Serologic detection of sexually transmitted diseases caused by Chlamydia trachomatis

163 patients were examined for the presence of C. trachomatis by cultivation and concurrently sera were examined by the ELISA method for the presence of antibodies against C. trachomatis. Significant titres of antibodies were detected in less than half the patients with infection proved by cultivation. Antibodies were found more frequently in patients with a complicated course of the disease. In approximately 3% of the patients, where the agent was not detected by cultivation, antibodies were found in high titres. The author evaluated also the possibility to use the complement fixation reaction with ornithose antigen for the diagnosis of sexually transmitted infections caused by C. trachomatis. According to the author's results this method cannot be used. Serological evidence of Chlamydia infection is not a method of first choice for the diagnosis of sexually transmitted infections caused by C. trachomatis, but is an important supplementary method for the diagnosis, mainly of complicated infections.