Testing Pooled Specimens With the Abbott Alinity m STI Assay: Four Years' Experience

Area of Science:

• Clinical diagnostics
• Molecular biology
• Public health

Background:

• The Alinity m STI assay detects Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Mycoplasma genitalium (MG), and Trichomonas vaginalis (TV).
• Specimen pooling is generally not recommended for STI testing due to potential inhibition.

Purpose of the Study:

• To evaluate the efficacy of pooled specimens for STI detection using the Alinity m STI assay.
• To assess inhibition rates and detection performance of pooled samples.

Main Methods:

• Preliminary validation of pooled samples using 13 known positive specimens.
• Retrospective analysis of 5324 pooled specimens for CT/NG detection.
• Subset analysis of 277 pooled specimens for MG detection on the Alinity m STI system.

Main Results:

• Preliminary validation showed no inhibition in pooled samples.
• Retrospective analysis: 18.1% of pooled samples were positive for CT/NG (CT: 6.8%, NG: 9.0%, CT & NG: 2.3%).
• MG was detected in 70.4% of tested pooled specimens with only 1.0% inhibition.

Conclusions:

• Pooled specimens demonstrate low inhibition rates and reliable detection of common STIs.
• Specimen pooling can be a valuable strategy for laboratories facing specimen volume restrictions.