Evaluation of Sanofi Diagnostics Pasteur Chlamydia Microplate EIA shortened assay and comparison with cell culture and Syva Chlamydia MicroTrak II EIA in high- and low-risk populations.

Seven hundred thirty-two female urogenital samples were collected for Chlamydia trachomatis testing by both the Sanofi Diagnostics Pasteur (Chaska, Minn.) Chlamydia Microplate EIA by the shortened protocol and the Syva (San Jose, Calif.) MicroTrak II EIA, and the results were compared with those obtained by cell culture. For the analysis of samples from female patients, the patients were divided into high- and low-risk categories. An additional 121 male urethral samples were collected and tested by the Sanofi Microplate EIA and cell culture; for the analysis of samples from male patients, the patients were divided into asymptomatic and symptomatic categories. All specimens positive by enzyme immunoassay (EIA) were confirmed by a blocking assay following the respective manufacturer's instructions. Specimens negative by EIA that fell within a gray zone 30% below the cutoff and negative cultures with one or more corresponding positive EIA results were tested further by cytocentrifugation and direct immunofluorescent assay. The overall sensitivity, specificity, positive predictive value, and negative predictive value for Syva versus culture were 94, 98.8, 85.5 and 99.6%, respectively. After resolution, the results were 94.5, 99.6, 94.5, and 99.6%, respectively. The parallel results for the Sanofi Microplate EIA versus culture were 94.0, 98.7, and 83.9, and 99.6%, respectively, and after being resolved, the results were 94.9, 100, 100, and 99.6%, respectively. In the small male population tested, the resolved results of the Sanofi Microplate EIA versus culture demonstrated sensitivity, specificity, positive predictive value, and negative predictive value of 100, 100, 100, and 100%, respectively. The present study demonstrated that the Sanofi Microplate EIA shortened protocol is highly sensitive and specific in comparison with cell culture and the Syva MicroTrak II EIA.