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

Abstract

Background: 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.

Methods: 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: 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.

Conclusion: 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.

Figures

Figure 1

STI screening rates and results using a universal screening protocol

Figure 2

Age distribution of CT and TV infection prevalence