GENZYME OSOM TRICHOMONAS RAPID TEST

K033864 · Genzyme Corp. · JWZ · Apr 2, 2004 · Microbiology

Device Facts

• Record ID: K033864
• Device Name: GENZYME OSOM TRICHOMONAS RAPID TEST
• Applicant: Genzyme Corp.
• Product Code: JWZ · Microbiology
• Decision Date: Apr 2, 2004
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 866.2660
• Device Class: Class 1

Indications for Use

The OSOM® Trichomonas Rapid Test is intended for the qualitative detection of Trichomonas vaginalis (Trichomonas) antigens from vaginal swabs or from the saline solution prepared when making wet mounts from vaginal swabs. This test is intended for use in patients with symptoms of vaginosis/vaginitis or suspected exposure to the Trichomonas pathogen.

Device Story

OSOM Trichomonas Rapid Test is a lateral flow immunochromatographic dipstick assay for qualitative detection of Trichomonas vaginalis antigens. Input: vaginal swab or saline solution from wet mount preparation. Principle: solubilized Trichomonas proteins migrate along a nitrocellulose membrane; target antigens bind to blue-colored particle-conjugated primary antibodies; complex captured by secondary antibody on membrane. Output: visual blue test line (positive) and red control line. Used in physician offices and clinical labs by healthcare professionals. Provides rapid point-of-care diagnostic information to assist in clinical management of patients presenting with vaginosis/vaginitis symptoms.

Clinical Evidence

Clinical study of 449 patients comparing OSOM test to wet mount microscopy and InPouch™ culture. Vaginal swab sensitivity 83% (76-91% CI), specificity 99% (98-100% CI). Saline wet mount sample sensitivity 75% (67-84% CI), specificity 99% (97-100% CI). Agreement with composite reference standard was 95%.

Technological Characteristics

Lateral-flow immunochromatographic dipstick. Materials: membrane, mouse monoclonal antibodies, blue latex conjugate particles. Qualitative visual readout. Standalone point-of-care device. No external energy source or software required.

Indications for Use

Indicated for qualitative detection of Trichomonas vaginalis antigens in patients with symptoms of vaginosis/vaginitis or suspected exposure to the pathogen. Suitable for use in physicians' offices and clinical laboratories.

Regulatory Classification

Identification

A microorganism differentiation and identification device is a device intended for medical purposes that consists of one or more components, such as differential culture media, biochemical reagents, and paper discs or paper strips impregnated with test reagents, that are usually contained in individual compartments and used to differentiate and identify selected microorganisms. The device aids in the diagnosis of disease.

Predicate Devices

• Xenotope XenoStrip®-Tv Test (K020226)

Reference Devices

• InPouch™ TV culture

Submission Summary (Full Text)

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510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION
DECISION SUMMARY
DEVICE ONLY TEMPLATE

A. 510(k) Number:
K033864

B. Analyte:
Trichomonas vaginalis antigens

C. Type of Test:
Chromatographic, lateral flow immunoassay, qualitative

D. Applicant:
Genzyme General Diagnostic.

E. Proprietary and Established Names:
OSOM® Trichomonas Rapid Test

F. Regulatory Information:
1. Regulation section:
21 CFR Part 866.2660 Microorganism Differentiation and Identification
Limitation: 21 CFR 866.9 (6)
2. Classification:
Class I
3. Product Code:
JWZ – Trichomonas screening
4. Panel:
83 (Microbiology)

G. Intended Use:
5. Intended use(s):
The OSOM® Trichomonas Rapid Test is intended for the qualitative detection of Trichomonas vaginalis (Trichomonas) antigens from vaginal swabs or from the saline solution prepared when making wet mounts from vaginal swabs. This test is intended for use in patients with symptoms of vaginosis/vaginitis or suspected exposure to the Trichomonas pathogen.
6. Indication(s) for use:

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This test is intended for use in patients with symptoms of vaginosis/vaginitis or suspected exposure to the Trichomonas pathogen. This device is intended for use in physicians' offices as well as clinical laboratories.

7. Special condition for use statement(s):

Prescription Use.

8. Special instrument Requirements:

Not applicable

# H. Device Description:

The OSOM® Trichomonas Rapid Test kit is a color, immunochromatographic, lateral-flow "dipstick" assay. The test procedure requires the dissolving of Trichomonas proteins from a vaginal swab by mixing the swab in sample buffer. The device test stick is placed in the sample mixture and the mixture migrates along the membrane surface by capillary action. If Trichomonas is present in the sample, it will form a complex with the primary anti-Trichomonas antibody conjugated to colored (blue) particles. The complex is then bound by a second anti-Trichomonas capture antibody at the end of the membrane. The appearance of a visible blue test line together with the red control line indicates a positive result.

# I. Substantial Equivalence Information:

1. Predicate device name(s):

Xenotope XenoStrip® -Tv Test

2. Predicate K number(s):

K 020226

3. Comparison with predicate:

| Similarities | | |
| --- | --- | --- |
| Item | Device | Predicate |
| Intended Use | The OSOM® Trichomonas Rapid Test is intended for the qualitative detection of Trichomonas vaginalis (“Trichomonas”) antigens from vaginal swabs or from the saline solution prepared when making wet mounts from vaginal swabs. This test is intended for use in patients with symptoms of vaginosis/vaginitis or suspected exposure to the Trichomonas pathogen. | The Xenotope Diagnostics’ Inc. XenoStrip™ -Tv Trichomonas Test is intended for the qualitative detection of Trichomonas vaginalis (“Trichomonas”) antigens from vaginal swabs. This test is intended for use in patients with symptoms of vaginosis/vaginitis or suspected or suspected exposure to the pathogen. |
| Technology | Lateral flow | Lateral flow |
| Antibodies (labeled | Mouse monoclonal | Mouse monoclonal |

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| and capture) | antibodies | antibodies |
| --- | --- | --- |
| Specimen type | vaginal swabs
saline solution prepared for
wet mount microscopy | vaginal swabs |
| Indication for Use | Professional Use | Professional Use |
| Internal control | Yes-red line | Yes-red line |
| Differences | | |
| Item | Device | Predicate |
| conjugate | latex | Colloidal gold |
| Analytical sensitivity | 2500 organisms/ml | 1-10 organisms/swab |
| Clinical sensitivity | Vaginal swab 83%
Saline from wet mount 75% | 100% |
| Clinical specificity | 99 % | 98.1% |

## J. Standard/Guidance Document Referenced (if applicable):

Not applicable

## K. Test Principle:

The OSOM® Trichomonas Rapid Test uses color immunochromatographic, capillary flow, “dipstick” technology. The test procedure requires the dissolution of Trichomonas proteins from a vaginal swab by mixing it in a sample buffer.

The dipstick is then placed in the sample mixture and the mixture migrates along the membrane surface. If Trichomonas is present in the sample, it will form a complex with the primary anti-Trichomonas antibody conjugated to colored (blue) particles. The complex is subsequently bound by the second anti-Trichomonas capture antibody. The appearance of a visible blue test line together with the red control line indicates a positive result.

## L. Performance Characteristics (if/when applicable):

### 1. Analytical performance:

a. Precision/Reproducibility:
Reproducibility testing was conducted by two operators, on three lots, for 5 separate days with blinded samples of varying activity. A total of 540 samples were tested with no discordant results.

b. Linearity/assay reportable range:
Not applicable

c. Traceability (controls, calibrators, or method):
Not applicable

d. Detection limit:
The OSOM® Trichomonas Rapid Test consistently detected antigen derived from 2500 organisms per ml.

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e. Analytical specificity:

Cross-reactivity:
Cross-reactivity studies were performed using the OSOM® Trichomonas Rapid Test. The following organisms were tested at least 1 x 10⁸ organisms/ml. T. foetus, C. trachomatis, and C. albicans samples tested at approximately 0.5 x 10⁵ organisms per ml.

| Bacteriodes merdae | Lactobacillus acidophilus | Salmonella typhimurium |
| --- | --- | --- |
| Candida albicans | Mobuluncus curtesii | Shigella flexneri |
| Chlamydia trachomatis | Tritrichomonas foetus | Streptococcus agalactiae |
| Escherichia coli | Monella choleraesuis | Staphylococcus aureus |
| Gardnerella vaginalis | Neisseria gonorrhoeae | Streptococci Group B |

Interfering Substances:
Other interfering substance testing was also performed.

| Condoms, with spermicide | TYM Culture Medium |
| --- | --- |
| HeLa cells | HVEC cells |
| Douche (vinegar) | Human blood |

Vaginal yeast treatment (Monistat® brand)

The testing demonstrated that the potentially interfering substances do not cross react with the OSOM® Trichomonas Rapid Test with the exception of high concentrations of Staphylococcus aureus at concentrations > 1 x 10⁸. In addition, douche medicated with iodine diluted 1:2 and K-Y Jelly diluted 1:4 also showed some degree of cross reactivity.

f. Assay cut-off:
The assay detection limit is 2500 organisms per ml. Clinically relevant detection limits were determined using laboratory cultured samples of Trichomonas vaginalis. T. vaginalis was adjusted to stock concentrations of 1.33 x 10⁴ and 1.0 x 10⁴ organisms per ml. Two fold serial dilutions were performed on each stock. The lowest concentration tested was 8.33 x 10² organisms per ml.

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2. Comparison studies:
a. Method comparison with predicate device:
Not applicable
b. Matrix comparison:
Not applicable

3. Clinical studies:
a. Clinical sensitivity:
Sensitivity and Specificity Compared to Wet mount, and Culture:

A total of 449 patients, 448 of the wet mount saline samples and 439 swabs were received for testing with the device. 445 samples for culture utilizing the InPouch™ testing were read. Patients were selected based on presentation of symptoms of vaginosis/vaginitis or suspected exposure to Trichomonas infection. Three swabs were collected from each patient. One swab was randomly selected from the three and evaluated by standard wet mount microscopy. The wet mount was conducted at the investigational site. Another swab, selected randomly, was used for direct inoculation of a BioMed In-Pouch™ culture performed at the clinical site. The remaining swab was frozen for shipment to Genzyme for testing on the OSOM device. The swab and solution remaining from the wet mount microscopy was frozen and sent to Genzyme for testing with the OSOM device.

The results are summarized as follows:

**Sensitivity, and Specificity**

Table 1
COMPARISON OF OSOM® TRICHOMONAS RAPID TEST TO
WET MOUNT MICROSCOPY

| | Wet Mount Microscopy | | Total | |
| --- | --- | --- | --- | --- |
| | | + | | - |
| OSOM® Trichomonas Rapid Test (vaginal swab) | + | 69 | 20* | 89 |
| | - | 3 | 345 | 348 |
| Total | | 72 | 365 | 437 |

*Of the 20 samples negative by wet mount, 16 were positive by culture and 4 were negative.

Sensitivity: 69/ 72 = 96% (91-100%)

Specificity: 345/ 365 = 95% (92-97%)

Agreement: 414/ 437 = 95% (93-97%)

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*(Confidence intervals in parenthesis)*

Table 2
COMPARISON OF OSOM® TRICHOMONAS RAPID TEST
TO COMPOSITE REFERENCE STANDARD

| | | Composite Reference Standard | | Total |
| --- | --- | --- | --- | --- |
| | | + | - | |
| OSOM® Trichomonas Rapid Test (vaginal swab) | + | 85 | 4 | 89 |
| | - | 17 | 331 | 348 |
| Total | | 102 | 335 | 437 |
| Sensitivity: | 85/ | 102 | = 83% (76-91%) | |
| Specificity: | 331/ | 335 | = 99% (98-100%) | |
| Agreement: | 416/ | 437 | = 95% (93-97%) | |

Table 3
COMPARISON OF OSOM® TRICHOMONAS RAPID TEST
SALINE FROM WET MOUNT SAMPLE
TO COMPOSITE REFERENCE STANDARD

| | | Composite Reference Standard | | Total |
| --- | --- | --- | --- | --- |
| | | + | - | |
| OSOM® Trichomonas Rapid Test (saline from wet mount) | + | 79 | 5 | 84 |
| | - | 26 | 337 | 363 |
| Total | | 105 | 342 | 447 |
| Sensitivity: | 79/ | 105 | = 75% (67-84%) | |
| Specificity: | 337/ | 342 | = 99% (97-100%) | |
| Agreement: | 416/ | 447 | = 93% (91-95%) | |

Table 4
SENSITIVITY OF EACH METHOD
VERSUS COMPOSITE REFERENCE STANDARD

| Method | Sensitivity |
| --- | --- |
| OSOM® Trichomonas Rapid Test (vaginal swab) | 83% |
| OSOM® Trichomonas Rapid Test (saline from wet mount) | 75% |
| Wet Mount Microscopy | 71% |
| Culture (InPouch™ TV) | 99% |

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b. Clinical specificity:
Refer to (a) above

c. Other clinical supportive data (when a and b are not applicable):
Not applicable

4. Clinical cut-off:
See assay cut off above

5. Expected values/Reference range:
Studies have shown that the incidence of Trichomonas infections by culture in women presenting to STD clinics is between 8-37%. In a clinical trial involving the OSOM Trichomonas Test at eight sites, including STD clinics, hospital emergency departments, and public health clinics, the incidence of Trichomonas infections detected by culture or wet mount ranged from 13% to 29%. Up to 50% of women infected with Trichomonas may not be aware of symptomology. The highest incidence of this disease is found in women with at-risk factors that predispose them to acquiring sexually transmitted diseases. Trichomoniasis also has a high likelihood of co-infection with other STDs, including those that also result in symptoms of vaginitis.

M. Conclusion:
In clinical settings, the OSOM® Trichomonas Rapid Test is substantially equivalent in performance to the predicate device and to culture examination for the identification of Trichomonas vaginalis in vaginal swabs and saline solution prepared when making wet mounts from vaginal swab specimens.