Enzyme-linked immunoabsorbent assays in the detection of Chlamydia trachomatis: how valid are they?

Two enzyme-linked immunoabsorbent assays (Chlamydiazyme, Abbott Laboratories, North Chicago, IL, and IDEIA, Boots-CellTech Diagnostics Inc., East Hanover, NJ) specific for the detection of Chlamydia trachomatis antigen were used to assess 451 cervical specimens. All specimens obtained from the subjects were also simultaneously cultured for Chlamydia. Both assays identified 90.9% (20/22) of the culture positive cases. Chlamydiazyme identified two and IDEIA three additional specimens as positive. Of these additional positive tests, one of two Chlamydiazyme and three of three IDEIA specimens were confirmed as positive by the direct fluorescent antibody technique (MicroTrak, Syva Co., Palo Alto, CA). Given the inexpense, availability, ease of performance, high sensitivity (91%), and specificity (99%) of these tests, both should become valuable tools to objectively assess women at risk for this common sexually transmitted disease.