Chlamydia trachomatis prevalence in unselected infertile couples.

Chlamydia (C.) trachomatis, an obligate intracellular bacterium, is responsible for the most common sexual transmitted disease and infertility. The purpose of this study was to evaluate: a) the frequency of chlamydial infection in unselected infertile couples and b) whether chlamydial infection could be identified in the semen sample as effectively as in the urethral swab of infertile patients. To accomplish this, 73 unselected, consecutive infertile couples were enrolled. Both male and female partners underwent a complete work-up to identify the cause of their infertility. A PCR method was used to detect C. trachomatis in urethral swabs and the semen samples of the male partners and in the cervical swabs of the female partners. C. trachomatis infection was found in 6 couples (8.2%). Three couples had both partners infected, 2 couples had only the male partner infected, and 1 only the female partner. C. trachomatis infection was found in the urethral swab of all 5 men infected, whereas the bacterial DNA was found in the semen sample of 2 of them. These findings suggest that C. trachomatis infection is present in about 8% of unselected infertile couples and that the bacterium should be searched in the male partner urethral swab which has a higher sensitivity.