Screening of Chlamydia trachomatis:: Is the diagnostic efficacy good enough?

Objective: In the background of discrepant results of C, trachomatis testing in women with suspected genital infections, three different tests have been compared. Method: 594 endocervical swabs were collected from women visiting the family planning clinic in Aarau. Each of the following tests was evaluated: Cobas Amplicor Chlamydia trachomatis, if Chlamyset, and Chlamydia IF direct. If one of these three tests was positive, the fixed material on the slides was scraped off, and a PCR was performed. Results: 15 out of 594 sam pies were 'true'-positive. PCR recognized 14 of them, the IF Chlamyset 13, and the Chlamydia IF 8, With the IF Chlamyset 37 samples were false-positive. Conclusions: PCR testing exhibits a good sensitivity and a high specificity, but we think that the sensitivity can be increased by improving the sample preparation step. The Chlamydia IF direct has a good specificity, but a rather low sensitivity. It should be noted that the FCR has the potential to become a new gold standard for the detection of C. trachomatis. Copyright (C) 2001 S. Karger AG, Basel.