Diagnosis of Chlamydia trachomatis in Russia--in-house PCR assays may be effective but overall optimization and quality assurance are urgently needed.

In the present study, the performance of the cell culture method, two non-Russian direct immunofluorescence (DIF) assays, and three different in-house polymerase chain reaction (PCR) tests used in St. Petersburg, Russia, for detection of Chlamydia trachomatis in urogenital specimens was evaluated. A total of 650 patients were examined and it was most disquieting that previous C. trachomatis positivity with Russian DIF assays could - 7 days later - be confirmed only in 26% of the women and 30% of the men. Overall, the highest diagnostic sensitivity was obtained using PCR analysis. However, the sensitivity varied significantly: from 79% to 100% between the different PCR assays, sex of the patients, and type of samples. The highest sensitivity was obtained for female vaginal and male urine samples (100%). The specificity of the PCR assays varied from 97% to 100%. The sensitivity of cell culture and both the examined DIF assays was low, i.e. it varied from 46% to 56% and 55% to 75%, respectively. Meanwhile, cell culture was 100% specific and the DIFs showed a specificity varying from 99% to 100%. In conclusion, in a Russian perspective, adequate in-house PCR methods may be used quite effectively for detection of C. trachomatis in invasive as well as non-invasive clinical material. Simultaneous analysis of two different specimens from women resulted in a significantly increased detection rate of C. trachomatis. Nevertheless, in Russia the need for optimization and quality assurance of diagnostic methods for C. trachomatis, especially Russian DIF assays, has to be emphasized.