New Urine Test Allows for Detection of Chlamydia at Point of Care

A newly developed diagnostic test can detect Chlamydia trachomatis in less than 20 minutes, making it easy to perform at point of care (POC) during a patient visit, researchers report in The Journal of Molecular Diagnostics.

The test uses recombinase polymerase amplification (RPA), a nucleic acid amplification technique, to detect C trachomatis in urine samples. The researchers report that this new method is significantly less laborious, less time-consuming, and less expensive than current methods. They cite the relative simplicity of the test as a reason for integrating it into numerous POC settings.

The test does not require the purification of total DNA from the urine sample and, therefore, eliminates the need for the specialized equipment that is required in the existing, and widely used, polymerase chain reaction–based techniques for testing C trachomatis.

"The assay enables highly specific C trachomatis detection with sensitivity levels significantly improved compared to currently available C trachomatis POC assays," said lo Langel, PhD, Professor of Molecular Biotechnology, University of Tartu, Estonia, and Professor of Neurochemistry, Stockholm University, Sweden, and one of the authors.

In offering evidence of the new assay’s potential reliability, the researchers said initial analysis of a small patient population showed the new assay's performance indicated a specificity of 100% and a sensitivity of 83%.

"The alarmingly poor performance of the available POC tests for C trachomatis has limited their wider use, and there is a clear requirement for more sensitive and cost-effective diagnostic platforms. Hence, the need for an applicable on-site test that offers reasonably sensitive detection," said Langel.

The assay was tested on urine samples from 70 patients (51 females and 19 males) attending a sexual health clinic in Estonia. The samples were tested in parallel using RPA and Roche Cobas Amplicor C trachomatis assays.

Fifty-eight samples tested negative in both assays. No false negatives were detected.

Of the 12 samples that tested positive using the Roche assay, 10 tested positive in the RPA reaction. In addition, of the 12 patients who tested positive, 9 were asymptomatic.

Pertinent Points:
- A new diagnostic test for Chlamydia trachomatis can produce results faster and is less expensive than existing methods, researchers report.
- Initial analysis of 70 patients showed the new assay's performance indicated a specificity of 100% and a sensitivity of 83%.

References:

Krolov K, Frolova J, Tudoran O, et al. Sensitive and rapid detection of Chlamydia trachomatis by recombinase polymerase amplification directly from urine samples. J Mol Diagn. 2014;16:127-135.