Vstrip® H.pylori Antigen Rapid Test is a single use immunochromatographic assay for the qualitative detection of H. pylori antigen in unpreserved human stool specimens. Test results are intended to aid in the initial diagnosis and treatment of H. pylori infection. Test results should be taken into consideration by the physician in conjunction with the patient history and symptoms.

Device Description

The Vstrip® H.pylori Antigen Rapid Test (Vstrip®) is a Helicobacter pylori (H. pylori) antigen rapid test. It is a lateral flow immunochromatographic assay which employs antibody-coated latex beads to detect H. pylori antigens in stool specimens from patients suspected of H. pylori infection. This test is an in vitro diagnostic device to be used for the qualitative detection of H. pylori antigen in human stool samples, and test results are intended to aid in the diagnosis and treatment of H. pylori infection. This test utilizes a pair of H. pylori-specific monoclonal antibodies that are capable of detecting H.pylori antigens in human stool. The assay kit includes a foil pouch containing test cassette which houses a strip incorporated with a pair of H. pylori-specific monoclonal antibodies, sample preparation tubes that contain sample diluent buffer for dilution of stool sampler tool attached to the underside of the tube cap and a dispenser tool attached to the top of the tube, positive control reagent containing inactivated H.pylori, and the package insert and instructions. Each diagnostic strip is enclosed in a plastic frame with a window to display the results. To perform the test, a diluted stool sample which is first prepared by a sample preparation tube is added to the Test Cassette. If the sample contains H.pylori antigen, a pink-red test to the letter T) along with a blue control line (next to the letter C) will be visible in the rectangle "Result Window", as depicted in Figure 1. A blue control line is a line to show that adequate flow of the sample has occurred and active components have been employed during a test run. The presence of the blue line at the control position on the device confirms that the device is working properly. If H. pylori antigen is absent or below the level of detection, no pink-red line will appear in the rectangle "Result Window" of the cassette next to the letter T, but a distinct blue line shows next to the letter C, as depicted in Figure 1. For invalid result, no visible blue line in the rectangle "Result Window" of the cassette next to the letter C, with or without a visually detectable pink-red line, as depicted in Figure 1. It may occur with the deteriorated materials, but an excess of stool sample and incorrect procedure is mostly the main reason for control line failure. When an invalid result appears, review the test procedure and re- test same specimen. If the test fails again, repeat the test with different specimens. If the problem persists, the use of concerned test kit lot should be discontinued.

AI/ML Overview

Here's a breakdown of the acceptance criteria and the study proving the device meets them, based on the provided text:

Device: Vstrip® H.pylori Antigen Rapid Test
Indication for Use: Single use immunochromatographic assay for the qualitative detection of H. pylori antigen in unpreserved human stool specimens. Test results are intended to aid in the initial diagnosis and treatment of H. pylori infection.

1. Table of Acceptance Criteria and Reported Device Performance

The core performance evaluation for the device relies on a "Comparison Study" against an FDA-cleared H. pylori stool antigen ELISA. The acceptance criteria for this study are specified in the last paragraph of the "Comparison Study" section: "The study acceptance criteria were met." While the specific numerical targets for the acceptance criteria aren't explicitly stated in a standalone table, they are implied by the performance of the comparator ELISA, which was previously evaluated with "a demonstrated sensitivity and specificity greater than or equal to 95% and a lower bound of the two-sided 95% confidence interval (CI) greater than 89%." The Vstrip device's performance is then reported against these implied criteria.

Acceptance Criteria (Implied by Comparator ELISA Performance)	Reported Device Performance (Vstrip® H.pylori Antigen Rapid Test)
Positive Percent Agreement (PPA) with comparator ELISA: ≥ 95% (with 95% CI lower bound > 89%)	96.67% [58/60; 95% CI 88.64% - 99.08%]
Negative Percent Agreement (NPA) with comparator ELISA: ≥ 95% (with 95% CI lower bound > 89%)	98.17% [268/273; 95% CI 95.79% - 99.22%]

Other performance studies with implied acceptance criteria:

Study Category	Implied Acceptance Criteria	Reported Device Performance
Reproducibility	High agreement with expected results across operators and sites.	Across all sites and operators, agreement with the expected result was: - Moderate positive: 97.8% (88/90) - Low positive: 97.8% (88/90) - High negative: 98.9% (89/90) - True negative: 100% (90/90)
Analytical Sensitivity (LOD)	A defined Limit of Detection (LOD) for the strains tested.	LOD for ATCC 43504: 8.5 x 10^5 CFU/mL LOD for ATCC 51653: 1.9 x 10^5 CFU/mL
Inclusivity	Positive results for additional H. pylori strains.	ATCC700392: 3.8 x 10^5 CFU/mL (positive at least 95% of the time) ATCC 51110: 1.9 x 10^5 CFU/mL (positive at least 95% of the time) BCRC 17132: 3.8 x 10^6 CFU/mL (positive at least 95% of the time)
Analytical Specificity (Cross-reactivity)	No false positive or false negative results with non-target microorganisms.	None of the microorganisms tested produced false positive or false negative results. (Tested 37 bacteria, 7 virus types)
Interfering Substances	No interference with assay results from common medications or endogenous substances.	None of the substances with the indicated concentrations interfered with the performance. (Tested 15 potentially interfering substances)
Sample Stability	Established stability parameters for storage and freeze/thaw cycles.	Stool samples can be stored: - Up to 7 days refrigerated at 2-8°C - Up to 20 days frozen at -20°C Samples can undergo up to three freeze/thaw cycles.
Dose-Hook Effect (Prozone)	No negative affects on performance at high antigen concentrations.	No dose hook effect was observed at the tested concentrations (10^5 - 10^8 CFU/mL, 10-100X LoD for 5 H. pylori strains).

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

Sample Size for Comparison Study (Test Set): A total of 333 fresh fecal specimens.
- Provenanc_e: 150 fresh fecal samples collected in the USA and 183 fresh fecal samples collected in Taiwan. The study was prospective as samples were collected for the study from the intended use population.
Sample Size for Reproducibility Study: 5 panels of 12 frozen fecal samples each, analyzed over 5 days by multiple operators at multiple laboratories. This means 5 panels * 12 samples/panel * 5 days = 300 samples per operator for the agreement calculation, and 90 replicates per panel member (5 panels * 18 replicates/panel, with 3 sites * 2 operators * 3 replicates). The specific breakdown for 90 replicates is 3 sites * 2 operators * 5 days * 3 replicates, suggesting a total of 90 replicates per panel member.
Sample Size for Analytical Sensitivity (LOD): Each dilution was tested 10 times by four operators (a total of 40 replicates).
Sample Size for Inclusivity: Not explicitly stated, but implies sufficient testing to achieve 95% positive results.
Sample Size for Analytical Specificity: Each condition was run in triplicate. (37 bacteria and 7 virus types).
Sample Size for Interfering Substances: Both positive and negative samples tested in triplicate for each of the 15 substances.
Sample Size for Dose-Hook Effect Study: Five H. pylori strains were tested in triplicate at various concentrations.

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

The ground truth for the comparison study was established by an FDA cleared H. pylori stool antigen ELISA that had been previously evaluated relative to an endoscopy biopsy composite reference method. Therefore, no human experts were involved in establishing the ground truth for this device's test set directly. The ground truth for the comparator ELISA itself was established via a composite reference method (culture, histology, and RUT), which would typically involve expert interpretation (e.g., pathologists for histology, microbiologists for culture/RUT), but the focus of this 510(k) is the Vstrip device's performance against the cleared ELISA, not the ELISA's performance against the composite reference.

4. Adjudication Method for the Test Set

Since the ground truth for the comparison study was established by a single, previously validated ELISA, there was no adjudication method described for the Vstrip device's test set. The Vstrip results were simply compared to the ELISA results.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done, and the effect size of how much human readers improve with AI vs without AI assistance

No MRMC comparative effectiveness study was done. This device is a rapid diagnostic test (qualitative immunoassay) and is not intended to be "read" by human readers in the same way an imaging AI study is. The result (presence/absence of line) is a direct output of the device, not an interpretation of a complex image. Therefore, there's no concept of human readers improving with AI assistance in this context.

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

This device is essentially a standalone test in its performance evaluation. The "reading" of the test (presence of lines) is visual and straightforward, not involving a complex "human-in-the-loop" interpretation process like an imaging algorithm. The "reported device performance" directly reflects the algorithm's (immunoassay's) output. The comparison study evaluates the device's agreement with a reference method, which is a standalone performance assessment.

7. The Type of Ground Truth Used

The primary ground truth for the device's performance evaluation was an FDA cleared H. pylori stool antigen ELISA. This ELISA, in turn, had its ground truth established previously by a composite reference method (culture, histology, and RUT). So, indirectly, the ground truth traces back to a combination of laboratory and pathology results.

8. The Sample Size for the Training Set

The provided text does not mention a training set or machine learning model. The Vstrip H.pylori Antigen Rapid Test is an immunochromatographic assay, a biochemistry-based diagnostic test, not an AI or machine learning algorithm. Therefore, the concept of a "training set" in the context of machine learning doesn't apply. The development of such a device involves biochemical optimization rather than data-driven model training.

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

As there is no training set for this type of device (immunoassay), this question is not applicable. The development of the device likely involved extensive research and development to select appropriate antibodies and optimize the assay chemistry to achieve specificity and sensitivity to H. pylori antigens.

Summary

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Image /page/0/Picture/0 description: The image shows the logo of the U.S. Food and Drug Administration (FDA). On the left is the Department of Health & Human Services logo. To the right of that is the FDA logo in blue. Underneath the FDA logo is the word "ADMINISTRATION".

March 14, 2019

Panion & BF Biotech Inc. % Kazem Kazempour CEO & President Amarex Clinical Research, LLC 20201 Century Blvd. Fourth Floor Germantown, Maryland 20874

Re: K183573

Trade/Device Name: Vstrip H. pylori Antigen Rapid Test Regulation Number: 21 CFR 866.3110 Regulation Name: Campylobacter fetus serological reagents Regulatory Class: Class I Product Code: LYR Dated: December 19, 2018 Received: December 21, 2018

Dear Kazem Kazempour:

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. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database located at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. 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 Part

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801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/CombinationProducts/GuidanceRegulatoryInformation/ucm597488.htm); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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 comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/) and CDRH Learn (http://www.fda.gov/Training/CDRHLearn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (http://www.fda.gov/DICE) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).

Sincerely,

Steven R. Gitterman -S 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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Indications for Use

510(k) Number (if known)

K183573

Device Name

Vstrip® H.pylori Antigen Rapid Test

Indications for Use (Describe)

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

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1.	Date of Preparation: March 13, 2019	2
2.	Owner Information	2
3.	Device	2
4.	Device Description	2
5.	Principle of the Test and Assay Procedures	3
6.	Rationale of Antibody Selection and Information of Selective H pylori Strains	4
7.	Intended Use	4
8.	Indications of Use	4
9.	Comparison of Vstrip® H.pylori Antigen Rapid Test with the Predicate Device	4
10.	Performance Data	6
11.	Conclusions	7

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510(K) SUMMARY

Date of Preparation: March 13, 2019 1.

2. Owner Information

This Premarket Notification is submitted by:

Panion & BF Biotech Inc. 1F, No.308-8, Sec. 1 Datong Rd., Xizhi Dist. New Taipei City 22146, Taiwan

Contact Information:

Kazem Kazempour, CEO Amarex Clinical Research, LLC 20201 Century Blvd, Fourth Floor Germantown, MD 20874 Phone: 240-688-0800 Fax: 301-528-2300 Email: kazemk@amarexcro.com

3. Device

Name of Device:	Vstrip® H. pylori Antigen Rapid Test
Common Name:	Helicobacter pylori antigen assay
Classification Name:	Campylobacter fetus serological reagents (21 CFR 866.3110)
Regulatory Class:	Class I
Product Code:	LYR
Predicate Device:	ImmunoCard STAT!® HpSA® [K032222]

Device Description 4.

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stool samples, and test results are intended to aid in the diagnosis and treatment of H. pylori infection. This test utilizes a pair of H. pylori-specific monoclonal antibodies that are capable of detecting H.pylori antigens in human stool. The assay kit includes a foil pouch containing test cassette which houses a strip incorporated with a pair of H. pylori-specific monoclonal antibodies, sample preparation tubes that contain sample diluent buffer for dilution of stool sampler tool attached to the underside of the tube cap and a dispenser tool attached to the top of the tube, positive control reagent containing inactivated H.pylori, and the package insert and instructions. Each diagnostic strip is enclosed in a plastic frame with a window to display the results. To perform the test, a diluted stool sample which is first prepared by a sample preparation tube is added to the Test Cassette. If the sample contains H.pylori antigen, a pink-red test to the letter T) along with a blue control line (next to the letter C) will be visible in the rectangle "Result Window", as depicted in Figure 1. A blue control line is a line to show that adequate flow of the sample has occurred and active components have been employed during a test run. The presence of the blue line at the control position on the device confirms that the device is working properly. If H. pylori antigen is absent or below the level of detection, no pink-red line will appear in the rectangle "Result Window" of the cassette next to the letter T, but a distinct blue line shows next to the letter C, as depicted in Figure 1. For invalid result, no visible blue line in the rectangle "Result Window" of the cassette next to the letter C, with or without a visually detectable pink-red line, as depicted in Figure 1. It may occur with the deteriorated materials, but an excess of stool sample and incorrect procedure is mostly the main reason for control line failure. When an invalid result appears, review the test procedure and re- test same specimen. If the test fails again, repeat the test with different specimens. If the problem persists, the use of concerned test kit lot should be discontinued.

Figure 1: Schematic Diagram of Device with all possible outcomes

Image /page/5/Figure/4 description: The image shows four different H. pylori Ag tests. The first test is positive, as indicated by the presence of two lines, one at the control (C) and one at the test (T) position. The second test is negative, as indicated by the presence of only one line at the control (C) position. The third and fourth tests are invalid, as indicated by the presence of only one line at the test (T) position or no lines at all.

Principle of the Test and Assay Procedures 5.

Vstrip® H.pylori Antigen Rapid immunochromatographic assay that utilizes a pair of

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H. pylori-specific monoclonal antibodies to detect the presence of fecal H. pylori antigens indicated by a pink-red color line.

To perform the test, a diluted stool sample which is first prepared by a sample preparation tube is added to the Test Cassette and read the result at 10 minutes. All stool specimens and assay procedures must be handled at room temperature and on a flat surface.

Rationale of Antibody Selection and Information of Selective H. pylori Strains 6.

In literature, the flagella part of H.pylori has been studied extensively and demonstrated the key role of their colonization in bacteria, inflammation, and immune evasion. Filament, a copolymer of the flagellin subunits, is an important subunit of H.pylori flagella and plays an important role in motility. As motility is essential for H. pylori colonization in the human gastric mucosa, anti- H.pylori monoclonal antibody (Ab) against flagellin was utilized to develop Vstrip® H.pylori Antigen Rapid Test.

7. Intended Use

Indications of Use 8.

Same as Intended Use

Comparison of Vstrip® H.pylori Antigen Rapid Test with the Predicate Device 9.

The comparison of assay methods between Vstrip® H. pylori Antigen Rapid Test and ImmunoCard STAT! " HpSA" is shown in Table 1. Panion & BF Biotech Inc. (PBF) believes that Vstrip® H.pylori Antigen Rapid Test employs the same technological characteristics for the same intended use as the predicate.

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Characteristic	Device: Vstrip® H. pylori AntigenRapid Test	Predicate: ImmunoCard STAT!® HpSA®K032222
IntendedUse/Indication forUse	Vstrip® H.pylori Antigen Rapid Test is asingle use immunochromatographicassay for the qualitative detection of H.pylori antigen in unpreserved humanstool specimens. Test results areintended to aid in the initial diagnosisand treatment of H. pylori infection. Testresults should be taken into considerationby the physician in conjunction with thepatient history and symptoms.	The ImmunoCard STAT! HpSA is a rapid invitro qualitative procedure for the detection of Hpylori antigens in human stool. The stool antigendetection is intended to aid in the diagnosis of H.pylori infection and to demonstrate loss ofH.pylori stool antigen following treatment.Conventional medical practice recommends thattesting by any method to confirm loss of antigenbe done at least four weeks following completionof therapy.
Product Code	LYR	Same
Test Type	Qualitative	Same
Specimen Required	Formed stool, semi-solid stool,	Same
Technology	Lateral flow chromatography	Same
Capture Antibody	Monoclonal anti-H. pylori	Same
Conjugate	Red-latex conjugated anti-H. pylori	Same
Assay Steps	Dilute specimen in provided sample diluents Add diluted specimen to test port Incubate for room temperature for 10 minutes Read results visually	Dilute specimen in provided sample diluents Add diluted specimen to test port Incubate for room temperature for 5 minutes Read results visually
End point	Visual color bands	Same
Interpretation oftest results	NEGATIVE = Only Blue band at controlline close to letter "C".POSITIVE = Blue line at control lineplus Pink-red band at the test line closeto letter "T".	Same
Differences
Level of skillrequired	Laboratory setting	Untrained Users
Kit Storagetemperature	15-30 °C	2-8 °C
Time to read	10 min	5 min

Table 1: Comparison with Predicate

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10. Performance Data

Comparison Study

A multi-center study including sites from USA and Taiwan was conducted to evaluate the performance of the study test device (Vstrip® H.pylori Antigen Rapid Test) for detecting H. pylori stool antigen (HpSA) in human stool from patients suspected of H. pylori infection. Test results were compared to results from an FDA cleared H. pylori stool antigen ELISA that was previously evaluated relative to the endoscopy biopsy composite reference method (i.e., culture, histology, and RUT) for initial H. pylori diagnosis with a demonstrated sensitivity and specificity greater than or equal to 95% and a lower bound of the two-sided 95% confidence interval (CI) greater than 89%.

A total of 333 fresh fecal specimens from the intended use population (150 fresh fecal samples collected in the USA and 183 fresh fecal samples collected in Taiwan) along with test device and comparator kits were provided by the Sponsor to the selected study laboratories. Trained laboratory operators were recruited for this study and were blinded to the samples designations.

Positive, negative and overall percent agreement were determined between Vstrip® H.pylori Antigen Rapid Test and the comparator ELISA in detecting the H. pylori antigen in human stool. No invalid results were observed for the investigational test or the comparator ELISA. The Vstrip H.pylori Antigen Rapid Test demonstrated a positive percent of 96.67% [58/60; 95% CI 88.64% - 99.08%] and a negative percent agreement of 98.17% [268/273; 95% CI 95.79% -99.22%] with the comparator ELISA. The study acceptance criteria were met.

Reproducibility Study

A study was conducted to evaluate the reproducibility of Vstrip® H.pylori Antigen Rapid Test results in detecting H.pylori antigen in human stool, as performed by different operators in multiple laboratories.

Five (5) panels of 12 frozen fecal samples each with random distributions of medium positive (4xLOD), low positive (1-2xLOD, near C95 concentration), high negative (near C5 concentration) and negative samples) were analyzed using the Vstrip® H.pylori Antigen Rapid Test by each operator at each site over five (5) days (one (1) panel per day per operator).

Across all sites and operators, agreement with the expected result was 97.8% (88/90) for the moderate positive panel member, 97.8% (88/90) for the low positive panel member, 98.9% (89/90) for the high negative panel member, and 100% (90/90) for the true negative panel member. The reproducibility study analyses demonstrated that results of the Vstrip® H.pylori Antigen Rapid Test are reproducible by different operators in multiple locations.

Analytical Sensitivity

A study was done to establish the limit of detection (LOD) for the Vstrip® H.pylori Antigen Rapid test. The LOD testing was conducted in a stool matrix background comprised from three negative stool samples spiked with serial dilutions of two strains of cultured H. pylori (ATCC 43504 and ATCC 51653). Each dilution was tested with the Vstrip® H.pylori Antigen Rapid test 10 times each by four operators (a total of 40 replicates). The LOD value for Vstrip® H.pylori Antigen Rapid Test was defined as the concentration producing a positive result at least 95% of the time. The LOD value for Vstrip® H.pylori Antigen Rapid Test based on 95% positive results was 8.5X10 CFU/mL

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for H.pylori strain ATCC 43504 and 1.9 X10 CFU/mL for H.pvlori strain ATCC 51653.

Inclusivity

An additional three H. pylori strains produced a positive result at least 95% of the time with the Vstrip H.pylori Antigen Rapid Test when tested at the following concentrations: ATCC700392 (3.8 x 10 CFU/mL), ATCC 51110 (1.9 x 105 CFU/mL), and BCRC 17132 (3.8 x 106 CFU/mL).

Analytical Specificity

A study was done to determine analytical specificity (cross reactivity) of the Vstrip® H.pylori Antigen Rapid Test with panels of viruses and bacteria. The test was performed on positive and negative samples containing high levels of non-target microorganisms (bacteria spiked at ≥1x10' CFU/mL, viruses spiked at ≥1x10 TCID50/mL). Testing included thirty seven (37) bacteria and seven (7) virus types. Various strains of viruses and bacteria panels were diluted and tested with the Vstrip® H.pylori Antigen Rapid Test to detect any potential cross-reactivity. Results were recorded at 10 minutes interval. Each condition was run in triplicate. None of the microorganisms tested produced false positive or false negative results.

Interfering Substances

A study was conducted to determine if various over-the-counter medications or endogenous substances could interfere with the assay results. Fifteen potentially interfering substances were spiked in both positive and negative samples tested in triplicate with the Vstrip® H.pylori Antigen Rapid Test. None of substances with the indicated concentrations interfered with the performance of Vstrip® H.pylori Antigen Rapid Test.

Sample Stability

Studies were conducted to examine the stability of stool samples when stored refrigerated at 2-8° C or frozen at -20° C. The study results supported the recommendations that stool samples can be stored up to seven days refrigerated at 2-8° C, up to 20 days frozen at -20° C, and that samples can undergo up to three freeze/thaw cycles.

Dose-Hook Effect Study

A dose hook effect (prozone) study was carried out to examine whether high concentrations of H. pylori antigen negatively affects the performance of the Vstrip®. The hook effect or the prozone effect is a type of interference which produces false negatives or inaccurately low results in the presence of high analyte concentrations. Five H pylori strains were tested in triplicate at 10° 10′ CFU/mL (10 - 100X LoD) concentration range with the Vstrip® H.pylori Antigen Rapid Test. No dose hook effect was observed at the tested concentrations.

11. Conclusions

The conclusions drawn from the nonclinical and clinical studies demonstrate that the Vstrip® H.pylori Antigen Rapid Test is safe and effective and substantially equivalent to the predicate device in performance.

Regulation Number and Section

§ 866.3110

Campylobacter fetus serological reagents.(a)
Identification. Campylobacter fetus serological reagents are devices that consist of antisera conjugated with a fluorescent dye used to identifyCampylobacter fetus from clinical specimens or cultured isolates derived from clinical specimens. The identification aids in the diagnosis of diseases caused by this bacterium and provides epidemiological information on these diseases.Campylobacter fetus is a frequent cause of abortion in sheep and cattle and is sometimes responsible for endocarditis (inflammation of certain membranes of the heart) and enteritis (inflammation of the intestines) in humans.(b)
Classification. Class I (general controls).