Evaluation of the diagnostic performance of an immunochromatographic test for Chlamydia trachomatis

Objectives

To evaluate the diagnostic performance of different brands of immunochromatographic test (ICT) reagents for Chlamydia trachomatis using homogenized samples to provide a reference for reagent quality control.

Methods

Eight commercially available ICT reagents were evaluated, of which three used the latex method and five used the colloidal gold method. Analytical performance evaluation using a pure culture broth of C. trachomatis, as well as clinical application validation using cervical epithelial cell samples acquired from the research subjects, were conducted. The concentration of C. trachomatis was quantified using a nucleic acid amplification test.

Results

The limit of detection (LOD) of different ICT reagents in the analytical performance evaluation varied from 9.5 × 10³ to 1 × 10⁵ IFU/mL, and only one reagent met the LOD specified in the manufacturer's instructions. Likewise, only one reagent in the clinical application validation achieved the analytical LOD, four reagents were 2.1–4.2-fold of the analytical LODs, and three reagents failed to detect positive results in clinical samples.

Conclusions

The diagnostic performance of different methods and different brands of ICT reagents in clinical practice was different from the manufacturer's instructions and the results of laboratory evaluation. The diagnostic performance of reagents should be evaluated before they are actually used in clinical practice.