Evaluation of Alinity m STI Assay for Simultaneous Detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium in Female Urogenital Specimens

BACKGROUND: The Alinity m STI is a nucleic acid amplification testing for the detection of Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV) and Mycoplasma genitalium (MG) in one assay. This study evaluated the performance of the Alinity m STI in comparison with other commonly used Food and Drug Administration-cleared assays and laboratory-developed tests across multiple female urogenital specimens. METHODS: Clinician-collected and self-collected vaginal swab, endocervical swab, and urine specimens were collected from symptomatic and asymptomatic women across the United States. The Alinity m STI results were compared with the Composite Comparator Algorithm to establish specimen-specific agreement with 6 Food and Drug Administration-cleared assays and 2 laboratory-developed test. RESULTS: In this study population, the prevalence of single infections ranged from 0.8% (NG) to 7.6% (TV), with 3.4% of individuals coinfected with at least 2 pathogens. The overall positive agreements for clinician-collected and self-collected vaginal swab and for endocervical swab were ≥97.5%, ≥98.0%, and ≥97.3%, respectively, for all 4 analytes, with TV showing the lowest agreement for these sample types. The overall positive agreement for urine was ≥99.2% for all 4 targets. The κ score ranged from 0.84 to 0.99 across all analytes and specimen types. CONCLUSIONS: The Alinity m STI assay showed excellent concordance with the comparator assays, as demonstrated by strong κ scores in female urogenital specimens.