Comparison of Roche Cobas Amplicor and Abbott LCx for the Rapid Detection of Chlamydia trachomatis in Specimens From High-Risk Patients

Objective: To evaluate two automated amplification systems for the detection of Chlamydia trachomatis in urogenital specimens, the Cobas Amplicor (Roche Diagnostic Systems, Branchburg, NJ) and the LCx (Abbott Laboratories, Abbott Park, IL). Study Design: The two systems were compared testing specimens from 302 high-risk patients, including 98 female cervical swab specimens and 204 male urine specimens. The patients attended the state STD clinic in Reykjavik, Iceland, either because of symptoms or as a result of contract tracing. Results: The prevalence of C. trachomatis infection was 15.3% in women and 13.2% in men. For the male urine specimens, the sensitivity and specificity were 100% and 99.4% for the Cobas Amplicor and 74.1% and 100% for the LCx. In the cervical swabs, both systems detected all 15 true-positive specimens. The internal control used with the Cobas Amplicor detected inhibition in 2% of the male urine and 20% female cervical swabs, respectively. Conclusion: The Cobas Amplicor demonstrated slightly better sensitivity than LCx in male urine specimens. Both systems offer the benefits of automation for routine diagnostic testing.