Evaluation of two rapid tests for the diagnosis of Chlamydia trachomatis genital infections

The performance of two new enzyme immunoassays (EIA) for the detection of Chlamydia trachomatis in a practice setting was compared. A consecutive series of 207 female patients seen at an inner-city sexually transmitted disease clinic were tested by cell culture, the Kodak SureCell (SC) and Abbott TestPack Chlamydia (TP) EIAs. In addition 210 male patients, selected by physicians on the basis of the fact that multiple urethral samples could be obtained, were tested by cell culture and SC. The prevalence of infection was 19% in the females and 12.5% in males. The sensitivity, specificity, positive predictive value and negative predictive value for the SC and TP were 88%, 95%, 81%, 97% and 59%, 99%, 95%, 91%, respectively, in the female population. The sensitivity of the SC was significantly greater than that of the TP (p less than or equal to 0.002). The performance values of the SC in men (in the same order) were 64%, 96%, 71% and 95%, respectively. The SC in male patients and the TP in female patients had low sensitivity. The sensitivity of the SC in female patients was significantly higher than that of the TP. However, the SC yielded more false positive results. To determine the utility of these tests in a practice setting further studies are required.