(62 days)
The BD ProbeTec™ Neisseria gonorrhoeae (GC) O* Amplified DNA Assay, when tested with the BD Viper™ System in Extracted Mode, uses Strand Displacement Amplification technology for the direct, qualitative detection of Neisseria gonorrhoeae DNA in clinician-collected female endocervical and male urethral swab specimens, patient-collected vaginal swab specimens (in a clinical setting), and male and female urine specimens (both UPT and Neat). The assay is also intended for use with gynecological specimens collected in PreservCyt® Solution using an aliquot that is removed prior to processing for additional gynecological testing. The assay is indicated for use with asymptomatic females and symptomatic males to aid in the diagnosis of gonococcal urogenital disease.
The BD Viper System, when used with the BD ProbeTec amplified nucleic assay(s), is intended for the in vitro detection of targeted organisms from specimens as identified in the assay-specific reagent package insert(s).
The BD ProbeTec GC Q* Amplified DNA Assay is based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescently-labeled detector probe. The reagents for SDA are dried in two separate disposable microwells: the Priming Microwell contains the amplification primers, fluorescently-labeled detector probe, nucleotides and other reagents necessary for amplification, while the Amplification Microwell contains the two enzymes (a DNA polymerase and a restriction endonuclease) that are required for SDA. The BD Viper TM System pipettes a portion of the purified DNA solution from each Extraction Tube into a Priming Microwell to rehydrate the contents. After a brief incubation, the reaction mixture is transferred to a corresponding, pre-warmed Amplification Microwell which is sealed to prevent contamination and then incubated in one of the two thermally-controlled fluorescent readers. The presence or absence of N. gonorrhoeae DNA is determined by calculating the peak fluorescence (Maximum Relative Fluorescent Units (MaxRFU)) over the course of the amplification process and by comparing this measurement to a predetermined threshold value.
In addition to the fluorescent probe used to detect amplified N. gonorrhoeae target DNA, a second labeled oligonucleotide is incorporated in each reaction. The Extraction Control (EC) oligonucleotide is labeled with a different dye than that used for detection of the N. gonorrhoeae -specific target and is used to confirm the validity of the extraction process. The EC is dried in the Extraction Tubes and is rehydrated upon addition of the specimen and extraction reagents. At the end of the extraction process, the EC fluorescence is monitored by the BD Viper System and an automated algorithm is applied to both the EC and N. gonorrhoeae -specific signals to report results as positive, negative, or EC failure.
The provided document describes the clinical performance and analytical characteristics of the BD ProbeTec™ Neisseria gonorrhoeae (GC) Q* Amplified DNA Assay.
Here's an analysis of the acceptance criteria and study details:
1. Table of Acceptance Criteria and Reported Device Performance:
The document doesn't explicitly state numeric "acceptance criteria" in a dedicated section with pass/fail thresholds. Instead, it presents the assay's performance characteristics. For this table, I will infer the implied acceptance standard is demonstrating high sensitivity and specificity for the detection of N. gonorrhoeae.
| Metric | Acceptance Criteria (Inferred) | Reported Device Performance (PreservCyt Specimens) |
|---|---|---|
| Overall Sensitivity | High (e.g., >90%) | 95.3% (41/43) |
| Overall Specificity | Very High (e.g., >95%) | 99.95% (2030/2031) |
| Symptomatic Sensitivity | High | 100.0% (17/17) |
| Symptomatic Specificity | Very High | 99.9% (707/708) |
| Asymptomatic Sensitivity | High | 92.3% (24/26) |
| Asymptomatic Specificity | Very High | 100.0% (1323/1323) |
| Limit of Detection (LOD) | Low (high analytical sensitivity) | 95% proportion positive at 50 cells/mL. |
| Interfering Substances | Minimal interference | No interference observed with common substances; glacial acetic acid + blood may cause EC failures or false negatives. |
| Reproducibility | Highly reproducible | 100.0% correct detection for all tested positive and negative samples at or above LOD; low variability (MaxRFU Standard Deviations) within and between runs/sites. |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size (Clinical Test Set): 2074 female subjects were evaluated with PreservCyt specimens. This was after excluding 2 subjects with undetermined patient infected status and 3 subjects without a PreservCyt specimen result from an initial 2079 compliant subjects.
- Data Provenance:
- Country of Origin: North America (specifically, eleven geographically diverse clinical sites).
- Retrospective or Prospective: The study was prospective, involving the collection of specimens from subjects attending family planning, OB/GYN, and sexually transmitted disease clinics. Subjects were classified as symptomatic or asymptomatic based on reported symptoms at the time of collection.
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 or qualifications of individual experts. The "ground truth" (Patient Infected Status, PIS) was established algorithmically based on the results of three reference methods performed on three randomized endocervical swab specimens. These reference methods were:
- BD ProbeTec ET CT/GC/AC assay
- BD ProbeTec GC Q assay
- Another commercially available NAAT (Nucleic Acid Amplification Test)
4. Adjudication Method for the Test Set:
The adjudication method for establishing the Patient Infected Status (PIS) was an algorithmic consensus method:
- PIS-Positive: At least two positive reference results were required.
- PIS-Negative: At least two negative reference results were required.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed or described. This assay is a diagnostic test performed by an automated system (BD Viper System), not an imaging device requiring human interpretation of results in a comparative effectiveness setting.
6. Standalone (Algorithm Only) Performance:
Yes, the study describes the standalone performance of the BD ProbeTec GC Q* Amplified DNA Assay. The clinical performance characteristics (sensitivity, specificity) are reported for the assay's results compared to the established patient infected status, without human-in-the-loop interpretation impacting the reported performance metrics of the device itself. The BD Viper System applies an automated algorithm to report results as positive, negative, or EC failure.
7. Type of Ground Truth Used:
The ground truth used was expert consensus (algorithmic) based on the results of multiple predicate/reference nucleic acid amplification tests (NAATs). Specifically, a Patient Infected Status (PIS) algorithm was used, requiring at least two positive or two negative results from three different reference NAATs to classify a subject as PIS-positive or PIS-negative, respectively. It is not pathology, or direct outcomes data, but rather a derived "patient infected status" based on highly sensitive and specific laboratory tests.
8. Sample Size for the Training Set:
The document does not provide information on the sample size used for the training set. Standard practice for such assays typically involves extensive internal development and optimization (which would constitute "training") but explicit details on a distinct "training set" are not always presented in 510(k) summaries, which often focus on formal validation data.
9. How the Ground Truth for the Training Set Was Established:
The document does not describe how the ground truth for any training set might have been established. As mentioned above, details about a separate "training set" are absent from this summary.
§ 866.3390
Neisseria spp. direct serological test reagents.(a)
Identification. Neisseria spp. direct serological test reagents are devices that consist of antigens and antisera used in serological tests to identifyNeisseria spp. from cultured isolates. Additionally, some of these reagents consist ofNeisseria spp. antisera conjugated with a fluorescent dye (immunofluorescent reagents) which may be used to detect the presence ofNeisseria spp. directly from clinical specimens. The identification aids in the diagnosis of disease caused by bacteria belonging to the genusNeisseria, such as epidemic cerebrospinal meningitis, meningococcal disease, and gonorrhea, and also provides epidemiological information on diseases caused by these microorganisms. The device does not include products for the detection of gonorrhea in humans by indirect methods, such as detection of antibodies or of oxidase produced by gonococcal organisms.(b)
Classification. Class II (performance standards).