LABORATORY TO LABORATORY VARIATION IN CHLAMYDIA-TRACHOMATIS CULTURE PRACTICES

Goal of this Study: To compare laboratory to laboratory variability in methods of cell culture for Chlamydia. trachomatis performed by North American research laboratories. Study Design: The authors administere d a standardized 54-question survey to laboratories that had published articles in any of three medical journals reporting on the use of cel l culture to identify individuals with C. trachomatis infection. Labor atory to laboratory variability in specimen collection, specimen trans port conditions, culture methodologies, and criteria for evaluation of culture outcomes was examined. Results: Twenty-five (93%) of 27 labor atories responded to the survey, Only two of 54 questions mere answere d uniformly by all responding laboratories. All laboratories reported vortexing or sonication of specimens before culture inoculation and ce ntrifugation of inoculated cultures prior to incubation. In contrast, substantial variation was noted in specimen collection devices, specim en transport conditions and times, culture format, culture procedures, and criteria for identifying positive cultures. Conclusion: Although this study did not evaluate the sensitivity of chlamydia cell cultures performed in different laboratories, there was substantial laboratory to laboratory variation in nearly every facet of culture evaluated. L aboratory to laboratory variation in chlamydia cell culture sensitivit y likely accounts for part of the substantial variability in published evaluations of the sensitivity of nonculture chlamydia diagnostic tes ts.