Detection of Chlamydia trachomatis in Endocervical Swabs Using Molecular (PCR) and Enzyme Immunoassay Techniques

Abstract

Chlamydia trachomatis is an obligate intracellular bacteria characterized by a biphasic developmental cycle of replication. The organism is recognized as one of the major causes of sexually transmissible human bacterial infection throughout the world. Since there are no previous studies dealing with chlamydial diagnosis in our area, therefore, a comparative study to compare between the diagnostic performance of a PCR and EIA techniques was conducted, to detect C. trachomatis infection in 109 endocervical swab specimens. These specimens were collected from female participants, whose ages ranged between 18-52 years with a median age of 29 year, attending gynecology and infertility clinics in Gaza with different complains. The results obtained showed that the overall confirmed detection rate of C. trachomatis was 20%. Infection rate of C. trachomatis by plasmid PCR was 21.1%. While, by chromosomal (MOMP) PCR was 17.4% and by EIA was 19.1%. Diagnostic consistency and diagnostic accuracy were statistically tested. There was no statistical significant difference between PCR and EIA techniques. The sensitivity of EIA, MOMP- PCR and plasmid- PCR were 73%, 86%, and 100%, respectively. Meanwhile the specificity for EIA, plasmid- and MOMP- PCRs were 94%, 98%, and 100%, respectively. Efficiency of EIA, MOMP –, and plasmid – based PCR assays were 90%, 97%, and 98%, respectively. The highest rate of infection was observed in the participants from Northern Gaza Strip and among participants with elementary education level, intrauterine contraceptive device (IUCD) users, and secondary infertility. Cervical discharge, especially of a mucopurulent character, and contact bleeding were suitable markers for having genital chlamydial infection.These signs were significantly more often expressed in C. trachomatis positive women in our study (P= 0.0002). There was also a significant statistical relationship between chlamydial infection and infertility (P=0.049). The Odds ratio of development of outcomes of cervicitis, contact bleeding, and infertility were 5.9 (95% CI 2.15-15.97), 4.3 (95% CI 1.27-14.45), and 2.6 (95% CI 0.99-6.85), respectively. PCR proved to be superior and more efficient in the diagnosis of C. trachomatis than EIA, therefore it should be used as a technique of choice in diagnosis of C. trachomatis. Although financial constraints may impede the routine use of molecular diagnostic methods in Palestine, it should be borne in our minds that the cost arising from the clinical sequelae of leaving genital C. trachomatis infection undiagnosed and untreated may exceed the cost of these diagnostic methods.