Validation of COBAS Taqman CT for the detection of Chlamydia trachomatis in vulvo-vaginal swabs.

Background: Vulvo-vaginal swabs (VVSs) are not validated for use by the manufacturers of two widely used nucleic acid amplification tests (NAAT) for the detection of Chlamydia trachomatis . However, there is evidence that this type of swab is suitable for diagnosis. Objective: To validate the Cobas Taqman CT assay for the detection of C trachomatis in VVS. Method: Women aged 18–24 years attending a genitourinary medicine clinic were invited to take part in the study. Participants provided a self-taken VVS and the results obtained with these samples were compared with those obtained with an endocervical swab collected by a healthcare worker. A total of 267 women took part. Results: 255/267 (96%; 95% CI 92 to 98%) sets of samples gave concordant results. 12/267 (4.5%) VVSs were invalid/inhibitory and so no result was available for these samples. This compared with 2/267 (0.7%) for endocervical swabs. Conclusion: VVS are suitable samples for detecting C trachomatis .