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The Genetic Signatures EasyScreen™ Gastrointestinal Parasite Detection Kit is a rapid in vitro nucleic acid amplification assay for the qualitative detection of pathogenic gastrointestinal parasite nucleic acid from the stool of patients with signs and/or symptoms of gastroenteritis. The test, based on real-time PCR, detects the nucleic acid of the following organisms:

• · Cryptosporidium spp.
• · Giardia intestinalis
• Dientamoeba fragilis
• · Entamoeba histolytica
• Blastocystis hominis
• · Enterocytozoon bieneusi
• · Encephalitozoon intestinalis
• · Cyclospora cayetanensis

The kit is compatible with stool specimens that are unpreserved or frozen or in transport media including Cary Blair or C&S media from symptomatic patients with suspected gastroenteritis. It is required that the stool is first processed using the EasyScreen™ Sample Processing Kit. Nucleic acid extraction and real-time PCR set up are performed on the automated Genetic Signatures GS1 platform.

This device is an in vitro diagnostic (IVD) intended to be used by trained personnel in clinical, pathology or hospital laboratories as an aid in the diagnosis of gastrointestinal illness. This test is intended for use, in conjunction with clinical presentation, laboratory findings, and epidemiological information, as an aid in the differential diagnosis of infections by Dientamoeba fragilis, Blastocystis hominis, Enterocytozoon bieneusis, Entamoeba histolytica, Encephalitozoon intestinalis, Cryptosporidium spp. (including C. parvum), and Giardia intestinalis. Results of this test should not be used as the sole basis for diagnosis, treatment, or other patient management decision. Positive results do not rule out co-infection with other organisms that are not detected by this test, and may not indicate the sole or definitive cause of patient illness. Negative results in the setting of clinical illness compatible with gastroenteritis and/or colitis may be due to infection by pathogens that are not detected by this test or non-infectious causes such as ulcerative colitis, irritable bowel syndrome, or Crohn's disease.

The EasyScreen™ Gastrointestinal Parasite Detection Kit (EP005) is designed to simultaneously identify 8 potential pathogens of the gastrointestinal tract, from human stool samples. The device is only compatible with nucleic acids prepared using an EasyScreen™ Sample Processing Kit (SP008B).

A stool sample from a patient suspected of having gastroenteritis (usually liquid or soft stool) is collected and transported to the testing laboratory. A portion of the stool material is taken using a swab or pipette and processed with the EasyScreen™ Sample Processing Kit (SP008B), which lyses cells and converts the nucleic acid to a 3base™ form.

An aliquot of purified eluate is then added to the PCR reagents supplied in the EP005 kit, which selectively amplify the genetic targets of Cryptosporidium spp., Giardia intestinalis, Entamoeba Dientamoeba fragilis, Blastocystis hominis, Enterocytozoon histolytica. bieneusi. Encephalitozoon intestinalis and Cyclospora cayetanensis. The reaction mix is manufactured to detect an Extraction Control (EC) and features an incorporated Internal Positive Control (IPC) to determine the reliability of the extracted nucleic acid and to detect the presence of any inhibitors after extraction from the primary sample.

Amplified targets are detected with probes labeled with fluorophores as detected by the real-time PCR platform. The PCR amplification takes approximately 150 minutes, depending on the PCR platform used. A positive control is included to ascertain that the detection reagents and analyzer are functioning correctly.

The amplified nucleic acid targets are detected by probes labeled with fluorophores, as detected by the real-time PCR platform. If no amplification occurs for a given target, then there will not be any significant increase in fluorescence. Each probe fluoresces at a given wavelength and the signals are measured and distinguished from each other by the real-time PCR platform. The realtime PCR software interprets all data collection and provides the information for automated or manual result analysis. The assay is semi-automated.

The provided text describes the performance of the Genetic Signatures EasyScreen™ Gastrointestinal Parasite Detection Kit. This device is a rapid in vitro nucleic acid amplification assay for the qualitative detection of pathogenic gastrointestinal parasite nucleic acid from human stool samples.

Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided document:

1. Table of Acceptance Criteria and Reported Device Performance

The document does not explicitly present a consolidated table of acceptance criteria for all aspects of the study alongside the reported performance in a single, clear format. However, acceptance criteria are stated within each section of the performance studies, and the results are then presented against those criteria. Below is a reconstructed table based on the explicit statements regarding acceptance and observed performance.

Acceptance Criteria and Reported Device Performance

2. Sample size used for the test set and the data provenance

• Clinical Study Test Set (Analyzable Samples): A total of 1,926 analyzable specimens (out of 2,806 collected).
  • Prospective Samples (Category I & II): 1,461 samples.
  • Retrospective Clinical Samples (Category III): 265 samples.
  • Contrived Samples (Category IV): 165 samples (for E. bieneusi and E. intestinalis, which had low prevalence or availability).
• Data Provenance:
  • Clinical Samples: Collected from four geographically diverse US clinical sites (US1, US2, US3, US4). Some retrospective procurement was also done at one US site (US4).
  • Contrived Samples: Prepared/enrolled at an Outside the US (OUS) internal site for testing at the US sites.
  • Retrospective or Prospective: Both retrospective and prospective samples were used. Prospective samples (Category I: fresh, and Category II: frozen) were collected in an "All-Comers" mode. Retrospective, positive-identified (Category III) samples were also included, along with randomly distributed negative samples, tested in a masked/blinded manner.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts

The document does not specify the number or qualifications of experts used to establish the ground truth for the test set. It mentions that the reference method for the clinical studies was "two (2) well-characterized and validated Nucleic Acid Amplification Tests (NAAT) followed by bi-directional sequencing (referred to as "alternative NAAT")." The alternative NAATs were performed at an OUS internal site. The results from the alternative NAAT were compared against sequence data that met "acceptability criteria listed in Section VII(D)(1) of the Class II Special Controls guidelines," but it does not detail human expert adjudication for ground truth. The adjudication of sequence data to determine ground truth status appears to be based on pre-defined criteria rather than a panel of human experts.

4. Adjudication method (e.g., 2+1, 3+1, none) for the test set

The document states that the true analyte status ("positive" or "negative") of each clinical sample was established for each target parasite by comparison with the reference method of alternative NAATs. These NAATs consisted of "two separate single-plex, PCR amplification tests." Amplicons from PCR-positive reactions were then subjected to "bi-directional Sanger sequencing." Samples producing sequence data that met "acceptability criteria" were reported as positive by alternative NAAT.

There is no mention of a human expert adjudication method (like 2+1 or 3+1 consensus) for the resolution of discrepancies between multiple readers or ground truth methods. The ground truth appears to be established algorithmically or through a predefined analytical process based on the output of the reference NAATs and sequencing results.

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 is not an AI/human-in-the-loop study. The device described is an in vitro diagnostic (IVD) molecular test (real-time PCR kit) for detecting pathogenic gastrointestinal parasite nucleic acid. Therefore, an MRMC comparative effectiveness study involving human readers assisted by AI is not applicable here. The device output is qualitative (detection or non-detection of specific nucleic acids), interpreted directly by the instrument software or through a validated macro-enabled Excel sheet, not by human image readers.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Yes, the primary performance evaluation of the EasyScreen™ Gastrointestinal Parasite Detection Kit is a standalone (algorithm only) performance assessment. The device is a diagnostic kit that performs nucleic acid amplification and detection. The interpretation of results is automated, with the real-time PCR software interpreting data and providing information for automated or manual result analysis. The device itself (the kit and associated platform) is the "algorithm" in this context, directly generating a result based on the processed sample without human interpretation of raw signals like an image.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The ground truth for the clinical study was established using a molecular reference method: "two (2) well-characterized and validated Nucleic Acid Amplification Tests (NAAT) followed by bi-directional sequencing (referred to as "alternative NAAT")". Sequence data meeting predefined acceptability criteria were considered positive. This is a form of molecular ground truth, not expert consensus, pathology, or outcomes data.

8. The sample size for the training set

The document does not specify a separate training set size or mention a training phase for the device described. As an in vitro diagnostic (IVD) PCR kit, its "training" or "development" would involve optimizing primers, probes, and reaction conditions rather than machine learning algorithm training on a dataset in the typical sense. The studies described are validation studies (analytical and clinical performance) on test sets.

9. How the ground truth for the training set was established

Since a specific training set or "training phase" in the context of machine learning is not described for this IVD device, the method for establishing ground truth for a training set is not applicable or described in the provided document. The document focuses on the validation of the finalized device.

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