(23 days)
The QIAstat-Dx GI Panel 2 Mini B is a multiplexed nucleic acid test intended for use with the OIAstat-Dx Analyzer 1.0 for the simultaneous in vitro qualitative detection of nucleic acids from multiple bacteria directly from preserved stool samples (Para-Pak C&S or FecalSwab) obtained from individuals with signs and/or symptoms of gastrointestinal infection. The following bacteria (including several diarrheagenic E. coli/Shigella pathotypes) are identified with the QIAstat-Dx GI Panel 2 Mini B:
- Campylobacter
- Shigella
- Shiga-like toxin Escherichia coli (STEC)*
- Salmonella
- Yersinia enterocolitica
*Only with Para-Pak C&S, not reported for FecalSwab
Concomitant culture is necessary for organism recovery and further typing of bacterial agents. The QlAstat-Dx GI Panel 2 Mini B is indicated as an aid in the diagnosis of specific agents of gastrointestinal illness, in conjunction with other clinical, laboratory, and epidemiological data. Postive results do not rule out co-infection with organisms not detected by the QIAstat-Dx GI Panel 2 Mini B. The organisms detected may not be the sole or definitive cause of the disease.
Negative QIAstat-Dx GI Panel 2 Mini B results in the setting of clinical illness compatible with gastroenteritis may be due to infection by pathogens that are not detected by this assay test or non-infectious causes such as ulcerative colitis, irritable bowel syndrome, or Crohn's disease.
The QIAstat-Dx® GI Panel 2 Mini B (Cat. no. 691423) assay is a modified device (reduced version) of the OIAstat-Dx Gastrointestinal Panel 2 (Cat. no. 691421). The OIAstat-Dx GI Panel 2 Mini B is identical to the QIAstat-Dx Gastrointestinal Panel 2 (K220062) but uses an Assay Definition File (ADF) which masks all but five pathogens (targets) from the OIAstat-Dx Gastrointestinal Panel 2. The following bacteria (including several diarrheagenic E. coli/Shigella pathotypes) are identified with the OIAstat-Dx GI Panel 2 Mini B: Campvlobacter. Shigella, Shiga-like toxin E. coli (STEC), Salmonella and Yersinia enterocolitica. The QIAstat-Dx GI Panel 2 Mini B is part of the QIAstat-Dx system and works with the OIAstat-Dx Analyzer 1.0. It will be available in a separately labeled kit.
The QIAstat-Dx GI Panel 2 Mini B is intended to be used with stool samples in Para-Pak C&S or FecalSwab transport media.
QIAstat-Dx is based on single-test cartridges with pre-packaged reagents including both wet and dry chemistry to handle the sample preparation and detection steps for the presence of a range of selected analytes by PCR technology. After insertion of the sample, the QIAstat-Dx assay cartridge is processed by the QIAstat-Dx Analyzer 1.0.
Once the cartridge is inserted into the instrument, the test starts automatically and runs for about 78 minutes. When the test is finished, the cartridge is removed by the user and discarded. The QIAstat-Dx Analyzer 1.0 automatically interprets test results and displays a summary on the analyzer display screen. The results can be printed using a connected printer if needed. The detected analytes are displayed in red. For other analytes tested, they are displayed in green if not detected or in grav if not applicable or invalid. The analyzer will report if an error occurs during processing, in which case the test will fail and no results will be provided (screen will show "FAIL").
All the reagents required for the complete execution of the test are pre-loaded and selfcontained in the QIAstat-Dx GI Panel 2 Mini B cartridge. The user does not need to manipulate any reagents. During the test, reagents are handled by pneumatically operated microfluidics without any direct contact with the user or the analyzer actuators.
Within the cartridge, multiple steps are automatically performed in sequence by using pneumatic pressure and a multiport valve to transfer sample and fluids via the Transfer Chamber (TC) to their intended destinations. Following the introduction of the sample from a disposable transfer pipette, the following assay steps occur automatically and sequentially:
- Sample Pre-treatment for PCR Inhibitors removal
- Resuspension of Internal Control and Proteinase K
- Cell lysis using mechanical and/or chemical means
- Membrane-based nucleic acid purification
- Rehydration of Master Mix
- Transfer of defined aliquots of eluate/master mix to different reaction chambers
- Performance of multiplex real-time RT-PCR testing within each reaction chamber.
The provided text does not contain detailed acceptance criteria or a study that explicitly proves the device meets those criteria in a format with numerical results and statistical analyses typical for such studies. It states that the performance data for the QIAstat-Dx GI Panel 2 Mini B is equivalent to the predicate device (QIAstat-Dx Gastrointestinal Panel 2, K220062) for the five specific analytes it detects. It also mentions that the "QIAGEN QIAstat-Dx GI Panel 2 Mini B Instructions for Use" should be consulted for performance tables, which are not included in this document.
However, based on the information provided, I can infer the general nature of the acceptance criteria (qualitative detection of specific pathogens) and describe the comparative nature of the "study" (equivalence to a predicate device).
Here's an attempt to structure the information based on your request, with significant caveats that detailed numerical results, sample sizes, expert qualifications, and study methodologies for the actual performance are not present in the provided text.
Acceptance Criteria and Device Performance for QIAstat-Dx GI Panel 2 Mini B
The QIAstat-Dx GI Panel 2 Mini B is a modified version of the predicate device, QIAstat-Dx Gastrointestinal Panel 2 (K220062). The device performance for the QIAstat-Dx GI Panel 2 Mini B is presented as being equivalent to the predicate device for the five target analytes it identifies.
1. Table of Acceptance Criteria and Reported Device Performance
Since specific numerical acceptance criteria and performance metrics (e.g., sensitivity, specificity, PPV, NPV) are not provided in this document, the table below reflects the qualitative nature of the information given. The "acceptance criteria" are inferred from the demonstrated performance equivalence to the predicate device for the detected analytes.
| Analyte (Bacteria) | Acceptance Criteria (Inferred) | Reported Device Performance (Summary) |
|---|---|---|
| Campylobacter | Qualitative detection equivalent to predicate device (K220062) | Performance equivalent to QIAstat-Dx Gastrointestinal Panel 2 (K220062) for Campylobacter |
| Shigella | Qualitative detection equivalent to predicate device (K220062) | Performance equivalent to QIAstat-Dx Gastrointestinal Panel 2 (K220062) for Shigella |
| Shiga-like toxin Escherichia coli (STEC) | Qualitative detection equivalent to predicate device (K220062) | Performance equivalent to QIAstat-Dx Gastrointestinal Panel 2 (K220062) for STEC |
| Salmonella | Qualitative detection equivalent to predicate device (K220062) | Performance equivalent to QIAstat-Dx Gastrointestinal Panel 2 (K220062) for Salmonella |
| Yersinia enterocolitica | Qualitative detection equivalent to predicate device (K220062) | Performance equivalent to QIAstat-Dx Gastrointestinal Panel 2 (K220062) for Yersinia enterocolitica |
2. Sample Size Used for the Test Set and Data Provenance
The provided document does not specify the sample size used for the test set or the data provenance (e.g., country of origin, retrospective/prospective nature). It simply states that the performance data for the modified device is "equivalent" to the predicate device. To find this information, one would need to refer to the 510(k) submission K220062 for the predicate device and/or the "QIAGEN QIAstat-Dx GI Panel 2 Mini B Instructions for Use."
3. Number of Experts and Qualifications
The document does not mention the number of experts used to establish ground truth or their qualifications. This information would typically be found in the detailed performance study report of the predicate device, or IFU for the current device. Given that the device detects nucleic acids for specific bacteria, ground truth is likely established through culture or other confirmed molecular methods, rather than expert consensus on images.
4. Adjudication Method
The document does not specify any adjudication method (e.g., 2+1, 3+1, none) for the test set. This type of method is more common in image-based AI studies where human interpretation can vary; for a nucleic acid test, ground truth is typically established by definitive laboratory methods.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
An MRMC comparative effectiveness study was not applicable or performed for this device as it is a standalone in vitro diagnostic (IVD) device for nucleic acid detection, not an AI-assisted diagnostic tool for human readers. Therefore, there is no effect size related to human reader improvement with AI assistance.
6. Standalone Performance
Yes, a standalone performance assessment was conducted. The QIAstat-Dx GI Panel 2 Mini B is an in vitro diagnostic device, meaning its performance (analytical and clinical performance) is evaluated independently without human interpretation as part of a human-in-the-loop system. The document states its performance is "equivalent" to the predecessor device, which would have undergone rigorous standalone performance testing.
7. Type of Ground Truth Used
While not explicitly stated for this specific submission, for a nucleic acid-based assay like the QIAstat-Dx GI Panel 2 Mini B, the ground truth would typically be established by:
- Culture: Bacterial culture for viability and identification of the target organisms.
- Reference Molecular Methods: e.g., validated PCR assays or sequencing for definitive detection and identification of microbial nucleic acids.
- Composite Reference Method (CRM): A combination of multiple methods, often including culture, microscopy, and/or multiple molecular methods, to establish the presence or absence of the target pathogen.
8. Sample Size for the Training Set
The document does not provide the sample size for the training set. For an IVD like this, "training set" might refer to the data used for initial assay development and optimization rather than a machine learning context. This information would be in the detailed development reports.
9. How the Ground Truth for the Training Set Was Established
The document does not describe how the ground truth for the training set was established. Similar to the test set, it would likely involve established laboratory methods such as culture or reference molecular assays for the target pathogens.
§ 866.3990 Gastrointestinal microorganism multiplex nucleic acid-based assay.
(a)
Identification. A gastrointestinal microorganism multiplex nucleic acid-based assay is a qualitativein vitro diagnostic device intended to simultaneously detect and identify multiple gastrointestinal microbial nucleic acids extracted from human stool specimens. The device detects specific nucleic acid sequences for organism identification as well as for determining the presence of toxin genes. The detection and identification of a specific gastrointestinal microbial nucleic acid from individuals exhibiting signs and symptoms of gastrointestinal infection aids in the diagnosis of gastrointestinal infection when used in conjunction with clinical evaluation and other laboratory findings. A gastrointestinal microorganism multiplex nucleic acid-based assay also aids in the detection and identification of acute gastroenteritis in the context of outbreaks.(b)
Classification. Class II (special controls). The special controls are set forth in FDA's guideline document entitled: “Class II Special Controls Guideline: Gastrointestinal Microorganism Multiplex Nucleic Acid-Based Assays for Detection and Identification of Microorganisms and Toxin Genes from Human Stool Specimens.” For availability of the guideline document, see § 866.1(e).