(370 days)
The SeraQuest HSV Type 2 Specific IgG assay is an enzyme-linked immunosorbent assay (ELISA) intended for the qualitative detection of human IgG antibodies to type 2 herpes simplex virus (HSV) in human serum. The test is indicated for sexually active individuals and expectant mothers as an aid in the presumptive diagnosis of HSV-2 infection. The predictive value of a positive or negative result depends on the prevalence of HSV-2 infection in the pre-test likelihood of HSV-2 infection.
The test is not FDA cleared for screening blood or plasma donors. The performance of this assay has not been established for immunocompromised patients, pediatric patients or matrices other than human serum.
The SeraQuest® HSV Type 2 Specific IgG test is a solid-phase enzyme-linked immunoassay (ELISA), which is performed in microwells, at room temperature, and in three thirty-minute incubations. The test detects IgG antibodies which are directed against HSV 2 type-specific antigens in human serum. The Calibrator in the SeraQuest® HSV Type 2 Specific IgG test set has been assigned Index values based on an in-house standard. Test results are reported as Index values.
This document describes the performance of the SeraQuest® HSV Type 2 Specific IgG assay when performed on the ChemWell® Automated Analyzer, comparing it to the previously cleared manual method.
Here's the breakdown of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state numerical acceptance criteria in a dedicated section. However, the "Method Comparison Study" presents the core performance metrics (Positive Percent Agreement and Negative Percent Agreement) against the predicate device. For the purpose of this response, we infer that high agreement with the predicate device is the acceptance criterion.
| Acceptance Criterion (Inferred from Study Design) | Reported Device Performance (ChemWell Automated Analyzer vs. Manual Method) |
|---|---|
| High Positive Percent Agreement (PPA) with predicate device | 100% (125/125) |
| High Negative Percent Agreement (NPA) with predicate device | 99.01% (100/101) |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size for Test Set: 226 samples.
- Data Provenance: Samples were developed from "remnants of patient samples and samples from vendors." Additional samples were prepared by spiking negative samples with positive samples or dilution with diluent reagent to span the range of the assay's measuring interval. The country of origin is not specified, but it can be inferred as being related to the applicant's location (Palm City, Florida, USA). The study appears to be a retrospective evaluation using existing or manufactured samples.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The ground truth for the test set was established by comparison against a predicate device (manual method), not by independent expert interpretation. Therefore, experts were not explicitly used to establish the ground truth for this device in the context of this study. The "ground truth" here is the result obtained from the established manual method.
4. Adjudication Method for the Test Set
No adjudication method using multiple readers or experts is described, as the comparison is between two automated/semi-automated assay methods (the new device vs. the predicate). The "truth" for the comparison was the result generated by the manual method.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done. This study focuses on the equivalence of an automated assay to a manual assay, not on human reader performance.
6. Standalone (Algorithm Only) Performance
Yes, a standalone comparison was done. The study directly compares the performance of the "SeraQuest® HSV Type 2 Specific IgG assay performed by ChemWell® Automated Analyzer" (the new device) against the "SeraQuest® HSV Type 2 Specific IgG assay performed by Manual Method" (the predicate device). This evaluates the algorithm/device performance independently of human interpretation, focusing on concordance between the two methods.
7. Type of Ground Truth Used
The type of ground truth used was comparison to a predicate device (manual assay results). This means the "truth" for evaluating the automated analyzer was the result provided by the already cleared manual method.
8. Sample Size for the Training Set
The document does not explicitly mention a separate training set or its sample size. The study focuses on verifying the performance of the automated analyzer against the predicate manual method using the 226 samples for method comparison and additional samples for precision studies.
9. How the Ground Truth for the Training Set Was Established
Since a separate training set is not explicitly described, the method for establishing its ground truth is also not detailed. The validation approach is based on demonstrating equivalence to an existing, cleared method.
§ 866.3305 Herpes simplex virus serological assays.
(a)
Identification. Herpes simplex virus serological assays are devices that consist of antigens and antisera used in various serological tests to identify antibodies to herpes simplex virus in serum. Additionally, some of the assays consist of herpes simplex virus antisera conjugated with a fluorescent dye (immunofluorescent assays) used to identify herpes simplex virus directly from clinical specimens or tissue culture isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by herpes simplex viruses and provides epidemiological information on these diseases. Herpes simplex viral infections range from common and mild lesions of the skin and mucous membranes to a severe form of encephalitis (inflammation of the brain). Neonatal herpes virus infections range from a mild infection to a severe generalized disease with a fatal outcome.(b)
Classification. Class II (special controls). The device is classified as class II (special controls). The special control for the device is FDA's revised guidance document entitled “Class II Special Controls Guidance Document: Herpes Simplex Virus Types 1 and 2 Serological Assays.” For availability of the guidance revised document, see § 866.1(e).