Sexually transmitted infection prevalence in a population seeking no-cost contraception

We used universal screening to determine the prevalence rates of Neisseria gonorrhoeae (GC), Chlamydia trachomatis (CT), and Trichomonas vaginalis (TV) in 9256 women enrolling into a contraceptive study.

We offered screening using nucleic acid amplification or culture to all participants enrolling into the Contraceptive CHOICE Project. Demographic characteristics were collected through staff-administered questionnaires. Univariate and multivariable analyses were performed to assess the risk of sexually transmitted infection at baseline and to compare risk profiles of CT and TV.

Results were available for 8347 consenting women with satisfactory results; 656 (7.9%) were tested positive for 1 or more infections. Approximately one third of participants were older than 26 years, and half were identified as African American. There were 35 cases of GC for a prevalence of 0.4% (95% confidence interval [CI], 0.3-0.6), 260 cases of CT for a prevalence of 3.1% (95% CI, 2.8-3.5), and 410 cases of TV for a prevalence of 4.9% (95% CI, 4.4-5.4). Black women were more likely to be tested positive (odds ratio, 3.95; 95% CI, 3.08-5.06) compared with white women and accounted for 81.3% of cases. T. vaginalis was more prevalent in black women (8.9%) compared with white women (0.9%). Older age was a risk factor for TV, whereas younger age was associated with CT. Of the 656 positive cases, 106 (16%) were diagnosed in women older than 25 years, falling outside traditional screening guidelines.

We found GC, CT, and TV to be more prevalent than current national statistics, with TV being the most prevalent. Current screening recommendations would have missed 16% of infected women.