[Modern diagnosis of Chlamydia trachomatis infections].

Chlamydia trachomatis is the most frequent sexually transmitted bacterial infection. Tests to diagnose C. trachomatis infections include growth on cell culture and assays detecting bacterial antigens or nucleic acids. Until recently, culture was considered the gold standard of testing because of its high specificity. However, the sensitivity of culture is limited. Nucleic acid amplification tests (NATs) have the highest sensitivity and are almost as specific as culture. They are best suited for screening. Chlamydial antigen EIAs are considerably less sensitive and specific, resulting in low positive predictive values, especially when low-prevalence populations are studied. Thus, positive results of chlamydia antigen EIAs should be confirmed by another test.