Sensitivity of 20-minute voiding intervals in men testing for Chlamydia trachomatis

Area of Science:

• Urology
• Infectious Diseases
• Diagnostic Microbiology

Background:

• Current guidelines recommend men abstain from urination for at least 1 hour before urine testing for Chlamydia trachomatis.
• However, recent research indicates that recent urination may not significantly affect the sensitivity of nucleic acid amplification tests (NAATs).

Purpose of the Study:

• To evaluate the sensitivity of Chlamydia trachomatis testing using urine samples collected just 20 minutes after the last void.
• To assess the feasibility of reducing the standard 1-hour pre-test voiding interval.

Main Methods:

• The study included men diagnosed with urethral Chlamydia trachomatis infection.
• Two first-void urine samples were collected: one after the standard 1-hour wait and another 20 minutes later.
• Samples were analyzed using Roche COBAS Amplicor PCR, with the 1-hour sample serving as the reference standard.

Main Results:

• Out of 31 men with confirmed chlamydia infection, 29 (93.5%) tested positive with samples collected at the 20-minute post-void interval.
• The 95% confidence interval for sensitivity at 20 minutes was 78.6%-99.2%.

Conclusions:

• A 20-minute voiding interval demonstrates reasonably high sensitivity for detecting Chlamydia trachomatis in men compared to standard intervals.
• Relaxing the 1-hour voiding restriction could enhance opportunistic screening efforts for chlamydia.