A new point-of-care molecular test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) has the same accuracy as conventional nucleic acid amplification tests (NAAT) when used in the primary care setting, according to a new study published in Sexually Transmitted Infections.
The GeneXpert CT/NG assay (Cepheid, Sunnyvale, CA), introduced in 2013, became the first nucleic acid-based test for CT/NG available for point-of-care use, and in controlled settings the test had a high rate of accuracy compared with established commercial NAAT tests. In this study, the authors looked at how the test performed in routine primary health practices serving communities with a high prevalence of CT and NG infection.
Training was provided in the use of the GeneXpert CT/NG assay to 99 clinicians working at 12 health services in remote areas of Australia. Collected specimens were also sent in parallel to be tested using NAAT. The concordance between the two was then evaluated.
A total of 2486 tests were conducted, and CT concordance was 99.4% (95% CI, 99.1-99.7). The positive concordance was 98.6% (95% CI, 95.9-99.7) and the negative concordance was 99.5% (95% CI, 99.1-99.8).
NG concordance was also high; 99.9% (95% CI, 99.7 100.0) with a positive concordance of 100.0% (95% CI, 97.5-100.0) and a negative concordance of 99.9% (95% CI, 99.7-100.0).
“Molecular testing at the [point of care] could transform management and control of these infections in many endemic settings, including low-/middle-income countries,” wrote the authors.
Causer LM, Guy RJ, Tabrizi SN, et al. Molecular test for chlamydia and gonorrhoea used at point of care in remote primary healthcare settings: a diagnostic test evaluation [published online May 10, 2018]. Sex Transm Infect. doi: 10.1136/sextrans-2017-053443