Comparison of Methods for Detection of Chlamydia trachomatis and Neisseria gonorrhoeae Using Commercially Available Nucleic Acid Amplification Tests and a Liquid Pap Smear Medium

Abstract

Annual screening for Chlamydia trachomatis infection is currently recommended for sexually active women 15 to 25 years old and for women older than 25 if they have a new or multiple sex partners and have not used condoms during the previous 3 months. Annual screening for cervical abnormalities using the Pap smear has achieved a substantial reduction in morbidity and mortality from cervical cancer. Screening for Neisseria gonorrhoeae infection has likely contributed significantly to the reduction in the rates of gonococcal infection. The introduction of liquid Pap smear methods using exfoliated cervical cells presents an opportunity to screen for these three conditions using one specimen. We evaluated the preservation of C. trachomatis and Neisseria gonorrhoeae DNAs from ThinPrep liquid media (PreservCyt; Cytyc Corp., Boxborough, Mass.); tested the feasibility of using a clinical specimen of this medium for the detection of cytologic abnormalities, C. trachomatis, and N. gonorrhoeae; evaluated the agreement between ligase chain reaction (LCR) performed on PreservCyt and LCR performed on a cervical specimen; and compared the performance of LCR performed on PreservCyt to those of LCR performed on a cervical specimen, culture, PCR performed on a cervical specimen, on urine, and on a vaginal specimen (a multiple-site infection status standard), and transcription-mediated amplification (for C. trachomatis only) from 255 sexually active adolescent women. The agreement between LCR performed on PreservCyt and LCR from a cervical swab in LCx transport medium was high (for C. trachomatis, agreement ‫؍‬ 0.97 and kappa ‫؍‬ 0.92; for N. gonorrhoeae, agreement ‫؍‬ 0.99 and kappa ‫؍‬ 0.96). Test performances were similar for LCR-urine, LCR-cervix, and LCR-ThinPrep, with sensitivities from 93 to 99% for C. trachomatis and 81 to 83% for N. gonorrhoeae and specificities from 95.5 to 99% for C. trachomatis and 99.1 to 99.6% for N. gonorrhoeae using a PCR-based multiple-site infection status standard. This is the first study to examine the agreement between liquid cytologic media and multiple nucleic acid amplification tests for the detection of C. trachomatis and N. gonorrhoeae from patient samples. Cytologic fluid shows promise for simultaneous screening for cytologic abnormalities and sexually transmitted infections.

Detection of Chlamydia trachomatis and Neisseria gonorrhoeae Infections in North American Women by Testing SurePath Liquid-Based Pap Specimens in APTIMA Assays

“…Hopwood et al (7), testing CS and ThinPrep samples, showed 100% concordance of 19 LCR positives and 562 negatives, which were stable for 5 months. Koumans et al (9) tested ThinPrep samples from 255 sexually active adolescent women, using LCR for C. trachomatis and N. gonorrhoeae, and also performed other forms of testing on urine and CS samples (LCR for C. trachomatis and N. gonorrhoeae, PCR for C. trachomatis and N. gonorrhoeae, transcription-mediated amplification for C. trachomatis, and culture), which broadened the reference standard for comparison of tests and samples to diagnose infected patients. They reported strong agreement (0.97) for C. trachomatis between LCR on ThinPrep and LCR on CS samples collected into the kit transport medium (kappa, 0.92, where kappa is a statistical measurement of interobserver agreement which compensates and corrects for the proportion of agreement that might be due to chance); for N. gonorrhoeae the agreement was 0.99 (kappa, 0.96).…”

“…There are three liquidbased Pap tests (LPTs) approved by the United States Food and Drug Administration (FDA): PreservCyt ThinPrep (Cytyc, Boxborough, MA), SurePath (TriPath Care Technologies, Burlington, NC), and Cytotek MonoPrep (Monogen, Inc., Vernon Hills, IL). Liquid-based cytology has provided greater Pap testing accuracy, and the sample may serve as a specimen to test for infectious agents, such as human papillomavirus (2,11), Chlamydia trachomatis (5,14), and Neisseria gonorrhoeae (6,9). The APTIMA COMBO 2 assay, APTIMA CT assay for Chlamydia trachomatis, and AP-TIMA GC assay for Neisseria gonorrhoeae are transcriptionmediated amplification tests that utilize target capture specimen processing for the in vitro qualitative detection of rRNA from C. trachomatis and/or N. gonorrhoeae.…”

“…The APTIMA COMBO 2 assay is approved for use with ThinPrep LPT specimens. A limited number of studies have been published using both amplified and nonamplified tests for C. trachomatis or N. gonorrhoeae in liquid-based specimens and have concentrated on the use of ThinPrep samples (1,(5)(6)(7)(8)(9)(10); D. Fuller, T. Davis, and J. Talbott, unpublished data). Our objective was to determine the clinical utility of the APTIMA assays (Gen-Probe Incorporated) for screening women for C. trachomatis and N. gonorrhoeae during their annual Pap examination by using SurePath LPT specimens.…”

Evaluation of the Rapid BioStar Optical Immunoassay for Detection of Chlamydia trachomatis in Adolescent Women

“…The performance of the BioStar Chlamydia OIA was previously evaluated for the detection of C. trachomatis in neonatal conjunctivitis (8) and in urogenital infections of women attending sexually transmitted disease (STD) clinics (6,12). In this study, we evaluated, for the first time, the performance of the BioStar Chlamydia OIA in an inner city adolescent female population (5). Two hundred sixty-one female adolescent patients, 13 to 19 years old, who were enrolled in a larger longitudinal study at a public pediatric clinic in Atlanta, GA, were included in our sample (5).…”

“…Endocervical swab specimens for the BioStar Chlamydia OIA, culture, enzyme immunoassay, and the NAATs were collected by clinicians during the pelvic examination. The BioStar Chlamydia OIA (BioStar, Inc., Boulder, CO) and all of the other diagnostic tests were performed according to the manufacturer's protocol and specifications (5).…”