Evaluation of three immunoassays for detection of Chlamydia trachomatis in urine specimens from asymptomatic males

Abstract

The performances of three commercially available immunoassays (Chlamydiazyme/Antibody Blocking Assay [Abbott Diagnostics, Abbott Park, Ill.], IDEIA [Analytab Products, Plainview, N.Y.], and Microtrak EIA [Syva Co. Palo Alto, Calif.]) were evaluated for the detection of Chlamydia trachomatis in urine specimens from asymptomatic males. Assay results were compared with direct specimen immunofluorescence (DFA) analysis of urine sediment (Syva Microtrak; Syva Co.), which was chosen as the study confirmation assay. An overall Chlamydia prevalence of 7% (24 of 340) was found in our study population, with peak incidences occurring in the adolescent (8 of 93 specimens) and young adult (11 of 146 specimens) age groups. Sensitivity and specificity data among the Chlamydiazyme, IDEIA, and Microtrak enzyme immunoassays (EIAs) were determined to be 79.1 and 99%o, 91.7 and 98%, and 95.8 and 99%o, respectively. The Microtrak EIA and IDEIA products demonstrated sensitivities and specificities equal to or greater than those claimed for urine specimens. The diagnostic accuracies of these assays on asymptomatic subjects, along with the ease of this collection method, suggest a role for these products as screening tools. The sensitivity of the Chlamydiazyme assay was lower than that claimed previously in symptomatic patients, with 5 of 24 positive specimens demonstrating false-negative results. In those cases, centrifugation of the original immunoassay aliquot material and then DFA examination confirmed specimen positivity. Urine immunoassay screening in combination with DFA confirmation (which was chosen because it has antibody epitopic specificity different from that of the primary assay) provides a high degree of diagnostic precision. The use of noninvasive collection methods could result in greater testing compliance among asymptomatic males and, subsequently, could reduce the incidences of both symptomatic and silent chlamydial infections.

Diagnosis of genital Chlamydia trachomatis infections in asymptomatic males by testing urine by PCR

“…For this reason, noninvasive antigen detection tests, such as DIF (11) and EIA (5,9,14), have been proposed as alternative diagnostic means. Two DNA amplification techniques for the detection of urogenital infections due to C. trachomatis have been developed, i.e., PCR and ligase chain reaction (1,6,12,24).…”

Diagnosis of Chlamydia trachomatis infections in asymptomatic men and women by PCR assay

“…This is especially true for men, for whom sensitivities of EIA testing of urethral swab specimens as low as 48% have been reported (19). The sensitivity of EIA testing of FVU specimens from asymptomatic men has also been variable, ranging from 42 to 96% (14,20).…”

Current Methods of Laboratory Diagnosis of Chlamydia Trachomatis Infections

“…For this purpose, urine must be centrifuged and the sediment must be resuspended in the manufacturer's diluent buffer before the test is performed. The performance of IDEIA has been reported in one comparison study to be similar to that of Microtrak EIA but superior to Chlamydiazyme for male urine specimens (113), whereas in another study of male urine, these three EIAs performed similarly (139). Prima EIA performed on urine sediments from asymptomatic males was reported to be more sensitive than previously reported values for Microtrak or Chlamydiazyme EIA, but the study did not directly compare the tests (176).…”