected vaginal swabs for Trichomonas vaginalis (TV) using PCR (n=695), BV using gram stain and Nugent score ≥7 (n=685), and human papillomavirus (HPV) using PCR (n=652). We evaluated prevalence of any of 23 oncogenic HPV types or types 6 or 11, responsible for most genital warts (HR/6/11 HPV). We defined “any STI” as CT, HSV-2, TV, or HR/6/11 HPV.

Result:
Among 838 participants, 404 reported ever having had sex. Weighted prevalence of “any STI” was 25.7 (95% CI: 20.1-32.9) among all female adolescents and 39.5% (95% CI: 31.1-50.3) among those who reported having had sex. The most prevalent STI was HR/6/11 HPV (18.3%), followed by CT (3.9%), TV (2.5%), and HSV-2 (1.9%). The prevalence pattern was similar among those who reported having had sex: HR/6/11 HPV (29.5%), CT (7.1%), TV (3.6%), and HSV-2 (3.4%). Among those with any STI, 15% had >1. Almost 25% of female adolescents had BV, regardless of sexual experience. Applying these estimates to 2007 census data, we expect >3.2 million prevalent cases of these STIs and >3 million BV cases among U.S. 14-19 year-old females.

Conclusion:
STI prevalence is high among U.S. adolescent females. Prevention of STIs and their complications remains an urgent public health priority for this group.

Implications:
Public health efforts should be increased to prevent STIs among adolescents.