DIRECT FLUORESCENT-ANTIBODY CONFIRMATION OF CHLAMYDIAL ANTIGEN BELOW THE DETECTION THRESHOLD OF THE CHLAMYDIAZYME ENZYME-LINKED-IMMUNOSORBENT-ASSAY

Of 4,000 endocervical specimens tested with the Chlamydiazyme enzyme-linked immunosorbent assay (Abbott Laboratories), 233 (5.8%) gave positive results (A492 above the cutoff), which were confirmed with a blocking reagent (Abbott). An additional 34 specimens (14.6%) with chlamydial antigen were detected and confirmed with the direct fluorescent-antibody test (Syva) from among those 66 Chlamydiazyme-negative specimens which had A492s that ranged from 0.030 to the cutoff and that could be blocked by greater-than-or-equal-to 50% with the blocking reagent.