(128 days)
The Cepheid Xpert TV Assay, performed on the GeneXpert® Instrument Systems, is a qualitative in vitro diagnostic test for the detection of Trichomonas vaginalis genomic DNA. The test utilizes automated real-time polymerase chain reaction (PCR) to detect Trichomonas vaginalis genomic DNA. The Xpert TV Assay uses female urine specimens, endocervical swab specimens, or patient-collected vaginal swab specimens (collected in a clinical setting). The Xpert TV Assay is intended to aid in the diagnosis of trichomoniasis in symptomatic or asymptomatic individuals.
Ancillary Collection Kits:
Xpert Vaginal/Endocervical Specimen Collection Kit
The Cepheid® Xpert® Vaginal/Endocervical Specimen Collection Kit is designed to collect, preserve, and transport Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis DNA in endocervical swab specimens (collected by a clinician) and patient-collected vaginal swab specimens (collected in a clinical setting) from symptomatic and asymptomatic women prior to analysis with the Xpert CT/NG Assay and the Xpert TV Assay.
Xpert Urine Specimen Collection Kit
The Cepheid® Xpert® Urine Specimen Collection Kit is designed to preserve and transport Chlamydia trachomatis, Neisseria gonorthoeae, and Trichomonas vaginalis DNA in first-catch urine specimens from symptomatic and asymptomatic individuals prior to analysis with the Xpert CT/NG Assay and the Xpert TV Assay. The Xpert Urine Specimen Collection Kit is intended for use with male (Xpert CT/NG Assay) and female (Xpert CT/NG Assay and Xpert TV Assay) urine.
The Xpert TV Assay is an automated real-time polymerase chain reaction (PCR) in vitro diagnostic test for qualitative detection of genomic DNA from Trichomonas vaginalis. The Xpert TV Assay is intended as an aid in the diagnosis of trichomoniasis.
The Xpert TV Assay is performed on the Cepheid GeneXpert® Instrument Systems (GeneXpert Dx., GeneXpert Infinity-48, GeneXpert Infinity-48s, and GeneXpert Infinity-80 systems). The GeneXpert Instrument System platform automates sample preparation, amplification and real-time detection.
The GeneXpert Instrument Systems require the use of single-use, disposable cartridges (the Xpert TV cartridges) that hold the PCR reagents and host the PCR process. Because the cartridges are self-contained and specimens never come into contact with working parts of the instrument modules, cross-contamination between samples is minimized.
The Xpert TV Assay cartridges contain reagents for the detection of genomic DNA from T. vaginalis for use with the following specimens collected from symptomatic and asymptomatic individuals: female urine, endocervical swab and patient-collected vaginal swab (collected in a clinical setting). A Sample Processing Control (SPC). Sample Adequacy Control (SAC), and a Probe Check Control (PCC) are controls utilized by the GeneXpert Instrument System platform. The SPC, SAC, and PCC are controls utilized by the GeneXpert Instrument System platform. The SPC is present to control for adequate processing of the target trichomonads and to monitor the presence of inhibitors in the real-time PCR reaction to reduce the possibility of false negative results. The SAC reagents detect the presence of a single copy human gene and monitor whether the specimen contains human cells. The PCC verifies reagent rehydration, real-time PCR tube filling in the cartridge, probe integrity, and dye stability.
The single-use, multi-chambered fluidic cartridges are designed to complete sample preparation and real-time PCR for the detection of genomic DNA from T. vaginalis in 70 minutes or less. The GeneXpert Instrument Systems, comprised of the GeneXpert Dx Systems and the GeneXpert Infinity Systems, have 1 to 80 randomly accessible modules, depending upon the instrument, that are each capable of performing separate sample preparation and real-time PCR and RT-PCR tests. Each module contains a syringe drive for dispensing fluids (i.e., the syringe drive activates the plunger that works in concert with the rotary valve in the cartridge to move fluids between chambers), an ultrasonic horn for lysing cells or spores', and a proprietary I-CORE® thermocycler for performing real-time PCR and RT-PCR and detection.
The swab and/or urine specimens are collected from asymptomatic or symptomatic patients and placed into a specimen transport tube containing preservative. The specimen is transferred to the sample chamber of the disposable fluidic cartridge (the Xpert TV cartridge). The user initiates a test from the system user interface and places the cartridge into the GeneXpert instrument platform, which performs hands-off real-time, multiplex PCR for detection of DNA. The results are automatically generated at the end of the process in a report that can be viewed and printed.
The ancillary specimen collection kits for use with the Xpert TV Assay are the Cepheid Xpert Vaginal/Endocervical Specimen Collection Kit and the Cepheid Xpert Urine Specimen Collection Kit.
Here's an analysis of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Device: Xpert® TV Assay on the Cepheid GeneXpert Instrument Systems
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state "acceptance criteria" for clinical performance in a pass/fail format. Instead, it presents the clinical performance results and implies that these values are acceptable by concluding substantial equivalence. For the analytical studies, the implied criteria are 95% confidence for LoD and no interference/cross-reactivity for analytical specificity and interfering substances (except for noted limitations).
| Acceptance Criteria Category | Specific Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Clinical Performance | Sensitivity (relative to PIS): High percentage, demonstrating ability to detect true positives. | Endocervical Swabs (Overall): 98.9% (175/177) |
| Patient-Collected Vaginal Swabs (Overall): 96.4% (186/193) | ||
| Female Urine (Overall): 98.4% (180/183) | ||
| Specificity (relative to PIS): High percentage, demonstrating ability to correctly identify true negatives. | Endocervical Swabs (Overall): 98.9% (1604/1622) | |
| Patient-Collected Vaginal Swabs (Overall): 99.6% (1591/1598) | ||
| Female Urine (Overall): 99.7% (1605/1610) | ||
| Valid Reporting Rate: High percentage of valid results. | 99.9% (5383/5391) | |
| Analytical Sensitivity (LoD) | Ability to detect T. vaginalis at low concentrations with 95% confidence. | T. vaginalis ATCC 30001 (Vaginal Swab): 2 cells/mL |
| T. vaginalis ATCC 30238 (Vaginal Swab): 2 cells/mL | ||
| T. vaginalis ATCC 30001 (Urine): 3 cells/mL | ||
| T. vaginalis ATCC 30238 (Urine): 2 cells/mL | ||
| Analytical Specificity (Cross-Reactivity) | No false positives from a panel of common urogenital microorganisms. | Out of 124 microorganisms tested, Trichomonas tenax demonstrated cross-reactivity at 1 x 105 cells/mL and 1 x 103 cells/mL, but not at 1 x 102 cells/mL. All other 123 microorganisms showed no cross-reactivity (TV NOT DETECTED in absence of TV) or competitive interference (TV DETECTED in presence of TV). (This is noted as a limitation in the package insert). In silico analysis for Dientamoeba fragilis, Agrobacterium radiobacter, and Erwinia herbicola showed low homology (max 38%). |
| Analytical Specificity (Competitive Interference) | No false negatives from a panel of common urogenital microorganisms in the presence of T. vaginalis. | All microorganisms (except T. tenax as detailed above) did not interfere with T. vaginalis detection. |
| Interfering Substances | No false negatives or false positives from common endogenous and exogenous substances. | Blood at >60% v/v demonstrated interference (false negative) in vaginal swab samples; no interference at 50% v/v. All other substances (including various analgesics, antibiotics, OTC products, biological fluid components) showed no interference. (This is noted as a limitation in the package insert). |
| Analytical Reactivity (Inclusivity) | 100% detection of diverse T. vaginalis strains. | 100% detection (TV DETECTED) for 17 diverse T. vaginalis strains tested. |
| Carry-Over Contamination | No carry-over contamination between high positive and negative samples. | All 40 positive samples correctly reported as TV DETECTED, and all 42 negative samples correctly reported as TV NOT DETECTED. No evidence of carry-over contamination. |
| Reproducibility | Consistent results across sites, operators, and days for different concentration levels. | Agreement rates for expected results were generally high for negative and moderate positive samples (100%). For LoD and High Neg samples, agreement varied but was still substantial (e.g., FS-LoD: 95.8%, UR-LoD: 88.8%, FS-High Neg: 76.4%, UR-High Neg: 70.8%). Ct value variability (CV%) due to various factors (site, lot, day, operator, residual) was low, generally =99%). For LoD and High Neg samples, agreement was substantial (e.g., FS-LoD: 91.7%, UR-LoD: 94.1%, FS-High Neg: 75.6%, UR-High Neg: 77.8%). Ct value variability was low, generally |
§ 866.3860
Trichomonas vaginalis nucleic acid assay.(a)
Identification. ATrichomonas vaginalis nucleic acid assay is a device that consists of primers, probes, enzymes, and controls for the amplification and detection of trichomonas nucleic acids in endocervical swabs, vaginal swabs, and female urine specimens, from women symptomatic for vaginitis, cervicitis, or urethritis and/or to aid in the diagnosis of trichomoniasis in asymptomatic women. The detection of trichomonas nucleic acids, in conjunction with other laboratory tests, aids in the clinical laboratory diagnosis of trichomoniasis caused byTrichomonas vaginalis .(b)
Classification. Class II (special controls). The special controls are set forth in FDA's guideline document entitled: “Class II Special Controls Guideline: Nucleic Acid Amplification Assays for the Detection ofTrichomonas vaginalis; Guideline for Industry and Food and Drug Administration Staff.” See § 866.1(e) for information on obtaining this document.