(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 <5% total for positive controls. |
| Instrument System Precision | Consistent results across different GeneXpert Instrument Systems. | Similar to reproducibility, agreement rates for expected results were high for negative and moderate positive samples (>=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 <4% total for positive controls. |
2. Sample Size Used for the Test Set and Data Provenance:
- Clinical Study Test Set Sample Size:
- Endocervical Swabs (ES): 1799
- Patient-Collected Vaginal Swabs (PC-VS): 1791
- Female Urine (UR): 1793
- Total unique participants: 1867 females (from which 5391 tests were performed across the three specimen types).
- Data Provenance:
- Country of Origin: United States (17 collection sites in the US).
- Retrospective or Prospective: Prospective investigational study.
- Study Population: Asymptomatic and symptomatic, sexually active females (18 to 78 years old), seen at OB/GYN, STD, and family planning clinics.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
The document does not specify the number of experts or their qualifications for establishing the ground truth (PIS). The PIS was established using an algorithm based on an FDA-cleared NAAT test and culture, and reference testing was performed at 3 central laboratories. It does not mention expert review of these results for ground truth.
4. Adjudication Method for the Test Set:
The ground truth for the clinical performance study (Patient Infected Status, PIS) was established using an algorithm:
- A study participant was considered infected by PIS if either of the reference tests (FDA cleared NAAT and culture) results were positive.
- The subject was considered not infected by PIS when both reference test results were negative.
Specimens with discrepant results between the Xpert TV Assay and the PIS were analyzed by validated bi-directional Sanger sequencing for informational purposes only. This sequencing was not part of the initial PIS establishment but was used for further investigation of discrepancies.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was Done, If so, What was the Effect Size of How Much Human Readers Improve with AI vs without AI Assistance:
This information is not applicable. The study describes the performance of an in vitro diagnostic (IVD) assay (nucleic acid amplification test) for detecting Trichomonas vaginalis. This is a laboratory test that generates a qualitative (DETECTED/NOT DETECTED) result, not an AI imaging device involving human readers or interpretation of complex medical images. Therefore, the concept of human readers improving with AI assistance is not relevant to this type of device or study.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) was Done:
Yes, a standalone performance study was done. The Xpert TV Assay is described as an "automated real-time polymerase chain reaction (PCR) in vitro diagnostic test" performed on "GeneXpert® Instrument Systems" which "automates sample preparation, amplification and real-time detection." The results are "automatically generated at the end of the process in a report." While a human operator initiates the test and places the cartridge, the diagnostic result itself is produced by the automated system without human interpretation. The clinical performance data presented (sensitivity, specificity, etc.) are for the standalone device against the PIS.
7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.):
The ground truth used was a "patient infected status (PIS) algorithm comprised of an FDA cleared NAAT test and culture." This is a composite reference standard using two established laboratory diagnostic methods.
8. The Sample Size for the Training Set:
The document does not explicitly describe a training set sample size or a distinct training process for the Xpert TV Assay in the context of machine learning or AI. For IVD assays, development involves method optimization and analytical studies. The clinical study described is a validation study to demonstrate performance against a established standard (PIS), which is typically equivalent to a test set for a diagnostic device.
9. How the Ground Truth for the Training Set Was Established:
As there is no explicitly mentioned "training set" in the context of evolving AI algorithms, this question is not directly applicable from the provided text for the Xpert TV Assay. The assay's "ground truth" (PIS) for its validation (clinical study) was established as described in section 4. Development of the assay itself would have involved laboratory experiments and optimization protocols to ensure it accurately targets and amplifies T. vaginalis DNA.
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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002
October 16, 2015
Cepheid Scott Campbell, Ph.D., MBA Vice President, Clinical Affairs 904 Caribbean Drive Sunnyvale, CA 94089-1189
Re: K151565
Trade/Device Name: Xpert® TV Assay on the Cepheid GeneXpert Instrument Systems (GeneXpert Dx, GeneXpert Infinity-48, GeneXpert Infinity-48s, and GeneXpertInfinity-80 systems).
Xpert Vaginal/Endocervical Specimen Collection Kit, and Xpert Urine Specimen Collection Kit
Regulation Number: 21 CFR 866.3860 Regulation Name: Trichomonas vaginalis nucleic acid assay Regulatory Class: II Product Code: OUY, OOI Dated: September 11, 2015 Received: September 14, 2015
Dear Dr. Campbell:
We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements
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as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to
http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.
You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address
http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.
Sincerely yours,
Tamara V. Feldblyum -S for
Uwe Scherf, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health
Enclosure
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Indications for Use
510(k) Number (if known) K151565
Device Name Xpert® TV
Indications for Use (Describe)
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.
| Type of Use (Select one or both, as applicable) | |
|---|---|
| Prescription Use (Part 21 CFR 801 Subpart D) | Over-The-Counter Use (21 CFR 801 Subpart C) |
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510(k) Summary
As required by 21 CFR Section 807.92(c).
| Submitted by: | Cepheid904 Caribbean DriveSunnyvale, CA 90489Phone number: (847) 228-3299Fax number: (847) 593-0233 |
|---|---|
| Contact: | Scott A. Campbell, Ph.D, MBA |
| Date of Preparation: | October 12, 2015 |
| Device: | |
| Trade name: | Xpert® TV |
| Common name: | Xpert TV Assay |
| Type of Test: | Real-Time Polymerase Chain Reaction (PCR) for the detectionof Trichomonas vaginalis |
| Regulation number/Classification name/Product code: | 866.3860/ Trichomonas vaginalis nucleic acid amplification testsystem /OUY862.2570/Instrumentation for clinical multiplex testsystems/OOI |
| ClassificationAdvisory Panel | Microbiology (83) |
| Prescription Use | Yes |
| Predicate DeviceAssay: | Gen-Probe® Aptima Trichomonas vaginalis Assay[510(k) #K122062] |
| Predicate DeviceAssay: | Xpert CT/NG Vaginal/Endocervical Specimen Collection Kit[510(k) #K121710]Xpert CT/NG Urine Specimen Collection Kit[510(k) #K121710] |
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Device Description:
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
1 Although sonication is a fundamental capability of every GeneXpert module, sonication is not used in the Xpert TV Assay.
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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.
Device Intended Use:
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 gonorrhoeae, 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.
Substantial Equivalence:
The Xpert TV Assay is substantially equivalent to the Gen-Probe® Aptima Trichomonas vaginalis Assay [510(k) # K122062]. The Xpert TV Assay and the Gen-Probe Aptima Trichomonas vaginalis Assay both detect T. vaginalis from endocervical swab, patientcollected vaginal swab (collected in a clinical setting), and female urine specimens using nucleic acid-based technology. The performance of the Xpert TV Assay was evaluated in a multi-site clinical study in which the performance of the Xpert TV Assay was compared to a patient-infected status (PIS). The results of the study demonstrated that the performance of the Xpert TV Assay is substantially equivalent to the predicate device.
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Table 5-1 shows the similarities and differences between the Xpert TV Assay and the predicate device.
| Similarities | ||
|---|---|---|
| Item | Device | Predicate Device |
| Cepheid Xpert TV Assay | Gen-Probe AptimaTrichomonas vaginalisAssay | |
| 510(k) Number | K151565 | K122062 |
| Regulation | 866.3860 | 866.3860 |
| Product Code | OUY | OUY |
| Device Class | Same | II |
| Intended Use | The Cepheid Xpert TV Assay,performed on the GeneXpert®Instrument Systems, is aqualitative in vitro diagnostictest for the detection ofTrichomonas vaginalisgenomic DNA. The testutilizes automated real-timepolymerase chain reaction(PCR) to detect Trichomonasvaginalis genomic DNA. TheXpert TV Assay uses femaleurine specimens, endocervicalswab specimens, or patient-collected vaginal swabspecimens (collected in aclinical setting). The Xpert TVAssay is intended to aid in thediagnosis of trichomoniasis insymptomatic or asymptomaticindividuals.Ancillary Collection Kits:Xpert Vaginal/EndocervicalSpecimen Collection KitThe Cepheid® Xpert® | The APTIMA Trichomonasvaginalis Assay is an in vitroqualitative nucleic acidamplification test (NAAT) forthe detection of ribosomalRNA (rRNA) fromTrichomonas vaginalis to aidin the diagnosis oftrichomoniasis using theTIGRIS DTS System. Theassay may be used to test thefollowing specimens fromsymptomatic or asymptomaticwomen: clinician-collectedendocervical swabs, clinician-collected vaginal swabs,female urine specimens, andspecimens collected inPreservCyt Solution. |
| Similarities | ||
| Item | Device | Predicate Device |
| Cepheid Xpert TV Assay | Gen-Probe AptimaTrichomonas vaginalisAssay | |
| Vaginal/EndocervicalSpecimen Collection Kit isdesigned to collect, preserve,and transport Chlamydiatrachomatis, Neisseriagonorrhoeae, andTrichomonas vaginalis DNAin endocervical swabspecimens (collected by aclinician) and patient-collectedvaginal swab specimens(collected in a clinical setting)from symptomatic andasymptomatic women prior toanalysis with the Xpert CT/NGAssay and the Xpert TVAssay.Xpert Urine SpecimenCollection KitThe Cepheid® Xpert® UrineSpecimen Collection Kit isdesigned to preserve andtransport Chlamydiatrachomatis, Neisseriagonorrhoeae, andTrichomonas vaginalis DNAin first-catch urine specimensfrom symptomatic andasymptomatic individuals priorto analysis with the XpertCT/NG Assay and the XpertTV Assay. The Xpert UrineSpecimen Collection Kit isintended for use with male(Xpert CT/NG Assay) andfemale (Xpert CT/NG Assayand Xpert TV Assay) urine. | ||
| Assay Targets | T. vaginalis genomic DNA | T. vaginalis ribosomal RNA |
| Similarities | ||
| Item | Device | Predicate Device |
| Cepheid Xpert TV Assay | Gen-Probe AptimaTrichomonas vaginalisAssay | |
| Specimen Types | Endocervical SwabsVaginal SwabsFemale Urine | Endocervical SwabsVaginal SwabsFemale Urine |
| Nucleic AcidExtraction | Yes | Yes |
| Assay Results | Same | Qualitative |
| Collection Kit | Same | Urine collection kitSwab collection kit |
Table 5-1: Comparison of Similarities and Differences of the Xpert TV Assay with the Predicate Device
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| Primary Differences | |||
|---|---|---|---|
| New Device | Predicate Device | ||
| Item | Cepheid Xpert TV Assay | Gen-Probe AptimaTrichomonas vaginalis Assay | |
| Technology/Detection | Multiplex real-timepolymerase chain reaction(PCR) | Transcription-mediatedamplification (TMA) | |
| Specimen Types | Endocervical SwabsVaginal SwabsFemale Urine | Endocervical SwabsVaginal SwabsFemale Urine | |
| Instrument System | Cepheid GeneXpertInstrument System | TIGRIS DTS System | |
| Laboratory Users | Operators in Moderate andHigh Complexity labs | CLIA High Complexity | |
| Early assaytermination function | Yes(for positive samples) | No |
The Xpert TV Assay has the same general intended use as the predicate device and has the same technological characteristics as the predicate device. The differences between the Xpert TV Assay and the predicate device do not raise different questions of safety and effectiveness. The clinical study demonstrates that the Xpert TV Assay is acceptable
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for its intended use with inexperienced lab users and is substantially equivalent to the predicate device described above.
Ancillary Collection Kits:
Xpert Vaginal/Endocervical Specimen Collection Kit and Xpert Urine Specimen Collection Kit
The predicate devices for the ancillary specimen collection kits, the Cepheid Xpert® Vaginal/Endocervical Specimen Collection Kit and Cepheid Xpert Urine Specimen Collection Kit, are the Cepheid Xpert CT/NG Vaginal/Endocervical Specimen Collection Kit and the Cepheid Xpert CT/NG Urine Specimen Collection Kit [510(k) #K121710]. The similarities and differences are shown in Tables 5-2 and 5-3.
| Similarities | ||
|---|---|---|
| Device | Predicate | |
| Item | Cepheid XpertVaginal/EndocervicalSpecimen Collection Kit | Cepheid Xpert CT/NGVaginal/EndocervicalSpecimen Collection Kit |
| Intended Use(Similarities) | Same | The collection kit is used forthe collection of endocervicalswab specimens (collected by aclinician) and patient-collectedvaginal swab specimens(collected in a clinical setting)and is designed to collect,preserve and transport patientChlamydia trachomatis andNeisseria gonorrhoeae DNA inendocervical and vaginalspecimens. |
| Single-use Device | Yes | Yes |
| Transport MediumpH | Same | 8.15-8.55 |
Table 5-2: Comparison of Similarities and Differences of the Xpert Vaginal/Endocervical Specimen Collection Kit with the Predicate Device
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| Similarities | ||
|---|---|---|
| Device | Predicate | |
| Item | Cepheid XpertVaginal/EndocervicalSpecimen Collection Kit | Cepheid Xpert CT/NGVaginal/EndocervicalSpecimen Collection Kit |
| Description | Same | Contains an individuallypackaged sterile large cleaningswab (for endocervicalsamples) and a packagecontaining an individuallypackaged sterile collectionswab (for vaginal andendocervical sampling) and aswab transport reagent tube.The collection swab is placedinto the transport reagent tubeafter swab sampling to stabilizethe nucleic acid until samplepreparation. |
{11}------------------------------------------------
| Differences | ||
|---|---|---|
| Item | Device | Predicate |
| Intended Use(differences) | Specimen storageand transport when testing forthe presence of Chlamydiatrachomatis , Neisseriagonorrhoeae , andTrichomonas vaginalis invaginal and endocervical swabspecimens. | Specimen storageand transport when testing forthe presence of Chlamydiatrachomatis and Neisseriagonorrhoeae in vaginal andendocervical swab specimens. |
| Table 5-3: Comparison of Similarities and Differences of the Xpert Urine Specimen |
|---|
| Collection Kit with the Predicate Device |
| Similarities | ||
|---|---|---|
| Device | Predicate | |
| Item | Cepheid Xpert UrineSpecimen Collection Kit | Cepheid Xpert CT/NG UrineSpecimen Collection Kit |
| Intended Use(Similarities) | The collection kit is designed topreserve and transportChlamydia trachomatis andNeisseria gonorrhoeae DNA infirst-catch female urinespecimens from symptomaticand asymptomatic individualsprior to analysis. | The collection kit is designedto preserve and transportChlamydia trachomatis andNeisseria gonorrhoeae DNAin first-catch male and femaleurine specimens fromsymptomatic andasymptomatic individualsprior to analysis. |
| Single-use Device | Yes | Yes |
| Transport MediumpH | Same | 7.95 – 8.35 |
| Description | Same | Contains one individuallypackaged sterile disposabletransfer pipette and one urinetransport reagent tube.Approximately 7 mL of afirst-catch urine specimen istransferred to the UrineTransport Reagent tube topreserve and transport thespecimen prior to analysiswith the assay. |
{12}------------------------------------------------
| Similarities | ||
|---|---|---|
| Item | Device | Predicate |
| Cepheid Xpert UrineSpecimen Collection Kit | Cepheid Xpert CT/NG UrineSpecimen Collection Kit | |
| Differences | ||
| Item | Device | Predicate |
| Intended Use(differences) | Specimen storage and transportwhen testing for the presence ofChlamydia trachomatis,Neisseria gonorrhoeae, andTrichomonas vaginalis in urinespecimens. | Specimen storage and transportwhen testing for the presence ofChlamydia trachomatis andNeisseria gonorrhoeae in urinespecimens. |
Non-Clinical Studies:
Analytical Sensitivity (Limit of Detection)
The analytical sensitivity or limit of detection (LoD) of the Xpert TV Assay was assessed using two Trichomonas vaginalis strains, one metronidazole susceptible (T. vaginalis ATCC® 30001™), and one metronidazole resistant (T. vaginalis ATCC® 30238™). Both strains were tested individually in clinical T. vaginalis-negative pooled urine matrix in Cepheid Xpert Urine Transport Reagent and clinical T. vaginalisnegative pooled vaginal swab matrix (VS) in Cepheid Xpert Swab Transport Reagent.
T. vaginalis was cultured and incubated at 35°C. Visual examination of the cultures for white precipitate (indicating growth) was conducted every 24 hours for 3 to 5 days. Cell pellets were resuspended in growth medium and enumerated visually using light microscopy. The concentration of isolates was expressed as the number of cells per milliliter (cells/mL). Cultures were diluted in culture medium to 1 x 10 cells/mL and stored at -20°C. Cells were thawed on ice for use in the study.
The limit of detection (LoD) was estimated by testing replicates of 20 at five concentrations for each strain and sample type over three days. The LoD for each strain was estimated by probit analysis. The claimed LoDs were confirmed by analyzing at least 20 replicates with T. vaginalis cells diluted to the estimated LoD concentrations. The LoD is defined as the lowest number of cells/mL that can be reproducibly distinguished from negative samples with 95% confidence or the lowest concentration at which 19 of 20 replicates were positive. The study was performed with two different lots of Xpert TV reagents and the claimed LoD for each strain is the higher of the two determinations (Table 5-4). The claimed LoD for T. vaginalis strains ATCC 30001 and ATCC 30238 in vaginal swab matrix is 2 cells/mL. The claimed LoD for T. vaginalis strain ATCC 30001 in urine matrix is 3 cells/mL. The claimed LoD for T. vaginalis strain ATCC 30238 in urine matrix is 2 cells/mL.
{13}------------------------------------------------
The LoD point estimates and confirmed LoD for each genogroup tested are summarized in Table 5-4.
| Trichomonasvaginalis | LoD Estimates byProbit Analysis(cells/mL) | VerifiedLoD | Verification(Positives/20) | Mean TVCt | Mean SACCt | Mean SPCCt | LoDClaim | |
|---|---|---|---|---|---|---|---|---|
| strain and matrix | ReagentLot 1 | ReagentLot 2 | (cells/mL) | (cells/mL) | ||||
| ATCC 30001 inVaginal Swab | 2.0 | 1.6 | 2.0 | 20/20 | 39.1 | 21.4 | 33.9 | 2 |
| ATCC 30238 inVaginal Swab | 1.7 | 2.1 | 2.1 | 20/20 | 37.5 | 21.4 | 33.7 | 2 |
| ATCC 30001 inUrine | 2.2 | 2.5 | 2.5 | 20/20 | 38.2 | 29.3 | 34.1 | 3 |
| ATCC 30238 inUrine | 2.1 | 1.7 | 2.1 | 20/20 | 38.2 | 29.2 | 33.8 | 2 |
Table 5-4: LoD of Two T. vaginalis Strains in Pooled Vaginal Swab Matrix and Urine Matrix
Analytical Specificity (Cross-reactivity and Competitive Interference)
A panel of 124 microorganisms, including bacteria, fungi, and viruses commonly found in the urogenital tract, as well as other protozoans closely related to T. vaginalis were tested with the Xpert TV Assay. The microorganisms were tested in the presence (competitive interference) and absence (cross-reactivity) of 3X LoD T. vaginalis ATCC 30001 cells. The microorganisms were seeded into either pooled Trichomonas vaginalis-negative urine matrix (patient urine added to Cepheid Urine Transport Reagent) or pooled Trichomonas vaginalis-negative vaginal swab matrix (vaginal swabs collected into Cepheid Swab Transport Reagent).
Each bacterial or fungal strain was tested at 1 x 106 CFU/mL or greater or at 1 x 10° genomes/mL. Viral strains were tested at 1 x 105 U/mL or 105 genomes/mL or greater. Protozoans were cultured in growth media, visually enumerated by light microscopy and tested at 1 x 105 cells/mL or greater or 106 genomes/mL. All microorganisms were tested in triplicate. Positive and negative controls were included in the study. One organism, Trichomonas tenax, demonstrated cross-reactivity (result of TV DETECTED in the absence of TV) at 1 x 10 cells/mL for the urine and vaginal swab matrix samples. Trichomonas tenax was subjected to repeat analysis at various other concentrations until a result of TV NOT DETECTED was obtained (at 1 x 102 cells/mL). This is addressed in Limitations in the package insert. For the other 123 microorganisms, all TV positive samples remained positive and all TV negative samples remained negative, indicating that there was no interference or cross-reactivity with the results of the Xpert TV Assay for these microorganisms. Results are shown in Table 5-5 and Table 5-6 for urine and vaginal swab matrix, respectively.
{14}------------------------------------------------
| Microorganism | ConcentrationTesteda | Xpert TV Assay Result | ||||||
|---|---|---|---|---|---|---|---|---|
| Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |||||||
| Achromobacter xerosis | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Acinetobacter calcoaceticus | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Acinetobacter lwoffii | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Actinomyces israeliib | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Actinomyces pyogenes | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Aerococcus viridans | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Aeromonas hydrophila | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Alcaligenes faecalis | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Atopobium vaginaeb | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Bacillus subtilis | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Bacteroides fragilisb | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Bacteroides ureolyticusb | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Bifidobacterium adolescentisb | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Bifidobacterium brevi (breve)b | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Blastocystis hominisc | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Branhamella catarrhalis | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Brevibacterium linens | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Campylobacter jejuni | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Candida albicanse | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida glabratae | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida parapsilosie | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida tropicalise | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Chlamydia trachomatis | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Chromobacterium violaceum | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Citrobacter freundii | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Clostridium difficileb | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Clostridium perfringensb | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Corynebacterium genitalium | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Corynebacterium xerosis | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Cryptococcus neoformanse | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Microorganism | ConcentrationTesteda | Xpert TV Assay Result | ||||||
| Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |||||||
| Cryptosporidium parvumc | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Cytomegalovirusf | 5 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Deinococcus radiodurans | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Derxia gummosa | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Eikenella corrodens | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Entamoeba histolyticae | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Enterobacter aerogenes | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Enterobacter cloacae | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Enterococcus avium | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Enterococcus faecalis | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Enterococcus faecium | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Erysipelothrix rhusiopathiae | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Escherichia coli | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Flavobacterium meningosepticum | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Fusobacterium nucleatumb | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Gardnerella vaginalis | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Gemella haemolysans | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Giardia intestinalisc | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Haemophilus ducreyi | 1 x 105d | TV NOT DETECTED | TV DETECTED | |||||
| Haemophilus influenzae | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Herpes simplex virus If | 1 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Herpes simplex virus IIf | 1 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| HIV-1f | 2 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Human papilloma virus 16f | 6 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Kingella dentrificans | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Kingella kingae | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Klebsiella oxytoca | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Klebsiella pneumoniae | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Lactobacillus acidophilus | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Lactobacillus brevis | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Lactobacillus crispatus | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Lactobacillus jensonii | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Microorganism | ConcentrationTesteda | Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |||||
| Lactobacillus lactis | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Lactobacillus vaginalis | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Legionella pneumophila | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Leuconostoc paramensenteroides | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Listeria monocytogenes | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Micrococcus luteus | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Mobiluncus curtisiib | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Moraxella lacunata | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Moraxella osloensis | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Morganella morganii | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Mycobacterium smegmatis | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Mycoplasma genitalium | 1 x 106d | TV NOT DETECTED | TV DETECTED | |||||
| Mycoplasma hominis | 1 x 106d | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria cinerea | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria dentrificans | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria elongata | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria flava | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria flavescens | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria gonorrhoeae | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria lactamica | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria mucosa | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria perflava | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria polysaccharea | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria sicca | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Neisseria subflava | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Pantoea agglomerans | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Paracoccus denitrificans | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Pentatrichomonis hominisc | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Peptostreptococcus anaerobiusb | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Peptostreptococcus productusb | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Plesiomonas shigelloides | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Prevotella biviab | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Microorganism | ConcentrationTesteda | Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |||||
| Propionibacterium acnesb | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Proteus mirabilis | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Proteus vulgaris | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Providencia stuartii | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Pseudomonas aeruginosa | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Pseudomonas fluorescens | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Pseudomonas putida | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Rahnella aquatilis | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Rhodospirillum rubrum | 1 x 106d | TV NOT DETECTED | TV DETECTED | |||||
| Saccharomyces cerevisiaee | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Salmonella minnesota | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Salmonella typhimurium | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Serratia marcescens | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Staphylococcus aureus | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Staphylococcus epidermidis | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Staphylococcus saprophyticus | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus agalactiae | 1 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus bovis | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus mitis | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus mutans | 2 x 107 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus pneumoniae | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus pyogenes | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus salivarius | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptococcus sanguis | 5 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Streptomyces griseinus | 6 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Trichomonas tenaxc | 1 x 105 | TV DETECTED | TV DETECTED | |||||
| Trichomonas tenaxc | 1 x 103 | TV DETECTED | TV DETECTED | |||||
| Trichomonas tenaxc | 1 x 102 | TV NOT DETECTED | TV DETECTED | |||||
| Ureaplasma parvum | 1 x 106d | TV NOT DETECTED | TV DETECTED | |||||
| Ureaplasma urealyticum | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Vibrio parahaemolyticus | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Yersinia enterocolitica | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Xpert TV Assay in Vaginal Swab Matrix | ||||||||
| Microorganism | ConcentrationTesteda | Xpert TV Assay Result Cross-Reactivity(- T. vaginalis) CompetitiveInterference(+ T. vaginalis) | ||||||
| Achromobacter xerosis | 1 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Acinetobacter calcoaceticus | 3 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Acinetobacter lwoffii | 6 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Actinomyces israeliib | 2 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Actinomyces pyogenes | 8 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Aerococcus viridans | 5 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Aeromonas hydrophila | 5 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Alcaligenes faecalis | 5 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Atopobium vaginaeb | 2 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Bacillus subtilis | 6 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Bacteroides fragilisb | 5 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Bacteroides ureolyticusb | 1 x 106 | TV NOT DETECTED TV DETECTED | ||||||
| Bifidobacterium adolescentisb | Microorganism | 6 x 106 | ConcentrationTesteda | TV NOT DETECTED TV DETECTED | Xpert TV Assay Result | |||
| Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |||||||
| Bifidobacterium brevi (breve)b | Clostridium difficileb | 9 x 106 | 4 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Clostridium perfringensb | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Blastocystis hominisc | Corynebacterium genitalium | 1 x 105 d | 2 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Corynebacterium xerosis | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Branhamella catarrhalis | Cryptococcus neoformanse | 3 x 106 | 5 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Cryptosporidium parvumc | 1 x 105 d | TV NOT DETECTED | TV DETECTED | |||||
| Brevibacterium linens | Cytomegalovirusf | 8 x 106 | 5 x 105 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Deinococcus radiodurans | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Campylobacter jejuni | Derxia gummosa | 2 x 106 | 1 x 106 d | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Eikenella corrodens | 8 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida albicanse | Entamoeba histolyticac | 2 x 106 | 1 x 105 d | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Enterobacter aerogenes | 1 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida glabratae | Enterobacter cloacae | 4 x 106 | 2 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Enterococcus avium | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida parapsilosie | Enterococcus faecalis | 3 x 106 | 7 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Enterococcus faecium | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Candida tropicalise | Erysipelothrix rhusiopathiae | 2 x 106 | 3 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Escherichia coli | 2 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Chlamydia trachomatis | Flavobacterium meningosepticum | 2 x 106 | 5 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Fusobacterium nucleatumb | 4 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Chromobacterium violaceum | Gardnerella vaginalis | 7 x 106 | 2 x 106 | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Gemella haemolysans | 9 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Citrobacter freundii | Giardia intestinalisc | 1 x 106 | 1 x 105 d | TV NOT DETECTED TV DETECTED | TV NOT DETECTED | TV DETECTED | ||
| Haemophilus ducreyi | 1 x 106d | TV NOT DETECTED | TV DETECTED | |||||
| Haemophilus influenzae | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Herpes simplex virus If | 1 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Herpes simplex virus IIf | 1 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| HIV-1f | 2 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Human papilloma virus 16f | 6 x 105 | TV NOT DETECTED | TV DETECTED | |||||
| Kingella dentrificans | 3 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Kingella kingae | 7 x 106 | TV NOT DETECTED | TV DETECTED | |||||
| Klebsiella oxytoca | 1 x 106 | TV NOT DETECTED | TV DETECTED |
Table 5-5. Analytical Specificity/Competitive Interference Determination for
{15}------------------------------------------------
{16}------------------------------------------------
{17}------------------------------------------------
a. Tests run ≥ 10° CFU/mL for bacteria and fungi, ≥10° genomes/mL for yeast, ≥10° U/mL or ≥10°
{18}------------------------------------------------
genomes/mL for viruses and ≥105 cells/mL for protozoans.
- b. Anaerobic organism
- c. Protozoan
- d. Genome equivalents tested (DNA)
- e. Fungal organism
- f. Virus
Table 5-6. Analytical Specificity/Competitive Interference Determination for
{19}------------------------------------------------
{20}------------------------------------------------
| ConcentrationTesteda | Xpert TV Assay Result | ||
|---|---|---|---|
| Microorganism | Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | |
| Klebsiella pneumoniae | 7 x 106 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus acidophilus | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus brevis | 7 x 106 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus crispatus | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus jensonii | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus lactis | 1 x 107 | TV NOT DETECTED | TV DETECTED |
| Lactobacillus vaginalis | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Legionella pneumophila | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Leuconostocparamensenteroides | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Listeria monocytogenes | 8 x 106 | TV NOT DETECTED | TV DETECTED |
| Micrococcus luteus | 3 x 106 | TV NOT DETECTED | TV DETECTED |
| Mobiluncus curtisiib | 3 x 106 | TV NOT DETECTED | TV DETECTED |
| Moraxella lacunata | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Moraxella osloensis | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Morganella morganii | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Mycobacterium smegmatis | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Mycoplasma genitalium | 1 x 106d | TV NOT DETECTED | TV DETECTED |
| Mycoplasma hominis | 1 x 106d | TV NOT DETECTED | TV DETECTED |
| Neisseria cinerea | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria dentrificans | 7 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria elongata | 8 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria flava | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria flavescens | 8 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria gonorrhoeae | 6 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria lactamica | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria mucosa | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria perflava | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria polysaccharea | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria sicca | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Neisseria subflava | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Pantoea agglomerans | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Paracoccus denitrificans | 6 x 106 | TV NOT DETECTED | TV DETECTED |
| Microorganism | ConcentrationTesteda | Xpert TV Assay Result | |
| Cross-Reactivity(- T. vaginalis ) | CompetitiveInterference(+ T. vaginalis ) | ||
| Pentatrichomonis hominisc | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Peptostreptococcus anaerobiusb | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Peptostreptococcus productusb | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Plesiomonas shigelloides | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Prevotella biviab | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Propionibacterium acnesb | 3 x 106 | TV NOT DETECTED | TV DETECTED |
| Proteus mirabilis | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Proteus vulgaris | 7 x 106 | TV NOT DETECTED | TV DETECTED |
| Providencia stuartii | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Pseudomonas aeruginosa | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Pseudomonas fluorescens | 5 x 106 | TV NOT DETECTED | TV DETECTED |
| Pseudomonas putida | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Rahnella aquatilis | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Rhodospirillum rubrum | 1 x 106d | TV NOT DETECTED | TV DETECTED |
| Saccharomyces cerevisiaee | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Salmonella minnesota | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Salmonella typhimurium | 5 x 106 | TV NOT DETECTED | TV DETECTED |
| Serratia marcescens | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Staphylococcus aureus | 9 x 106 | TV NOT DETECTED | TV DETECTED |
| Staphylococcus epidermidis | 5 x 106 | TV NOT DETECTED | TV DETECTED |
| Staphylococcus saprophyticus | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus agalactiae | 6 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus bovis | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus mitis | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus mutans | 5 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus pneumoniae | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus pyogenes | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus salivarius | 3 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptococcus sanguis | 2 x 106 | TV NOT DETECTED | TV DETECTED |
| Streptomyces griseinus | 4 x 106 | TV NOT DETECTED | TV DETECTED |
| Trichomonas tenaxc | 1 x 105 | TV DETECTED | TV DETECTED |
| Trichomonas tenaxc | 1 x 103 | TV DETECTED | TV DETECTED |
| Microorganism | ConcentrationTesteda | Xpert TV Assay Result | |
| Cross-Reactivity(- T. vaginalis) | CompetitiveInterference(+ T. vaginalis) | ||
| Trichomonas tenaxc | 1 x 102 | TV NOT DETECTED | TV DETECTED |
| Ureaplasma parvum | 1 x 106d | TV NOT DETECTED | TV DETECTED |
| Ureaplasma urealyticum | 1 x 106 | TV NOT DETECTED | TV DETECTED |
| Vibrio parahaemolyticus | 3 x 106 | TV NOT DETECTED | TV DETECTED |
| Yersinia enterocolitica | 3 x 106 | TV NOT DETECTED | TV DETECTED |
{21}------------------------------------------------
{22}------------------------------------------------
a. Tests run ≥ 10° CFU/mL for bacteria and fungi, ≥10° genomes/mL for yeast, ≥10° U/mL or ≥10° genomes/mL for viruses and ≥105 cells/mL for protozoans.
b. Anaerobic organism
c. Protozoan
d. Genome equivalents tested (DNA)
e. Fungal organism
f. Virus
Additional three microorganisms, Dientamoeba fragilis, Agrobacterium radiobacter, and Erwinia herbicola, were not available for direct testing. An in silico analysis was conducted using the Basic Local Alignment Search Tool (BLAST) to compare the Xpert TV Assay primer and probe sequences with all available sequences associated with these three microorganisms in the GenBank database. Available sequence data for D. fragilis was examined and showed a maximum of 7% homology to the Xpert TV primer and probe sequences. Available sequence data for A. radiobacter was examined and showed a maximum of 38% homology to the Xpert TV primer and probe sequences. A vailable sequence data for E. herbicola was examined and showed a maximum of 10% homology to the Xpert TV primer and probe sequences. Results are shown in Table 5-7.
Table 5-7. In silico Analytical Specificity Determination for Xpert TV Assay
| Strain | Accession Number | % Homology |
|---|---|---|
| Dientamoeba fragilis | KC967121.1 | 7% |
| Agrobacterium radiobacter | CP000629.1 | 38% |
| Erwinia herbicola | NG_035384.1 | 10% |
Analytical Reactivity (Inclusivity)
The analytical inclusivity of the Xpert TV Assay was evaluated by testing 17 T. vaginalis strains diluted in either negative pooled vaginal swab matrix in Cepheid Xpert Swab Transport Reagent or negative pooled urine in Cepheid Xpert Urine Transport Reagent. All T. vaginalis strains were tested in triplicate at a concentration of 3X the analytical LoD for the respective specimen type (6 cells/mL for vaginal swabs and 7.5 cells/mL for urine). All strains tested were reported as TV DETECTED. Results are shown in Table 5-8. Positive and negative controls were included in the study. The inclusivity for the 17 T. vaginalis strains tested was 100%.
{23}------------------------------------------------
| Isolate ATCC # | Isolation Source | Results VaginalSwab | Results Urine |
|---|---|---|---|
| 30001 | Vaginal exudate | TV DETECTED | TV DETECTED |
| 30184 | Vaginal swab | TV DETECTED | TV DETECTED |
| 30187 | Endocervical swab | TV DETECTED | TV DETECTED |
| 30188 | Vagina | TV DETECTED | TV DETECTED |
| 30236 | Endocervical swab | TV DETECTED | TV DETECTED |
| 30240 | Vaginal pool | TV DETECTED | TV DETECTED |
| 30245 | Vaginal andEndocervical material | TV DETECTED | TV DETECTED |
| 30247 | Vagina | TV DETECTED | TV DETECTED |
| 50138 | human | TV DETECTED | TV DETECTED |
| 50139 | human | TV DETECTED | TV DETECTED |
| 50141 | human | TV DETECTED | TV DETECTED |
| 50143 | human | TV DETECTED | TV DETECTED |
| 50147 | human | TV DETECTED | TV DETECTED |
| 50167 | Vagina | TV DETECTED | TV DETECTED |
| 50183 | Prostatic fluid | TV DETECTED | TV DETECTED |
| PRA-95 | Vaginal exudate | TV DETECTED | TV DETECTED |
| PRA-98 | human | TV DETECTED | TV DETECTED |
Table 5-8: Analytical Reactivity (Inclusivity) of Xpert TV Assay
Interfering Substances Study
The performance of the Xpert TV Assay was evaluated with potentially interfering endogenous and exogenous substances that may be present in the urogenital tract.
All substances were tested in the presence and absence of 3X LoD T. vaginalis (ATCC strain 30001) to determine if there was interference with the Xpert TV Assay. Substances were individually diluted into either pooled Trichomonas vaginalisnegative urine matrix (patient urine added to Cepheid Urine Transport Reagent) or pooled Trichomonas vaginalis-negative vaginal swab matrix (vaginal swabs collected into Cepheid Swab Transport Reagent). Positive and negative controls were included in the study.
For each interfering substance, eight replicates were tested for each set of samples (either T. vaginalis negative or T. vaginalis positive in clinical matrix). Tables 5-9 and 5-10 show the substances that were tested, the test concentrations, and the matrix in which they were diluted. One substance, blood at > 60% v/v demonstrated interference (result of TV NOT DETECTED in the presence of TV) in the vaginal swab matrix samples. Blood was subjected to repeat analysis at various lower concentrations until a result of TV DETECTED was obtained (50% v/v). For the other conditions and substances tested, all TV positive samples remained positive and all TV negative samples remained negative, indicating that there was no interference causing false negative or false positive results with the Xpert TV Assay for these substances.
{24}------------------------------------------------
| Class/Substance | Active Ingredient | Concentration Tested |
|---|---|---|
| Blood | Blood | 0.3% v/v, 1% v/v |
| Mucus | Mucin | 0.8% w/v |
| Analgesics &Antibiotics | Acetylsalicylic Acid 500mg | 40 mg/mL |
| Acetaminophen | 3.2 mg/mL | |
| Azithromycin | 1.8 mg/mL | |
| Doxycycline | 3.6 mg/mL | |
| OTC Deodorant &Powders | PEG-20; PEG-32;PEG-20 Stearate | 0.25% w/v |
| Nanoxynol-9 | 0.25% w/v | |
| Albumin | BSA | 10 mg/ml |
| Glucose | Glucose | 10 mg/ml |
| Bilirubin | Bilirubin | 1 mg/ml |
| Acidic Urine (pH 4.0) | Urine + N-Acetyl-L-Cysteine | pH 4.0 |
| Alkaline Urine (pH 9.0) | Urine + Ammonium Citrate | pH 9.0 |
| Leukocytes | Leukocytes | 105 cells/mL |
| Intravaginal Hormones | Progesterone; Estradiol | 7 mg/mL Progesterone +0.07 mg/mL Beta Estradiol |
Table 5-9: Potentially Interfering Substances in Urine Samples
{25}------------------------------------------------
| Class/Substance | Active Ingredient | Concentration Tested |
|---|---|---|
| Blooda | Blood | 10%, 50%, 60% v/v |
| Seminal Fluid | Seminal Fluid | 5.0% v/v |
| Mucus | Mucin | 0.8% w/v |
| Over the counter (OTC) Vaginal Products;Contraceptives; Vaginaltreatments | Benzocaine 5%;Resorcinol 2% | 0.25% w/v |
| Clotrimazole 2% | 0.25% w/v | |
| Miconazole Nitrate 2% | 0.25% w/v | |
| Tioconazole | 0.25% w/v | |
| 5% w/w Aciclovir | 0.25% w/v | |
| Glycerin, Propylene glycol | 0.25% w/v | |
| Glycerin; Carbomer | 0.12% w/v | |
| Glycerin, Hydroxyethyl cellulose | 0.25% w/v | |
| Goldenseal 3X HPUS;Kreosotum 12X HPUS | 0.25% w/v | |
| Povidone-iodine 10% | 0.25% v/v | |
| Nonoxynol-9 12.5% | 0.25% w/v | |
| Hemorrhoidal Cream | Glycerin 14%;Pramoxine HCl 1% | 0.25% w/v |
| Leukocytes | Leukocytes | 105 cells/mL |
| Intravaginal Hormones | Progesterone; Estradiol | 7 mg/mL Progesterone +0.07 mg/mL Beta Estradiol |
Table 5-10: Potentially Interfering Substances in Swab Samples
a. In tests with substances diluted into pooled T. vaginalis-positive swab matrix, assay interference was observed in tests with blood at 60% v/v. No assay interference was observed in tests with blood at 50% v/v. This is addressed in Limitations in the package insert.
Carry-Over Contamination
This study was conducted to demonstrate that single-use, self-contained GeneXpert cartridges prevent carry-over contamination in negative samples run after very high positive samples in the same GeneXpert module. A negative sample (T. vaginalis negative vaginal swabs in Cepheid Xpert Swab Transport Reagent) was run followed by 20 rounds of high positive sample (T. vaginalis ATCC 30001 at 106 cells/mL diluted in vaginal swab matrix) alternated with negative sample in two separate GeneXpert modules for a total of 40 high positive and 42 negative samples for each module. This testing scheme resulted in a total of 82 runs (40 positive + 42 negative single-use samples). There was no evidence of carry-over contamination as all 40 positive samples were correctly reported as TV DETECTED and all 42 negative samples were correctly reported as TV NOT DETECTED.
Linearity
Not applicable, the Xpert TV Assay is a qualitative assay.
{26}------------------------------------------------
Clinical Studies
Clinical Performance
Performance characteristics of the Xpert TV Assay were determined in a multi-site prospective investigational study by comparing the results from the Xpert TV Assay to a patient infected status (PIS) algorithm comprised of an FDA cleared NAAT test and culture.
Study participants included consenting asymptomatic and symptomatic, sexually active females seen at locations including, but not limited to: OB/GYN, sexually transmitted disease (STD), and family planning clinics. The average age among eligible study participants was 33.5 years (range = 18 to 78 years).
The study specimens consisted of prospectively collected urine, endocervical swabs and patient-collected vaginal swabs (collected in a clinical setting). Clinician-collected vaginal swabs were collected for testing by the reference NAAT test and culture. Samples were collected from 17 clinical sites and tested at 11 sites. Reference testing was performed at 3 central laboratories.
A study participant was considered to be infected by PIS if either of the reference test (NAAT and culture) results were positive. The subject was considered to be not infected by PIS when both reference test results were negative.
Performance of the Xpert TV Assay was calculated relative to the PIS for each of the three specimen types (endocervical swabs, patient-collected vaginal swabs and urine).
Specimens with discrepant results between the Xpert TV Assay and the PIS were analyzed by validated bi-directional Sanger sequencing and results are footnoted in Table 5-11 for informational purposes only.
Among the 5391 tests performed, 85 had initial ERROR, INVALID or NO RESULT outcomes (1.58%, 95% CI 1.26-1.95). Of those, 77 specimens yielded valid results upon repeat assay (2 specimens were not retested). The overall valid reporting rate of the assay was 99.9% (5383/5391).
Results of the Xpert TV Assay were compared to the PIS algorithm for determination of sensitivity, specificity, and predictive values. Sensitivity and specificity for TV by specimen type and symptom status are presented in Table 5-11.
{27}------------------------------------------------
| Sample Type | Status | Total (n) | Sens | 95% CI | Spec | 95% CI | Prev (%) | PPV (%) | NPV (%) |
|---|---|---|---|---|---|---|---|---|---|
| ES | Symp | 685 | 100%(71/71) | 94.9%-100% | 98.5%(605/614) | 97.2%-99.3% | 10.4% | 88.8% | 100% |
| Asymp | 1114 | 98.1%(104/106) | 93.4%-99.8% | 99.1%(999/1008) | 98.3%-99.6% | 9.5% | 92.0% | 99.8% | |
| Overall | 1799 | 98.9%(175/177)a | 96.0%-99.9% | 98.9%(1604/1622)b | 98.3%-99.3% | 9.8% | 90.7% | 99.9% | |
| Difference | P-Value | P=0.517 | -0.70%, 4.48% | P=0.331 | -1.69%, 0.54% | ||||
| PC-VS | Symp | 682 | 98.6%(73/74) | 92.7%-100% | 99.5%(605/608) | 98.6%-99.9% | 10.9% | 96.1% | 99.8% |
| Asymp | 1109 | 95.0%(113/119) | 89.3%-98.1% | 99.6%(986/990) | 99.0%-99.9% | 10.7% | 96.6% | 99.4% | |
| Overall | 1791 | 96.4%(186/193)c | 92.7%-98.5% | 99.6%(1591/1598)d | 99.1%-99.8% | 10.8% | 96.4% | 99.6% | |
| Difference | P-Value | P=0.254 | -1.04%, 8.42% | P=1.000 | -0.77%, 0.59% | ||||
| UR | Symp | 688 | 98.6%(71/72) | 92.5%-100% | 99.8%(615/616) | 99.1%-100% | 10.5% | 98.6% | 99.8% |
| Asymp | 1105 | 98.2%(109/111) | 93.6%-99.8% | 99.6%(990/994) | 99.0%-99.9% | 10.0% | 96.5% | 99.8% | |
| Overall | 1793 | 98.4%(180/183)e | 95.3%-99.7% | 99.7%(1605/1610)f | 99.3%-99.9% | 10.2% | 97.3% | 99.8% | |
| Difference | P-Value | P=1.000 | -3.25%, 4.08% | P=0.655 | -0.27%, 0.75% |
Table 5-11: Xpert TV vs. PIS by Symptomatic Status
TP=true positive, FP=false positive, TN=true negative, ES=endocervical swab, PC VS=patient-collected vaginal swab, UR=urine a. Testing results by sequencing: 1 of 2 FN was TV positive; 1 of 2 was TV negative.
b. Testing results by sequencing: 8 of 18 FP were TV positive; 10 of 18 were TV negative.
c. Testing results by sequencing: 3 of 7 FN were TV positive; 4 of 7 were TV negative.
d. Testing results by sequencing: 5 of 7 FP were TV positive; 2 of 7 were TV negative.
e. Testing results by sequencing: 3 of 3 FN were TV negative.
f. Testing results by sequencing: 5 of 5 FP were TV negative.
{28}------------------------------------------------
Cycle Threshold (Ct) Frequency Distribution
Patient-collected vaginal swabs, endocervical swabs and urine specimens were collected from 1867 females at 17 collection sites in the US. The frequency distribution of Xpert TV Assay positive results for the 197 Trichomonas vaginalis infected study subjects are shown in Figure 5-1.
Image /page/28/Figure/2 description: This image is a histogram displaying the distribution of Ct values for specimens. The x-axis represents Ct values, ranging from 10 to 40, while the y-axis represents the number of specimens, ranging from 0 to 50. The histogram shows a distribution that peaks between Ct values of 25 and 30, indicating that most specimens have Ct values in this range. The number of specimens decreases as Ct values move away from this peak.
Figure 5-1. Ct Distribution of Patients Designated as Positive for TV Based on PIS Algorithm
Reproducibility Study
Intra-site reproducibility of the Xpert TV Assay was evaluated at three sites (two external, one in-house). Site 1 used an Infinity-80 instrument. Sites 2 and 3 used GeneXpert Dx instruments. Specimens were created by spiking Trichomonas vaginalis (ATCC® 30001™) into pooled, Trichomonas vaginalis negative urine (patient urine added to Cepheid Urine Transport Reagent) or vaginal swab matrix (vaginal swabs collected into Cepheid Swab Transport Reagent). The specimens were prepared at concentration levels representing high negative (below LoD), LoD (~1X LoD, moderate positive (~3X LoD), and negative (Trichomonas vaginalis negative clinical matrix). A panel of 8 specimens (4 in urine and 4 in vaginal swab matrix) was tested twice per day, on 12 different days, by two different operators, at each of three sites (8 specimens x 2 replicates x 12 days x 2 operators x 3 sites = 1,152 observations total). Three lots of Xpert TV Assay cartridges were used at each of the 3 testing sites, with each lot used for 4 days of testing. Positive and negative controls were included in the study. The Xpert TV Assay was performed according to the Xpert TV Assay procedure. The rate of agreement with expected results is shown by site in Table 5-12.
{29}------------------------------------------------
| Samplea | Site 1(Infinity-80) | Site 2(GeneXpert Dx) | Site 3(GeneXpert Dx) | TotalAgreementby Sample | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Op 1 | Op 2 | Site | Op 1 | Op 2 | Site | Op 1 | Op 2 | Site | ||
| FS-Neg | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(144/144) |
| FS-Mod Pos(~3X LoD;~6 cells/mL) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(144/144) |
| FS-LoD(~1X LoD;~2 cells/mL) | 95.8%(23/24) | 100%(24/24) | 97.9%(47/48) | 87.5%(21/24) | 95.8%(23/24) | 91.7%(44/48) | 100%(24/24) | 95.8%(23/24) | 97.9%(47/48) | 95.8%(138/144) |
| FS-High Neg(below LoD;< 2 cells/mL) | 87.5%(21/24) | 75.0%(18/24) | 81.3%(39/48) | 66.7%(16/24) | 79.2%(19/24) | 72.9%(35/48) | 79.2%(19/24) | 70.8%(17/24) | 75.0%(36/48) | 76.4%(110/144) |
| UR-Neg | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(144/144) |
| UR-Mod Pos(~3X LoD;~9 cells/mL) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(24/24) | 100%(24/24) | 100%(48/48) | 100%(144/144) |
| UR-LoD(~1X LoD;~3 cells/mL) | 75.0%(18/24) | 91.7%(22/24) | 83.3%(40/48) | 83.3%(20/24) | 91.3%(21/23)b | 87.2%(41/47) | 91.7%(22/24) | 100%(24/24) | 95.8%(46/48) | 88.8%(127/143) |
| UR-High Neg(below LoD;< 3 cells/mL) | 75.0%(18/24) | 75.0%(18/24) | 75.0%(36/48) | 70.8%(17/24) | 54.2%(13/24) | 62.5%(30/48) | 75.0%(18/24) | 75.0%(18/24) | 75.0%(36/48) | 70.8%(102/144) |
Table 5-12: Summary of Reproducibility Results
a. FS=female swab matrix; UR= urine matrix.
b. One sample indeterminate on initial and retest.
The reproducibility of the Xpert TV Assay was also evaluated in terms of the fluorescence signal expressed in Ct values for each target detected. The mean, standard deviation (SD), and coefficient of variation (CV) between-sites, between-lots, betweendays, between-operators, and residual variability for each panel member are presented in Table 5-13.
{30}------------------------------------------------
| Samplea | AssayChannel(Analyte) | Nb | MeanCt | Between-Site | Between-Lot | Between-Day | Between-Operator | Residual | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SD | CV(%)c | SD | CV(%)c | SD | CV(%)c | SD | CV(%)c | SD | CV(%)c | SD | CV(%)c | ||||
| FS-Neg | SPC | 144 | 33.7 | 0.0 | 0.0 | 0.1 | 23.2 | 0.1 | 8.9 | 0.0 | 0.0 | 0.4 | 67.9 | 0.4 | 1.2 |
| FS-Mod Pos(~3X LoD;~6 cells/mL) | TV | 144 | 35.4 | 0.1 | 7.9 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 12.5 | 0.8 | 79.7 | 0.8 | 2.3 |
| FS-LoD( | TV | 138 | 38.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.5 | 28.0 | 0.0 | 0.0 | 1.2 | 72.0 | 1.3 | 3.5 |
| FS-High Neg(below LoD;< 2 cells/mL) | TV | 110 | 39.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 17.6 | 0.0 | 0.0 | 1.7 | 82.4 | 1.8 | 4.5 |
| UR-Neg | SPC | 144 | 33.9 | 0.1 | 8.6 | 0.0 | 0.0 | 0.1 | 9.0 | 0.1 | 18.5 | 0.4 | 63.9 | 0.4 | 1.2 |
| UR-Mod Pos(~3X LoD;~9 cells/mL) | TV | 144 | 35.5 | 0.2 | 22.3 | 0.1 | 9.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.6 | 67.9 | 0.7 | 1.9 |
| UR-LoD(~1X LoD;~3 cells/mL) | TV | 127 | 39.3 | 0.0 | 0.0 | 0.4 | 24.4 | 0.0 | 0.0 | 0.0 | 0.0 | 1.2 | 75.6 | 1.3 | 3.4 |
| UR-High Neg(below LoD;< 3 cells/mL) | TV | 102 | 39.0 | 0.0 | 0.0 | 0.3 | 14.4 | 0.7 | 29.5 | 0.3 | 11.6 | 1.0 | 44.6 | 1.3 | 3.3 |
Table 5-13: Summary of Reproducibility Data
a. FS=female swab matrix; UR= urine matrix.
b. Results with non-zero Ct values out of 144.
c. (%) is contribution of variance component to overall CV.
Instrument System Precision
An in-house precision study was conducted to compare the performance of the GeneXpert Dx and the GeneXpert Infinity Instrument Systems using specimens comprised of Trichominas vaginalis (ATCC® 30001™) spiked into negative urine (patient urine added to Cepheid Urine Transport Reagent) or vaginal swab matrix (vaginal swabs collected into Cepheid Swab Transport Reagent). The specimens were prepared at concentration levels representing low positive (below LoD), LoD (~1X LoD), moderate positive (~3X LoD), and negative (Trichomonas vaginalis negative clinical matrix). A panel of 8 specimens (4 in urine matrix and 4 in vaginal swab matrix) was tested on 12 different days by two operators. Each operator conducted four runs of each panel specimen per day on each of the three instrument systems (8 specimens x 4 times/day x 12 days x 2 operators x 3 instrument systems = 2,304 observations total). Three lots of Xpert TV Assay cartridges were used for the study, with each lot used for 4 days of testing. Positive and negative controls were included in the study. The Xpert TV
{31}------------------------------------------------
Assay was performed according to the Xpert TV Assay procedure. The rate of agreement with expected results is shown by instrument in Table 5-14.
| Samplea | GeneXpert Dx | Infinity-48 | Infinity-80 | % TotalAgreementby Sample | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Op 1 | Op 2 | Inst | Op 1 | Op 2 | Inst | Op 1 | Op 2 | Inst | ||
| FS-Neg | 100%(48/48) | 100%(48/48) | 100%(96/96) | 97.9%(47/48) | 100%(48/48) | 99.0%(95/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 99.7%(287/288) |
| FS-Mod Pos(~3X LoD;~6 cells/mL) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(288/288) |
| FS-LoD( | 93.8%(45/48) | 87.5%(42/48) | 90.6%(87/96) | 93.8%(45/48) | 89.6%(43/48) | 91.7%(88/96) | 95.8%(46/48) | 89.6%(43/48) | 92.7%(89/96) | 91.7%(264/288) |
| FS-High Neg(below LoD;< 2 cells/mL) | 74.5%(35/47) | 75.0%(36/48) | 74.7%(71/95) | 77.1%(37/48) | 75.0%(36/48) | 76.0%(73/96) | 83.3%(40/48) | 68.8%(33/48) | 76.0%(73/96) | 75.6%(217/287)b |
| UR-Neg | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(47/47) | 100%(95/95) | 100%(287/287)b |
| UR-Mod Pos(~3X LoD;~9 cells/mL) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(48/48) | 100%(48/48) | 100%(96/96) | 100%(288/288) |
| UR-LoD(~1X LoD;~3 cells/mL) | 93.8%(45/48) | 93.8%(45/48) | 93.8%(90/96) | 95.8%(46/48) | 89.6%(43/48) | 92.7%(89/96) | 95.8%(46/48) | 95.8%(46/48) | 95.8%(92/96) | 94.1%(271/288) |
| UR-High Neg(below LoD;< 3 cells/mL) | 72.9%(35/48) | 77.1%(37/48) | 75.0%(72/96) | 70.8%(34/48) | 79.2%(38/48) | 75.0%(72/96) | 81.3%(39/48) | 85.4%(41/48) | 83.3%(80/96) | 77.8%(224/288) |
Table 5-14: Summary of Precision Results
a. FS=female swab matrix; UR= urine matrix.
b. One FS-Low Pos and one UR-Neg sample indeterminate and not retested.
The precision of the Xpert TV Assay was also evaluated in terms of the fluorescence signal expressed in Ct values for each target detected. The mean, standard deviation (SD), and coefficient of variation (CV) between-instruments, between-lots, between-days, between-operators, and residual variability for each panel member are presented in Table 5-15.
{32}------------------------------------------------
| Sampleª | AssayChannel(Analyte) | Nᵇ | MeanCt | Between-Instrument | Between-Lot | Between-Day | Between-Operator | Residual | Total | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SD | CV(%)ᶜ | SD | CV(%)ᶜ | SD | CV(%)ᶜ | SD | CV(%)ᶜ | SD | CV(%)ᶜ | SD | CV(%)ᶜ | ||||
| FS-Neg | SPC | 288 | 31.9 | 0.0 | 0.0 | 0.3 | 53.5 | 0.0 | 0.0 | 0.1 | 1.9 | 0.2 | 44.6 | 0.4 | 1.1 |
| FS-Mod Pos(~3X LoD;~6 cells/mL) | TV | 288 | 35.2 | 0.0 | 0.0 | 0.3 | 22.4 | 0.0 | 0.0 | 0.1 | 4.5 | 0.4 | 73.1 | 0.5 | 1.5 |
| FS-LoD( | TV | 264 | 39.0 | 0.2 | 3.3 | 0.1 | 0.4 | 0.2 | 1.3 | 0.0 | 0.0 | 1.3 | 95.0 | 1.3 | 3.4 |
| FS-High Neg(below LoD;< 2 cells/mL) | TV | 217 | 39.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.2 | 1.6 | 1.3 | 98.4 | 1.3 | 3.2 |
| UR-Neg | SPC | 287 | 32.4 | 0.0 | 0.0 | 0.3 | 47.2 | 0.1 | 2.9 | 0.0 | 0.0 | 0.3 | 49.9 | 0.4 | 1.2 |
| UR-Mod Pos(~3X LoD;~9 cells/mL) | TV | 288 | 35.4 | 0.0 | 0.0 | 0.4 | 30.4 | 0.0 | 0.0 | 0.2 | 11.3 | 0.5 | 58.3 | 0.6 | 1.8 |
| UR-LoD(~1X LoD;~3 cells/mL) | TV | 271 | 38.2 | 0.0 | 0.0 | 0.5 | 13.6 | 0.6 | 16.2 | 0.3 | 3.6 | 1.2 | 66.5 | 1.4 | 3.7 |
| UR-High Neg(below LoD;< 3 cells/mL) | TV | 224 | 38.9 | 0.0 | 0.0 | 0.3 | 5.4 | 0.0 | 0.0 | 0.3 | 4.2 | 1.2 | 90.3 | 1.3 | 3.3 |
Table 5-15: Summary of Precision Data
a. FS=female swab matrix; UR=urine matrix.
b. Results with non-zero Ct values out of 288.
c. (%) is contribution of variance component to overall CV.
Conclusions
The results of the nonclinical analytical and clinical performance studies summarized above demonstrate that the Xpert TV Assay is substantially equivalent to the predicate device.
§ 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.