Chlamydia trachomatis screening in resource-limited countries – Comparison of diagnostic accuracy of 3 different assays

Abstract

Introduction: Commercially available assays were evaluated in order to determine diagnostic accuracy of Chlamydia trachomatis specific tests for screening.
 Methods: The study included 225 sexually active men and women, who were tested for genital chlamydial infection in Institute of Public Health Kragujevac. Three screening tests were used: direct immunofluorescence (DIF) and rapid lateral immunochromatographic test (RT) for qualitative detection of chlamydial antigens and immunoenzyme (ELISA) test for detection of serum levels of anti-chlamydial IgA and IgG antibodies. Diagnostic efficiency of these tests were determined in relation to results obtained by RT-PCR method.
 Results: Statistical significance between the results obtained by RT-PCR as a gold standard and DIF, RT and ELISA were analyzed using chi-square (χ2) test. Statistical analysis showed a significant difference between RT-PCR and analyzed screening tests: DIF (χ2 = 303; p < 0.001), RT (χ2 = 4.19; p = 0.041), serum IgA (χ2 = 4.19; p = 0.041) and serum IgG (χ2 = 67; p < 0.001) which indicates poor agreement between these tests. Large numbers of false positive (FP) and false negative (FN) results were observed for all tested assays. According to Youden’s index, serum IgG and DIF testing demonstrated the most-balanced sensitivity-specificity rate. RT assay exhibits the highest expanded Youden’s index, as well as the best overall diagnostic accuracy.
 Conclusions: None of evaluated screening tests can be recommended as individual method for the diagnosis of acute infection. We suppose that RT-PCR is unlikely to be a cost-effective screening strategy within the Serbian health system.

Evaluation of the diagnostic performance of an immunochromatographic test for Chlamydia trachomatis

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Chlamydia infection resembling ulcerative colitis: case report

“…That is, among the sexually transmitted infections, Chlamydia trachomatis shows sharp geographical differences, but it occurs with a considerable frequency and should be screened more routinely in daily clinical practice. Therefore, although it is known that Chlamydia antibody tests have shown false positive and false negative results (17,18) and do not differentiate a current infection from immunological memory, Tosic-Pajic et al (18) consider the serological tests to be the most suitable screening method in terms of cost-effectiveness.…”

Gonococcal Corneal Perforation in an Adult: Still an Emerging Entity Today

“…Therefore, and given the relatively avascular nature of the cornea in the presented case, we continued systemic therapy with ceftriaxone for 7 days. Complementary to systemic therapy and to prevent collagenase release from destructive corneal lesions [7] and manage any possible co-existing chlamydial infection [8], a systemic doxycycline was added. The intention behind this combined antibiotic therapy was also, apart from enhancing treatment efficacy, to avoid the potential development or spread of cephalosporin resistance [9].…”