Comparison of an enzyme immunoassay (Ortho) with cell culture and immunofluorescence for the detection of genital chlamydial infection.

An enzyme immunoassay (EIA) test (Ortho Diagnostic Systems Ltd) was evaluated against cell culture for the detection of chlamydial genital infection. Specimens were obtained from 409 patients (204 men and 205 women). Sensitivity, specificity, predictive value of a positive result (PVP) and predictive value of a negative result (PVN) for the new test compared to cell culture were respectively 73.1%, 93.8%, 63.3% and 96% for men and 80%, 95.6%, 71.4% and 97.2% for women. Discrepancies were further evaluated by repeating the EIA, and by direct immunofluorescence (IF) on the EIA transport buffer. The sensitivity, specificity, PVP and PVN of the EIA against the combination of cell culture and direct IF were respectively 76.7%, 96%, 76.7% and 96% for men, and unchanged for women. Overall agreement between the EIA and the combination of cell culture and direct IF was 93.4%. The EIA is rapid and simple to perform and does not require elaborate equipment.