Aptima CT Research Articles

Point-of-care management of urogenital Chlamydia trachomatis via Gram-stained smear analysis in male high-risk patients. Diagnostic accuracy and cost-effectiveness before and after changing the screening indication at the STI Clinic in Amsterdam

ObjectivesTo measure the effect of changing the point-of-care (POC) testing algorithm of urogenital chlamydia for all male high-risk patients to those with only symptoms with respect to: diagnostic accuracy, loss...

Comparison of the Abbott m 2000 RealTi m e CT Assay and the Cepheid GeneXpert CT/NG Assay to the Roche Amplicor CT Assay for Detection of Chlamydia trachomatis in Ocular Samples from Tanzania

The GeneXpert CT/NG assay (GeneXpert) and the Abbott m2000 RealTime CT (m2000) assay were compared to Amplicor for detecting ocular Chlamydia trachomatis. Discordant specimens were tested by the Aptima CT assay. The m2000 assay sensitivity was 100% (95% confidence interval [CI], 90% to 100%), and specificity was 98.46% (95% CI, 95.2% to 99.2%); GeneXpert sensitivity was 100% (95% CI, 90% to 100%), and specificity was 100% (95% CI, 98.1% to 100%). The m2000 and GeneXpert assays appear to perform as well as the Amplicor assay.

Assessment of best single sample for finding chlamydia in women with and without symptoms: a diagnostic test study

Objective To compare vulvovaginal swabs with endocervical swabs as optimal diagnostic sample for detection of Chlamydia trachomatis infection.Design A diagnostic test study.Setting An urban sexual health centre.Participants 3973 women aged...

P76 Equivocal Aptima Combo 2 results: what do they mean in clinical practice?

BackgroundMolecular diagnostic tests have become standard of care for detection of gonococcal (GC) and chlamydial (CT) infections. The Aptima Combo 2 (AC2) test is widely used and is highly sensitive...

Use of Nucleic Acid Amplification Testing for Diagnosis of Anorectal Sexually Transmitted Infections

Nucleic acid amplification testing (NAAT) has become the preferred method to detect Chlamydia trachomatis and Neisseria gonorrhoeae, but no commercial tests are cleared by the U.S. Food and Drug Administration for use with rectal swab samples. This study evaluated the performance of strand displacement amplification (SDA) and transcription-mediated amplification (TMA) to detect C. trachomatis and N. gonorrhoeae and to determine if TMA could also detect Mycoplasma genitalium and Trichomonas vaginalis in men and women reporting a history of receptive anal intercourse. Discordant results between the NAATs were reevaluated using the Aptima CT or Aptima GC assay, each of which targets primers other than those targeted by the Aptima Combo 2 (AC2) assay, as the confirmatory test. Of 497 evaluable participants, 41 (8.2%) were positive for C. trachomatis, 21 (4.2%) were positive for N. gonorrhoeae, 26 (5.2%) were positive for T. vaginalis, and 47 (9.5%) were positive for M. genitalium. The sensitivity and specificity of the C. trachomatis test were 100% and 99.8% for AC2 and 56.1% and 100% for SDA, respectively. The sensitivity and specificity of the N. gonorrhoeae test were 100% and 100% for AC2 and 76.2% and 100% for SDA, respectively, while culture was only 23.8% sensitive. Of the 114 participants who had a positive result for any of the four infectious agents, 16 were positive for two pathogens and 3 were positive for three pathogens. These data suggest that rectal infection is common and that the AC2 is superior to SDA for the detection of C. trachomatis and N. gonorrhoeae from rectal swab samples.

P3-S1.44 Comparison of self-taken vulvo-vaginal swabs and clinician-taken endocervical swabs using the Gen-Probe Aptima Combo 2 assay vs clinician-taken urethral and endocervical swabs for culture of gonorrhoea

BackgroundThe role of non-invasive testing for gonorrhoea (GC) in women has not yet been fully established in the UK. Validation of NAATs in low prevalence populations has been recommended. Our...

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

The APTIMA COMBO 2 assay, which detects and amplifies rRNA from Chlamydia trachomatis and/or Neisseria gonorrhoeae, is approved for use on ThinPrep liquid-based Pap test specimens. The objective was to determine the clinical utility of the APTIMA assays (APTIMA COMBO 2 assay, APTIMA CT assay for Chlamydia trachomatis, and APTIMA GC assay for Neisseria gonorrhoeae) for screening women during their annual Pap exam, using SurePath liquid-based Pap test specimens. Two cervical samples were collected from 1,615 females attending six clinical sites in North America. A cervical broom sample was processed for cytology, with the residuum aliquoted into an APTIMA specimen transfer kit tube. The second cervical swab sample was put into APTIMA specimen transport medium, and both samples were tested with each APTIMA assay on a direct sampling system. Using a subject-infected status that utilized cervical-swab specimen results from two APTIMA assays, the prevalence was 7.9% for Chlamydia trachomatis and 2.5% for N. gonorrhoeae. For the liquid-based Pap samples, the sensitivities, specificities, positive predictive values, and negative predictive values for Chlamydia trachomatis detection were 85.2%, 99.5%, 93.2%, and 98.7%, respectively, for the APTIMA COMBO 2 assay and 89.1%, 98.7%, 85.7%, and 99.1%, respectively, for the APTIMA CT assay. For N. gonorrhoeae detection, the values were 92.5%, 100%, 100%, and 99.8%, respectively, for the APTIMA COMBO 2 assay and 92.5%, 99.9%, 97.4%, and 99.8%, respectively, for the APTIMA GC assay. The high predictive values support the use of the assays with SurePath liquid-based Pap specimens processed with the APTIMA specimen transfer kit.

Ability of New APTIMA CT and APTIMA GC Assays To Detect Chlamydia trachomatis and Neisseria gonorrhoeae in Male Urine and Urethral Swabs

A clinical evaluation was conducted in six North American centers to determine the ability of APTIMA CT (ACT) and APTIMA GC (AGC) nucleic acid amplification assays to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections in 1,322 men by testing their urethral swabs and first-catch urine (FCU). The results obtained with ACT and AGC assays were compared to an infected patient status determined by testing the specimens with the APTIMA Combo 2 and the BD ProbeTec energy transfer multiplex assays. Symptoms did not influence the values. Positive and negative agreements of the ACT and AGC assays for individual specimens were high, with each comparator assay ranging between 94.3 and 100% for positives and 93.9 and 99.4% for negatives. The ACT and AGC assays performed on noninvasive specimens such as FCU effectively identified C. trachomatis or N. gonorrhoeae infections in symptomatic and asymptomatic men and should be suitable for screening male populations.

Tabetic gastric crisis with fluid levels and visible peristalsis.

<h3>Introduction</h3> Both women and men who have sex with men (MSM) report frequent receptive oral sex, but there are no FDA approved tests for detection of <i>Neisseria gonorrhoeae</i> (GC) and <i>Chlamydia trachomatis</i> (CT) from pharyngeal swabs. The objective of this study was to evaluate the number of pharyngeal GC and CT infections, and to assess the sensitivity of GC culture. <h3>Methods</h3> Women (n = 172) and MSM (n = 222) reporting a lifetime history of both receptive oral and anal sex completed a structured questionnaire and clinicians collected swab samples from the pharynx and anorectum. Vaginal swabs were obtained from women and urine samples from men. Testing for CT and GC was performed using Cepheid Xpert CT/NG (Xpert) and Gen-Probe Aptima (AC2). True positives were defined if both AC2 and Xpert were positive, if GC culture was positive, or if either AC2 or Xpert were positive and confirmatory tests APTIMA CT or APTIMA GC were positive. <h3>Results</h3> Identification of GC and/or CT at any site (pharyngeal, rectal or genitourinary) occurred in 78/222 (35%) males and 25/172 (14.5%) of females. Only 8 (2%) of pharyngeal swab samples were positive for CT, while 4 women (2.3%) and 37 (16.7%) men tested positive for pharyngeal GC based on NAAT. GC culture of the pharynx was performed for 373 of participants in the study, and was positive in 13 (3.5%), for a &nbsp;sensitivity of 32% for culture vs NAAT. Overall, 17/55 (31%) of the total GC infections in men would have been missed without NAAT pharyngeal testing. <h3>Conclusion</h3> Men who report a lifetime history of receptive oral intercourse have high rates of pharyngeal GC, most of which will remain undetected unless NAAT is used. The frequency of pharyngeal infection due to CT is low even among people having high overall rates of infection. <h3>Disclosure of interest</h3> Reagents for CT/GC testing were provided for by Cepheid and Hologic.