BacT/ALERT® VIRTUO(TM) Microbial Detection System is an automated microbial test system capable of incubating, agitating, and continuously monitoring for the detection of aerobic microorganism growth from blood and other normally sterile body fluids.

Device Description

The VIRTUO Instrument is the next generation of the bioMerieux BacT/ALERT Microbial Detection System. This blood culture instrument consists of an incubator, agitation mechanism, robotic apparatus for automated loading and unloading of bottles and a tactile graphical interface. The VIRTUO is used in conjunction with existing, commercialized BacT/ALERT reagent bottles for clinical use (BacT/ALERT SA, SN, FA Plus, FN Plus and PF Plus culture bottles). The VIRTUO system utilizes a colorimetric sensor and reflected light to monitor the presence and production of carbon dioxide (CO2) dissolved in the culture medium. If microorganisms are present in the inoculated sample, carbon dioxide is produced as the organisms metabolize the substrates in the culture medium. When growth of the microorganisms produces CO2, the color of the gas-permeable sensor installed in the bottom of each culture bottle changes from blue-green to yellow. The color change results in an increase of reflectance units monitored by the system. The VIRTUO optically monitors the reflectance of each bottle over time and will store and interpret readings against algorithms, which are embedded in the firmware and/or software.

AI/ML Overview

Here's a breakdown of the BacT/ALERT VIRTUO Bacterial Detection System's acceptance criteria and study proving its performance, based on the provided FDA 510(k) Summary.

This device is not an AI/ML device in the modern sense (e.g., using deep learning for diagnostic imaging), but rather an automated system that uses embedded algorithms to detect microbial growth. Therefore, some of the requested information regarding AI/ML-specific concepts (like MRMC studies, training set details for complex models) might not be directly applicable or detailed in the provided document. The study performed is a comparative clinical study against a predicate device.

Device Name: BacT/ALERT® VIRTUO™ Microbial Detection System

Device Description: An automated microbial test system capable of incubating, agitating, and continuously monitoring for the detection of aerobic, facultative, and anaerobic microorganism growth from blood and other normally sterile body fluids. It utilizes a colorimetric sensor and reflected light to monitor CO2 production as an indicator of microbial growth. Its detection algorithms are proprietary to the system.

1. Table of Acceptance Criteria and Reported Device Performance

The provided document doesn't explicitly state the "acceptance criteria" for performance as a numerical threshold (e.g., "sensitivity must be > X%"). Instead, it demonstrates substantial equivalence to the predicate device (BacT/ALERT® 3D Microbial Detection System) by comparing their performance head-to-head. The key performance metric assessed is the "Ratio of True Positives" and its 95% Confidence Interval (CI), with the implicit acceptance being that the performance of the VIRTUO is comparable to the established predicate device, and the false positive/negative rates are within acceptable limits.

Performance Goal: Demonstrate substantial equivalence to the BacT/ALERT® 3D Microbial Detection System in detecting microbial growth.

Performance Metric	Acceptance Criteria (Implied)	Reported Device Performance (BacT/ALERT® VIRTUO™ vs. BacT/ALERT® 3D™)
Ratio of True Positives (VIRTUO / BTA3D) – Overall	95% CI for the ratio of true positives should largely encompass or be close to 1.0, indicating comparable detection rates between the two systems for various specimen types and clinical determinations (Significant, Contaminant, Unknown).	Blood Cultures (Compliant)
For FA Plus (Blood)	Ratio of True Positives should be close to 1.0, and 95% CI should indicate comparable performance.	Significant: 0.970 (95% CI: 0.821, 1.119)
		Contaminant: 0.636
		Total: 0.924 (95% CI: 0.766, 1.082)
For FN Plus (Blood)	Same as above.	Significant: 0.979 (95% CI: 0.823, 1.135)
		Contaminant: 1.300
		Total: 1.034 (95% CI: 0.852, 1.216)
For PF Plus (Blood)	Due to low numbers, potentially wider CIs are accepted, but still demonstrate detection.	Significant: 1.000 (95% CI: -1.772, 3.772*)
		Total: 1.000 (95% CI: -1.772, 3.772*)
For Low Fill FA Plus (Blood)	Same as above.	Significant: 0.966 (95% CI: 0.790, 1.142)
		Contaminant: 1.333
		Total: 1.031 (95% CI: 0.790, 1.272)
For SA (Blood)	Same as above.	Significant: 1.026 (95% CI: 0.857, 1.195)
		Contaminant: 0.400
		Total: 0.920 (95% CI: 0.736, 1.104)
For SN (Blood)	Same as above.	Significant: 1.067 (95% CI: 0.797, 1.337)
		Contaminant: 0.250
		Total: 1.000 (95% CI: 0.730, 1.270)
Sterile Body Fluid Cultures
For FA Plus (SBF)	Same as above.	Significant: 1.000 (95% CI: 0.852, 1.148)
		Contaminant: 1.333
		Total: 1.058 (95% CI: 0.864, 1.252)
For FN Plus (SBF)	Same as above.	Significant: 1.026 (95% CI: 0.838, 1.214)
		Contaminant: 1.125
		Total: 1.000 (95% CI: 0.794, 1.206)
For PF Plus (SBF)	Same as above.	Significant: 0.933 (95% CI: 0.807, 1.059)
		Contaminant: 0.000
		Total: 0.882 (95% CI: 0.665, 1.099)
For SA (SBF)	Same as above.	Significant: 1.000 (95% CI: 0.837, 1.163)
		Contaminant: 1.000
		Total: 1.056 (95% CI: 0.806, 1.306)
False Positive Rate (Overall)	Should be low and comparable to the predicate device.	VIRTUO: 0.09% (5/5862)
		BTA3D: 0.19% (11/5862)
False Negative Rate (Overall)	Should be low and comparable to the predicate device.	VIRTUO: 0.38% (22/5862)
		BTA3D: 0.38% (22/5862)
Positive Control Performance	High percentage of positive controls detected.	1487/1490 (99.8%) signaled positive.
Negative Control Performance	High percentage of negative controls detected as negative.	1486/1486 (100%) signaled negative.
Overall Control Performance	High percentage of controls giving expected results.	2973/2976 (99.9%) of controls gave expected results.

Note on CI for PF Plus (Blood): The document explicitly states "Since the confidence interval contains a negative, the interval does not provide a meaningful interpretation" due to extremely low positive counts for this specific category. However, the 1:1 ratio of detected positives itself implies equivalence for the limited positive cases observed.

2. Sample Size Used for the Test Set and Data Provenance

Test Set (Clinical Evaluation):
- Total Bottle Pairs Tested (Clinical Samples): 5862 bottle pairs (one VIRTUO bottle and one BTA3D bottle per patient sample).
- Detailed Sample Sizes per Category:
  - BacT/ALERT FA Plus (Blood): 1057 (compliant)
  - BacT/ALERT FN Plus (Blood): 912 (compliant)
  - BacT/ALERT PF Plus (Blood): 161 (compliant)
  - Low Fill BacT/ALERT FA Plus (Blood): 379 (compliant)
  - BacT/ALERT SA (Blood): 780 (compliant)
  - BacT/ALERT SN (Blood): 830 (compliant)
  - BacT/ALERT FA Plus (SBF): 374
  - BacT/ALERT FN Plus (SBF): 437
  - BacT/ALERT PF Plus (SBF): 77
  - BacT/ALERT SA (SBF): 81
  - BacT/ALERT SN (SBF): 81
- Data Provenance: "External performance evaluations were conducted at eight external clinical sites." The document does not specify the country of origin, but given the FDA submission, it is typically either US-based or multi-national with significant US participation. The data is prospective as it involves clinical evaluation performed specifically for the 510(k) submission.
Control Sample Size:
- 1490 positive controls
- 1486 negative controls
- Total controls: 2976

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The document does not specify the number or qualifications of experts used. However, for a device detecting microbial growth, the "ground truth" for positive culture would typically be established by standard microbiological laboratory procedures:

Positive Culture: Visual detection of growth indicators (e.g., turbidity, gas production, or color change) in the culture bottle, followed by subculture onto agar plates and identification of microbial isolates using standard laboratory techniques (e.g., Gram stain, biochemical tests, mass spectrometry).
Negative Culture: No growth detected after a specified incubation period, confirmed by terminal subculture on rich media.
Clinical Determination (Significant/Contaminant/Unknown): This classification would typically be made by a qualified microbiologist or infectious disease physician, based on the identified organism, patient's clinical presentation, and other relevant factors.

4. Adjudication Method (e.g., 2+1, 3+1, none) for the Test Set

The document does not explicitly describe an adjudication method. For comparison studies of this nature, discrepancies between the investigational device and the predicate (or deviations from expected results) would generally be investigated by the clinical sites' microbiology laboratories to determine the definitive "ground truth" (e.g., re-subculture, review of patient charts).

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

No, an MRMC comparative effectiveness study was not done. This type of study (assessing human reader performance with and without AI assistance on diagnostic images) is not applicable to this device. The BacT/ALERT VIRTUO is an automated microbial detection system, not an imaging AI diagnostic aid for human readers. Its primary function is to automatically detect the presence of microbial growth, replacing or assisting a manual observation process, rather than augmenting a radiologist's interpretation of an image.

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

Yes, in essence, the primary performance evaluation measures the standalone performance of the BacT/ALERT VIRTUO system against the predicate BacT/ALERT 3D system. Both systems operate autonomously to detect microbial growth. The reported "True Positives," "False Positives," and "False Negatives" for VIRTUO directly reflect its algorithm-only performance in detecting growth from clinical samples, without human intervention required for the detection itself (humans are involved in loading bottles and interpreting the overall clinical significance, but not in the detection of growth by the device).

7. The Type of Ground Truth Used (expert consensus, pathology, outcomes data, etc.)

The ground truth was established by standard microbiological culture and identification methods, combined with a clinical review to classify isolates as "significant," "contaminant," or "unknown." This is essentially a definitive laboratory diagnosis of microbial presence and identity.

8. The Sample Size for the Training Set

The document does not specify a separate "training set" sample size in the context of typical AI/ML model development. The device uses "proprietary algorithms unique for BacT/ALERT VIRTUO," which implies embedded logic or rules rather than a dynamically trained machine learning model in the contemporary sense. The algorithms would have been developed and validated internally by the manufacturer using a combination of laboratory studies, simulated data, and potentially a distinct internal dataset. The data presented in the 510(k) is for the clinical validation (test set performance) of the final device.

9. How the Ground Truth for the Training Set was Established

Given that this is not a modern AI/ML device with a distinct training phase documented for public review, the methods for establishing ground truth for any internal algorithm development ("training") would also implicitly rely on controlled laboratory studies and established microbiological techniques to generate data on microbial growth, CO2 production kinetics, and associated reflectance changes. This would involve inoculating bottles with known strains and concentrations of microorganisms and observing their growth characteristics under various conditions.

Summary

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Food and Drug Administration 10903 New Hampshire Avenue Document Control Center - WO66-G609 Silver Spring, MD 20993-0002

March 28, 2017

BIOMERIEUX, INC. JOLYN TENLLADO DIRECTOR GLOBAL REGULATORY AFFAIRS MICROBIOLOGY 595 ANGLUM RD. HAZELWOOD MO 63042

Re: K161816

Trade/Device Name: BacT/ALERT® VIRTUO™ Microbial Detection System Regulation Number: 21 CFR 866.2560 Regulation Name: Microbial growth monitor Regulatory Class: I Product Code: MDB Dated: February 21, 2017 Received: February 23, 2017

Dear Ms. Tenllado:

We have reviewed your Section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food. Drug. and Cosmetic Act (Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21. Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Parts 801 and 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR 803); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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If you desire specific advice for your device on our labeling regulations (21 CFR Parts 801 and 809), please contact the Division of Industry and Consumer Education at its toll-free number (800) 638 2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/Resourcesfor You/Industry/default.htm. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to

http://www.fda.gov/MedicalDevices/Safety/ReportaProblem/default.htm for the CDRH's Office of Surveillance and Biometrics/Division of Postmarket Surveillance.

You may obtain other general information on your responsibilities under the Act from the Division of Industry and Consumer Education at its toll-free number (800) 638-2041 or (301) 796-7100 or at its Internet address

http://www.fda.gov/MedicalDevices/ResourcesforYou/Industry/default.htm.

Sincerely yours,

Ribhi Shawar -A

For Uwe Scherf, M.Sc., Ph.D. Director Division of Microbiology Devices Office of In Vitro Diagnostics and Radiological Health Center for Devices and Radiological Health

Enclosure

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1.5 - Indications for Use (FDA FORM 3881)

DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration

Indications for Use

Form Approved: OMB No. 0910-0120 Expiration Date: January 31, 2017 See PRA Statement below.

510(k) Number (if known) Unknown at time of 510(k) Submission

Device Name BacT/ALERT® VIRTUO(TM) Microbial Detection System

Indications for Use (Describe)

Type of Use (Select one or both, as applicable)
Prescription Use (Part 21 CFR 801 Subpart D)	Over-The-Counter Use (21 CFR 801 Subpart C)

CONTINUE ON A SEPARATE PAGE IF NEEDED.

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Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov

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Image /page/3/Picture/1 description: The image shows the logo for bioMérieux. The logo consists of the company name in a sans-serif font, with a stylized graphic above it. The graphic is a circle with lines on the left side, and a curved line that goes through the circle.

510(k) SUMMARY

BacT/ALERT® VIRTUO™ Microbial Detection System

510(k) Submission Information:

Submitter's Name:	bioMérieux, Inc.
Address:	595 Anglum RoadHazelwood, MO 63042
Contact Person:	Jolyn TenlladoDirector, Global Regulatory Affairs Microbiology
Phone Number:	314-731-8386
Fax Number:	314-731-8689
Date of Preparation:	June 30, 2016
Device Name:
Formal/Trade Name:	BacT/ALERT® VIRTUO™ Microbial DetectionSystem
Classification Name:	21 CFR 866.2560, Microbial Growth Monitor
Common Name:	BacT/ALERT® VIRTUO™; VIRTUO™
Predicate Device:	BacT/ALERT® 3D Microbial Detection System(K903505/A2)

D. 510(k) Summary:

Intended Use:

BacT/ALERT® VIRTUO™ Microbial Detection System is an automated microbial test system capable of incubating, agitating, and continuously monitoring for the detection of aerobic, facultative, and anaerobic microorganism growth from blood and other normally sterile body fluids.

Device Description:

Page 001 - 1.10-1

bioMérieux, Inc. Phone: 314/731-8500 800/638-4835 595 Anglum Road, Hazelwood, Missouri 63042-2320, USA Fax: 314/731-8700

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The VIRTUO system utilizes a colorimetric sensor and reflected light to monitor the presence and production of carbon dioxide (CO2) dissolved in the culture medium. If microorganisms are present in the inoculated sample, carbon dioxide is produced as the organisms metabolize the substrates in the culture medium. When growth of the microorganisms produces CO2, the color of the gas-permeable sensor installed in the bottom of each culture bottle changes from blue-green to yellow. The color change results in an increase of reflectance units monitored by the system. The VIRTUO optically monitors the reflectance of each bottle over time and will store and interpret readings against algorithms, which are embedded in the firmware and/or software.

	New Device:BacT/ALERT VIRTUO	Predicate Device:BacT/ALERT 3D
Similarities
Intended Use	The BacT/ALERT® VIRTUOTMMicrobial Detection System isan automated microbial testsystem capable of incubating,agitating, and continuouslymonitoring for the detection ofaerobic, facultative, andanaerobic microorganismgrowth from blood and othernormally sterile body fluids.Note: The intial release of thesystem will not include detectionof Mycobacterium speciesgrowth from clinical specimens.	The BacT/ALERT® 3D MicrobialDetection System is a totallyautomated test system capableof incubating, agitating, andcontinuously monitoring aerobicand anaerobic media inoculatedwith patient specimenssuspected of having bacteremia,fungemia, and/ormycobacteremia (Clinical Use)
Reagent	For use with the BacT/ALERTSA, SN, FA Plus, PF Plus andFN Plus culture bottles (ClinicalUse)	For use with the BacT/ALERTSA, SN, FA, PF, FN, MP, FAPlus, FN Plus, PF Plus (ClinicalUse)
Detection Methodfor MicrobialGrowth	Reflectance change ofcolorimetric sensor over time tomeasure metabolic reactants	Reflectance change ofcolorimetric sensor over time tomeasure metabolic reactants
Incubation &Agitation	Electrically heated forced airconvection incubation.Continuous 12.5° fromhorizontal sinusoidal rocking ofreagent & sample @50-60cycles/minute.	Electrically heated forced airconvection incubation.Continuous 12.5° fromhorizontal sinusoidal rocking ofreagent & sample @50-60cycles/minute.
ColorimetricOptics	LED emitter with 634nm peakwavelength and 17nmbandwidth/photodiode detector.Four point graduated grey scaleoptical calibration.	LED emitter with 634nm peakwavelength and 17nmbandwidth/photodiode detector.Four point graduated grey scaleoptical calibration.
Differences
Detectionalgorithms	Proprietary algorithms uniquefor BacT/ALERT VIRTUO	Proprietary algorithms uniquefor BacT/ALERT 3D
Capacity	108-6912 bottles	240-1440 bottles
Bottle Loading	Automated loading of bottlesplaced on conveyor (up to 40 ata time) with bottle labelscanning, measuring of sample	Customer scans bottle labelsand loads the bottle into a bottlecell of an open drawer, onebottle at a time

Table 1: Similarities & Differences Between BacT/ALERT Microbial Detection Systems
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Section 1.10

	volume & loading via roboticarm into open incubator cell withappropriate agitation. Customercan manually load bottles ifautomation features are notoperable
RemoteCustomer Access	Internal (customer site) networkaccess	Unavailable

Performance Characteristics:

The BacT/ALERT VIRTUO Microbial Detection System demonstrated substantially equivalent performance when compared with the BacT/ALERT 3D Microbial Detection System. This 510(k) Premarket Notification presents data in support of the BacT/ALERT VIRTUO. External performance evaluations were conducted at eight external clinical sites. The evaluation included testing of blood & sterile body fluids using the BacT/ALERT SA, SN, FA Plus, PF Plus and FN Plus culture bottles with the VIRTUO and 3D Systems.

The following tables compare results of the BacT/ALERT VIRTUO to BacT/ALERT 3D blood cultures for all compliant blood culture bottles that yielded any number of isolates on subculture.

Clinical Determination	VIRTUO TruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Significant	64	6.1 (64/1057)	66	6.2 (66/1057)	0.970	0.821,1.119
Contaminant	7	0.7 (7/1057)	11	1.0 (11/1057)	0.636
Unknown	2	0.2 (2/1057)	2	0.2 (2/1057)	1.000
Total	73	6.9 (73/1057)	79	7.5 (79/1057)	0.924	0.766,1.082

BacT/ALERT FA Plus: Blood - Compliant -- Single and Multiple Isolates
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BacT/ALERT FN Plus: Blood - Compliant - Single and Multiple Isolates

Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3DTruePositives	% of BTA3D TruePositives inPopulation	Ratio ofTruePositives	95% CI(LCL,UCL)
Significant	47	5.2 (47/912)	48	5.3 (48/912)	0.979	0.823,1.135
Contaminant	13	1.4 (13/912)	10	1.1 (10/912)	1.300
Unknown	0	0.0 (0/912)	0	0.0 (0/912)	-
Total	60	6.6 (60/912)	58	6.4 (58/912)	1.034	0.852,1.216

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			BacT/ALERT PF Plus: Blood - Compliant - Single and Multiple Isolates

Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Significant	1	0.6 (1/161)	1	0.6 (1/161)	1.000	-1.772,3.772*
Contaminant	0	0.0 (0/161)	0	0.0 (0/161)	-
Unknown	0	0.0 (0/161)	0	0.0 (0/161)	-
Total	1	0.6 (1/161)	1	0.6 (1/161)	1.000	-1.772,3.772*

*Since the confidence interval contains a negative, the interval does not pe interval does not provide a meaningful interpretation.

Low Fill BacT/ALERT FA Plus: Blood – Compliant – Single and Multiple Isolates

Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL,UCL)
Significant	28	7.4 (28/379)	29	7.7 (29/379)	0.966	0.790,1.142
Contaminant	4	1.1 (4/379)	3	0.8 (3/379)	1.333
Unknown	1	0.3 (1/379)	0	0.0 (0/379)	-
Total	33	8.7 (33/379)	32	8.4 (32/379)	1.031	0.790,1.272

BacT/ALERT SA: Blood Culture – Compliant – Single and Multiple Isolates

Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Significant	40	5.1 (40/780)	39	5.0 (39/780)	1.026	0.857,1.195
Contaminant	4	0.5 (4/780)	10	1.3 (10/780)	0.400
Unknown	2	0.3 (2/780)	1	0.1 (1/780)	2.000
Total	46	5.9 (46/780)	50	6.4 (50/780)	0.920	0.736,1.104

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Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Significant	32	3.9 (32/830)	30	3.6 (30/830)	1.067	0.797,1.337
Contaminant	1	0.1 (1/830)	4	0.5 (4/830)	0.250
Unknown	1	0.1 (1/830)	0	0.0 (0/830)	-
Total	34	4.1 (34/830)	34	4.1 (34/830)	1.000	0.730,1.270

BacT/ALERT SN: Blood – Compliant – Single and Multiple Isolates

The following tables compare results of the BacT/ALERT VIRTUO to BacT/ALERT 3D sterile body fluid cultures that yielded single or multiple isolates on subculture.

Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Significant	42	11.2 (42/374)	42	11.2 (42/374)	1.000	0.852,1.148
Contaminant	8	2.1 (8/374)	6	1.6 (6/374)	1.333
Unknown	5	1.3 (5/374)	4	1.1 (4/374)	1.250
Total	55	14.7 (55/374)	52	13.9 (52/374)	1.058	0.864,1.252

BacT/ALERT FA Plus: SBF - Single and Multiple Isolates

BacT/ALERT FN Plus: SBF - Single and Multiple Isolates

	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL, UCL)
Clinical Determination
Significant	39	8.9 (39/437)	38	8.7 (38/437)	1.026	0.838,1.214
Contaminant	9	2.1 (9/437)	8	1.8 (8/437)	1.125
Unknown	4	0.9 (4/437)	6	1.4 (6/437)	0.667
Total	52	11.9 (52/437)	52	11.9 (52/437)	1.000	0.794,1.206

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Clinical Determination	VIRTUOTruePositives	% of VIRTUO TruePositives inPopulation	BTA3D TruePositives	% of BTA3D TruePositives inPopulation	Ratio of TruePositives	95% CI(LCL,UCL)
Significant	14	18.2 (14/77)	15	19.5 (15/77)	0.933	0.807,1.059
Contaminant	0	0.0 (0/77)	2	2.6 (2/77)	0.000
Unknown	1	1.3 (1/77)	0	0.0 (0/77)	-
Total	15	19.5 (15/77)	17	22.1 (17/77)	0.882	0.665,1.099

BacT/ALERT SA: Sterile Body Fluids - Single and Multiple Isolates

BacT/ALERT SN: Sterile Body Fluids - Single and Multiple Isolates

Clinical Determination	VIRTUO True Positives	% of VIRTUO True Positives in Population	BTA3D True Positives	% of BTA3D True Positives in Population	Ratio of True Positives	95% CI (LCL, UCL)
Significant	17	21.0 (17/81)	17	21.0 (17/81)	1.000	0.837,1.163
Contaminant	1	1.2 (1/81)	1	1.2 (1/81)	1.000
Unknown	1	1.2 (1/81)	0	0.0 (0/81)	-
Total	19	23.5 (19/81)	18	22.2 (18/81)	1.056	0.806,1.306

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Section 1.10

When all 5862 bottle pairs tested are considered, false positive rates were 0.09% (5/5862) and 0.19% (11/5862) for VIRTUO and BTA3D, respectively. False negative rates were 0.38% (22/5862) and 0.38% (22/5862) for VIRTUO and BTA3D, respectively, While the algorithm on VIRTUO is new and has some differences compared to that of the BTA3D, these results for VIRTUO and BTA3D demonstrate an equivalent ability of the two systems to detect and recover organisms in BacT/ALERT bottles and demonstrate the efficacy of the VIRTUO Detection algorithm. The yields of microorganisms are similar between VIRTUO and BTA3D.

There were 1490 positive controls tested on VIRTUO for all sites combined. Of those, 1487 (99.8%) were signaled positive by VIRTUO. There were 1486 negative controls tested for all sites combined. Of those, 1486 (100%) were signaled negative by VIRTUO. Of the total of 2976 controls tested over the course of the clinical trial, VIRTUO gave the expected result for 2973/2976 (99.9%) of the controls.

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Regulation Number and Section

§ 866.2560 Microbial growth monitor.

(a)
Identification. A microbial growth monitor is a device intended for medical purposes that measures the concentration of bacteria suspended in a liquid medium by measuring changes in light scattering properties, optical density, electrical impedance, or by making direct bacterial counts. The device aids in the diagnosis of disease caused by pathogenic microorganisms.(b)
Classification. Class I. With the exception of automated blood culturing system devices that are used in testing for bacteria, fungi, and other microorganisms in blood and other normally sterile body fluids, this device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter.