URINE AS A DIAGNOSTIC SPECIMEN FOR THE DETECTION OF CHLAMYDIA-TRACHOMATIS IN MALAYSIA BY LIGASE CHAIN-REACTION

Background and Objectives: Noninvasive urine screening for Chlamydia t rachomatis infections offers a valuable public health tool, which coul d be of vast importance in chlamydial control programs. The authors ev aluated a new DNA amplification method, ligase chain reaction (LCR). G oals: The goal was to ascertain whether urine testing could be used as screening method to detect C. trachomatis infections in commercial se x workers, patients at sexually transmitted diseases clinic, and asymp tomatic patients in Kuala Lumpur, Malaysia. Methods: First-void urine specimens from 300 men and 300 women were tested by LCR, as well as by a commercially available enzyme immunoassay. The LCR assay amplifies specific sequences within the chlamydial plasmid with ligand-labeled p robes, and the resultant amplicons are detected by an automated immuno assay. Specimens with discrepant results were confirmed by another LCR of the specimen that targeted the gene for the major outer membrane p rotein (OMP1). Results: There were 31 LCR-positive male urine and 37 L CR-positive female urine specimens. The resolved sensitivity and speci ficity for the LCR of the male urine specimens were 100% and 99.6%, re spectively, whereas for female urine specimens, the sensitivity and sp ecificity were 100% and 98.5%, respectively. After resolution of discr epant test results by OMP1 LCR, the prevalence was 10% for men and 11% for women. The urine enzyme immunoassay was not useful in diagnosing C. trachomatis infections in either men or women, as the resolved sens itivities were 10% and 15.2%, respectively. The specificities were 99. 6% for men and 98.9% for women. Conclusions: Testing first-void urine specimens by LCR is a highly sensitive and specific method to diagnose C. trachomatis infections in men and women, providing health care wor kers and public health officials with a new molecular amplification as say that uses noninvasive urine specimens for population-based screeni ng purposes.