A nonculture test for identification of Chlamydia trachomatis

A clinical trial compared Chlamydiazyme (Abbott Laboratories, North Chicago, Illinois), an enzyme immunoassay being developed for the detection of Chlamydia trachomatis antigens, with isolation of the organism in cycloheximide-treated McCoy cells. Duplicate cervical swab specimens were obtained from 209 women undergoing abortion. C. trachomatis was isolated after subculturing from 18 of them (8.6%). Chlamydial antigens were found with Chlamydiazyme in 13 (72.2%) of the 18. The same number was detected with primary isolation. The specificity of Chlamydiazyme was 98.4%. Overall, 201 of 209 samples (96.2%) were identified correctly with Chlamydiazyme as compared to isolation after subculturing. Therefore, Chlamydiazyme could be used instead of primary isolation in this population.