Vaginal Swab vs Urine for Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis: A Meta-Analysis

Purpose: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are the 2 most frequently reported notifiable sexually transmitted infections (STIs) in the United States, and Trichomonas vaginalis (TV), although not a notifiable disease, is the most common curable non-viral STI worldwide. Women bear a disproportionate burden of these infections and testing is necessary to identify infections. Although vaginal swabs are the recommended sample type, the specimen most often used among women is urine. The objective of this meta-analysis was to assess the diagnostic sensitivity of commercially available assays for vaginal swabs vs urine specimens from women.

Methods: A systematic search of multiple databases from 1995 through 2021 identified studies that (1) evaluated commercially available assays, (2) presented data for women, (3) included data obtained from the same assay on both a urine specimen and a vaginal swab from the same patient, (4) used a reference standard, and (5) were published in English. We calculated pooled estimates for sensitivity and the corresponding 95% CIs for each pathogen as well as odds ratios for any difference in performance.

Results: We identified 28 eligible articles with 30 comparisons for CT, 16 comparisons for NG, and 9 comparisons for TV. Pooled sensitivity estimates for vaginal swabs and urine, respectively, were 94.1% and 86.9% for CT, 96.5% and 90.7% for NG, and 98.0% and 95.1% for TV (all P values <.001).

Conclusions: Evidence from this analysis supports the Centers for Disease Control and Prevention's recommendation that vaginal swabs are the optimal sample type for women being tested for chlamydia, gonorrhea, and/or trichomoniasis.