Abstract: Objective To determine the sensitivity and specificity of ligase chain reaction(LCR) for the detection of Chlamydia trachomatis in the urine of symptomatic men. Methods First-void urines (FVU) were examined with LCR plasmid assay and urethral swabs were cultured to detect Chlamydia trachomatis in 162 men. Discordant results were resolved with a second LCR directed against a fragment of the major outer membrane protein gene. Test performance was calculated on the basis of an" expanded gold standard". Results The sensitivity and specificity of LCR plasmid assay were 100% and 99.2% respectively, and 82.8% and 100% for urethral swabs culture. Conclusion LCR is a sensitive and specific diagnostic method for Chlamydia trachomatis infection to detect C.trachomatis in FVU, which is a non-invasive diagnostic method for screening Chlamydial trachomatis infection in men.

Key words: Chlamydia trachomatis, Ligase chain reaction, Urine