Performance of the Cepheid CT/NG Xpert Rapid PCR Test for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae

TLDR

Rapid tests for Chlamydia trachomatis and Neisseria gonorrhoeae can guide therapy and improve patient care compared to laboratory tests that take days. We compared the Cepheid GeneXpert CT/NG assay to two approved nucleic acid amplification tests in 1,722 female and 1,387 male volunteers. The Xpert assay achieved sensitivities of 97.4–100.0 % for chlamydia and 95.6–100.0 % for gonorrhea across various specimen types, with specificities ≥99.4 % and ≥99.8 %, demonstrating accurate, rapid testing suitable for point‑of‑care use.

Abstract

Tests for Chlamydia trachomatis and Neisseria gonorrhoeae, which can provide results rapidly to guide therapeutic decision-making, offer patient care advantages over laboratory-based tests that require several days to provide results. We compared results from the Cepheid GeneXpert CT/NG (Xpert) assay to results from two currently approved nucleic acid amplification assays in 1,722 female and 1,387 male volunteers. Results for chlamydia in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 97.4%, 98.7%, and 97.6%, respectively, and for urine samples from males, a sensitivity of 97.5%, with all specificity estimates being ≥ 99.4%. Results for gonorrhea in females demonstrated sensitivities for endocervical, vaginal, and urine samples of 100.0%, 100.0%, and 95.6%, respectively, and for urine samples from males, a sensitivity of 98.0%, with all estimates of specificity being ≥ 99.8%. These results indicate that this short-turnaround-time test can be used to accurately test patients and to possibly do so at the site of care, thus potentially improving chlamydia and gonorrhea control efforts.