comparative study for detection of chlamydia trachomatis antigen and antibody in Egyptian Patients with chronic urogenital infection

ABSTRACT

Urethral, cervical, first voided urine [FVU] and serum samples from 140 patients with chronic urogenital infections, either schistosomal [Group [I]] or non-schistosomal [Group [II]], and 30 healthy controls [Group [III]] were tested. Two commerically available antigen detection tests [DFA and EIA] and two antibody detection tests [IFA on serum and local secretions] were used to determine the most sensitive combination of tests and specimens. DFA on urine sediment was positive in 50.7% [71/140] of patients in groups [I] and [II] [74.65% males and 25. 35% females]. It was considered as the [gold standard] for our calculations relying on the fact that every patient who gave a positive result with this test gave at least one positive result with the other more popular tests. Regarding chlamydial cervicitis, we considered DFA and EIA on cervical smears as the [gold standard]. In groups [I] and [II] patients, DFA, EIA and IFA tests on urethral smears gave a positivity rate of 46.4%, 42.86% and 30.7% respectively, while IFA on serum gave a rate of 37. 86%.. Cervical smears and secretions tested by both DFA and IFA tests gave positivity rates of 31. 25% for both tests but the EIA gave a rate of 34. 38%. The sensitivities for antigen detection in urethral smears by DFA were 94% in males and 83. 33% in females and by EIA, were 88.68% in males and 72.22% in females. The sensitivities for antibody detction by IFA in urethral secretions were 60.38% in males and 61.11% in females and in serum were 73.58% in males and 77.78% in females. Cervical smears showed sensitivity of 71.43% by DFA and 78.57% by EIA. The sensitivity of DFA on urine sediment was 100%. It is concluded that DFA on urine sediment is absolutely sensitive in screening male cases in a community at risk, like Egypt, and that IFA test on serum can be used as a confirmatory test. In females, testing the urethral smear and urine sediment in addition to cervical specimens offered higher rates of positivity than testing cervical specimens only