# Accuracy of self-collection versus cervical sampling for the molecular diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae in women attending gynecological services

## TL;DR

The study compares self-collection and urine samples to cervical swabs for detecting Chlamydia and Gonorrhea in women, finding self-methods reliable and practical.

## Contribution

Demonstrates that self-collection and first-catch urine samples are highly sensitive and specific for detecting Chlamydia trachomatis.

## Key findings

- Self-collection was 100% sensitive and specific for detecting Chlamydia trachomatis.
- First-catch urine samples showed 90% sensitivity and 99% specificity compared to cervical brushing.
- No symptoms were associated with Chlamydia trachomatis positivity, emphasizing the need for asymptomatic testing.

## Abstract

Successful measures to address the increasing prevalence of sexually transmitted infections (STIs) require practical and accessible education and detection programs.

The ability to detect Chlamydia trachomatis and Neisseria gonorrhoeae may be hindered by a lack of adherence to proper cervical sampling. To address this, we compared the sensitivity and specificity of self-obtained samplings, such as self-collection and first-catch urine samples, to cervical samples taken by a practitioner using the nucleic acid amplification test (NAAT) cobas® 4800 for C. trachomatis and N. gonorrhoeae in 244 women attending gynecological services in Quito, Ecuador. Regardless of sampling method, only 12 patients tested positive for C. trachomatis (4.9% prevalence, 95% CI 2.8 to 8.4%), and no samples tested positive for N. gonorrhoeae.

The analysis revealed that self-collection was 100% sensitive (95% CI 66.4% to 100.0%) and 100% specific (95% CI 98.25%-100%), and first-catch urine was 90% sensitive (95% CI 55.5% to 99.8%), and 99% specific (95% CI 96.5% to 99.9%) compared to cervical brushing for the detection of C. trachomatis. No symptoms were associated with a positive C. trachomatis result, highlighting the need for testing even in asymptomatic patients. Furthermore, having a stable intimate relationship in the past year was associated with a negative result for C. trachomatis (χ2 14.01, p < 0.001).

This study demonstrates the feasibility and reliability of self-collection and first-catch urine samples as alternative methods for detecting Chlamydia trachomatis and has practical implications for improving STI detection and management programs.