(88 days)
The Solana® HSV 1+2/VZV Assay is an in vitro diagnostic test, using isothermal amplification technology (helicase-dependent amplification, HDA), for the qualitative detection and differentiation of herpes simplex virus type 1, herpes simplex virus type 2, and varicella-zoster virus DNA isolated and purified from cutaneous or mucocutaneous lesion samples obtained from symptomatic patients suspected of active herpes simplex virus 1, herpes simplex virus 2 and/or varicella-zoster infection. The Solana® HSV 1+2/VZV Assay is intended to aid in the diagnosis of herpes simplex virus 1, herpes simplex virus 2 and varicella-zoster virus active cutaneous or mucocutaneous infections. Negative results do not preclude herpes simplex virus 1, herpes simplex virus 2 and varicella-zoster virus infections and should not be used as the sole basis for diagnosis, treatment or other management decisions. The Solana® HSV 1+2/VZV Assay is intended for use only with the Solana® instrument.
Warning: The Solana® HSV 1 + 2/VZV Assay is not intended for use with cerebrospinal fluid or to aid in the diagnosis of HSV or VZV infections of the central nervous system (CNS). The Solana® HSV 1 + 2/VZV Assay is not intended for use in prenatal screening.
The Solana® HSV 1+2/VZV Assay amplifies and detects viral DNA isolated from cutaneous or mucocutaneous lesion samples obtained from symptomatic patients suspected of active herpes simplex virus 1, herpes simplex virus 2 and/or varicella-zoster infection.
The assay consists of two (2) major steps: 1) specimen preparation, and 2) amplification and detection of target sequence specific to HSV-1, HSV-2 and/or VZV using isothermal Helicase-Dependent Amplification (HDA) in the presence of target-specific fluorescence probe.
Patient specimen is transferred to a Process Tube, subjected to heat treatment at 95°C for 5 minutes and mixed and vortexed. The processed sample is transferred to a Reaction Tube and mixed. The Reaction Tube contains lyophilized HDA reagents, dNTPs, primers and probes. Once rehydrated with the diluted sample, the Reaction Tube is placed in Solana for amplification and detection of specific target sequence. In Solana, the target sequences are amplified by HSV-1, HSV-2 and/or VZV specific primers and detected by HSV-1, HSV-2 and/or VZV specific fluorescence probes included in the Reaction Tube. A competitive process control (PRC) is included in the Process Tube to monitor sample processing, inhibitory substances in clinical samples, reagent failure or device failure. The PRC target is amplified by specific primers and detected by a PRC specific fluorescence probe.
The target and PRC probes are labeled with a quencher on one end and a fluorophore on the other end. In addition, the target and PRC probes carry a ribonucleic acid. Upon annealing to HSV-1, HSV-2, VZV or PRC amplicons, the fluorescence probes are cleaved by RNaseH2 and the fluorescence signal increases due to physical separation of fluorophore from quencher. Solana measures and interprets the fluorescent signal, using on-board method-specific algorithms. Solana will then report the test results to the user on its display screen, and the results can be printed via an attached printer.
{
"1. A table of acceptance criteria and the reported device performance": {
"HSV-1 Cutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 85.1% to 100%)",
"Specificity": "97.8% (95% CI: 95.0% to 99.1%)"
}
},
"HSV-2 Cutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "92.3% (95% CI: 75.9% to 97.9%)",
"Specificity": "94.4% (95% CI: 90.8% to 96.6%)"
}
},
"VZV Cutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 85.1% to 100%)",
"Specificity": "96.5% (95% CI: 93.0% to 98.3%)"
}
},
"HSV-1 Mucocutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 96.7% to 100%)",
"Specificity": "96.4% (95% CI: 94.0% to 97.8%)"
}
},
"HSV-2 Mucocutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "99.1% (95% CI: 95.0% to 99.8%)",
"Specificity": "97.2% (95% CI: 95.4% to 98.3%)"
}
},
"VZV Mucocutaneous Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 51.0% to 100%)",
"Specificity": "98.6% (95% CI: 96.9% to 99.4%)"
}
},
"HSV-1 Uncategorized Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 86.7% to 100%)",
"Specificity": "97.6% (95% CI: 93.1% to 99.2%)"
}
},
"HSV-2 Uncategorized Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 82.4% to 100%)",
"Specificity": "96.6% (95% CI: 92.3% to 98.6%)"
}
},
"VZV Uncategorized Lesions": {
"Acceptance Criteria": {
"Sensitivity": "≥ 85%",
"Specificity": "≥ 95%"
},
"Reported Device Performance": {
"Sensitivity": "100% (95% CI: 81.6% to 100%)",
"Specificity": "94.1% (95% CI: 87.8% to 97.3%)"
}
}
},
"2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)": {
"Total Sample Size": "1062 fresh lesion specimens (combined Cutaneous, Mucocutaneous, and Uncategorized)",
"Data Type": "Prospective study",
"Country of Origin": "United States (three sites across the United States)",
"Specific Sample Sizes by Lesion Type for Clinical Performance": {
"Cutaneous Lesions (HSV-1)": "249 specimens",
"Cutaneous Lesions (HSV-2)": "275 specimens",
"Cutaneous Lesions (VZV)": "222 specimens",
"Mucocutaneous Lesions (HSV-1)": "501 specimens",
"Mucocutaneous Lesions (HSV-2)": "610 specimens",
"Mucocutaneous Lesions (VZV)": "372 specimens",
"Uncategorized Lesions (HSV-1)": "148 specimens",
"Uncategorized Lesions (HSV-2)": "166 specimens",
"Uncategorized Lesions (VZV)": "119 specimens"
}
},
"3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)": "Not specified. The ground truth was established by comparator methods (ELVIS cell culture system for HSV-1/2 and H&V mixed cells with DFA for VZV), which are FDA-cleared laboratory methods, rather than expert consensus on images or other forms of data typically requiring expert review.",
"4. Adjudication method (e.g. 2+1, 3+1, none) for the test set": "For discrepant results between the Solana assay and the primary comparator method, an additional RT-PCR assay was used for secondary adjudication. The document notes how many of the discrepant cases were resolved by this additional RT-PCR assay (e.g., 'Three (3) of the five (5) positives was positive by an additional RT-PCR assay' for HSV-1 cutaneous lesions). This indicates a form of adjudication involving a third, independent test.",
"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": "Not applicable. This is a molecular diagnostic assay, not an imaging device that uses AI for interpretation by human readers. The clinical study compares the device's performance against established laboratory methods.",
"6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done": "Yes, a standalone study was conducted. The Solana® HSV 1+2/VZV Assay is an in vitro diagnostic test that processes specimens and provides results using on-board method-specific algorithms on the Solana® instrument. The reported performance characteristics (clinical sensitivity and specificity) are for the device operating as a standalone system against the comparator methods.",
"7. The type of ground truth used (expert concensus, pathology, outcomes data, etc)": "Laboratory comparator methods: ELVIS cell culture system for HSV-1 and HSV-2, and H&V mixed cells with DFA cell culture systems for VZV. Discrepancies were resolved using an additional RT-PCR assay.",
"8. The sample size for the training set": "Not explicitly stated for a distinct training set. The descriptions focus on the performance evaluation of the final device. For analytical performance (e.g., LOD, cross-reactivity, interference), contrived samples and specific strains were used for testing, but these are not referred to as a 'training set' in the context of machine learning. Clinical studies used fresh lesion specimens as described in section 2.",
"9. How the ground truth for the training set was established": "Not applicable, as a distinct training set (in the machine learning sense) with established ground truth is not described for this diagnostic device. Analytical sensitivities (LOD) were determined using quantified viral cultures (TCID50/mL), which would serve as a 'truth' for analytical performance testing."
}
§ 866.3309 Herpes virus nucleic acid-based cutaneous and mucocutaneous lesion panel.
(a)
Identification. A herpes virus nucleic acid-based cutaneous and mucocutaneous lesion panel is a qualitative in vitro diagnostic device intended for the simultaneous detection and differentiation of different herpes viruses in cutaneous and mucocutaneous lesion samples from symptomatic patients suspected of Herpetic infections. Negative results do not preclude infection and should not be used as the sole basis for treatment or other patient management decisions. The assay is not intended for use in cerebrospinal fluid samples.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Premarket notification submissions must include detailed documentation for the device description, including the device components, ancillary reagents required but not provided, and a detailed explanation of the methodology including primer design and selection.
(2) Premarket notification submissions must include detailed documentation from the following analytical and clinical performance studies: Analytical sensitivity (Limit of Detection), reactivity, inclusivity, precision, reproducibility, interference, cross reactivity, carry-over, and cross contamination.
(3) Premarket notification submissions must include detailed documentation of a clinical study using lesion samples in which Herpes Simplex Virus 1, Herpes Simplex Virus 2, or Varicella Zoster Virus DNA detection was requested. The study must compare the device performance to an appropriate well established reference method.
(4) A detailed explanation of the interpretation of results and acceptance criteria must be included in the device's 21 CFR 809.10(b)(9) compliant labeling.
(5) The device labeling must include a limitation statement that reads: “The device is not intended for use with cerebrospinal fluid or to aid in the diagnosis of HSV or VZV infections of the central nervous system (CNS).”
(6) Premarket notification submissions must include quality assurance protocols and a detailed documentation for device software, including, but not limited to, standalone software applications and hardware-based devices that incorporate software.
(7) The risk management activities performed as part of the manufacturer's 21 CFR 820.30 design controls must document an appropriate end user device training program that will be offered as part of efforts to mitigate the risk of failure to correctly operate the instrument.