Can a Clean Catch Urine Sample Be Used to Diagnose Chlamydia and Gonorrhea in Adolescent Females?

PURPOSE: Clean catch urine samples may be an alternative specimen to test for chlamydia and gonorrhea infections. The aim of this study was to determine the sensitivity and specificity of clean urine for chlamydia and gonorrhea in women.

METHODS

This was a noninferiority prospective cohort study of women aged 14-22 years requiring chlamydia and gonorrhea testing. Patients provided a vaginal swab (gold standard), clean urine (test sample), and dirty urine (usual care). All samples were analyzed using Hologic's Aptima Combo2 Assay, a second-generation nucleic acid amplification test. The sensitivity and specificity of the clean and dirty urine were calculated and compared.

RESULTS

Three hundred and twenty-three females were included, mean age 17.0 ± 1.6 years. For chlamydia, 59 participants were positive by vaginal swab. The sensitivity of clean urine to diagnose chlamydia was 86.2% (95% CI: 74.8%-93.1%) and specificity was 98.8% (95% CI: 96.5%-99.8%). The sensitivity of dirty urine to diagnose chlamydia was 89.8% (95% CI: 79.2%-95.6%), and the specificity was 99.6% (95% CI 97.6%-100%). For gonorrhea, 18 participants were positive by vaginal swab. The sensitivity of clean urine to diagnose gonorrhea was 94.4% (95% CI: 72.4%-100%) and specificity was 99.7% (95% CI: 98.0%-100.0%). The sensitivity of dirty urine to diagnose gonorrhea was 100% (95% CI: 79.3%-100%) and specificity was 99.7% (95% CI: 98.0%-100%). Specificity of clean urine was noninferior compared with dirty urine for diagnosing chlamydia (p = .0004) and gonorrhea (p < .0001).

CONCLUSIONS

Clean urine samples may be an alternative option to diagnose chlamydia and gonorrhea in women.