The E. histolytica II is an enzyme immunoassay for the rapid detection of the adhesin of E. histolytica in human fecal specimens. It is indicated for use with fecal specimens from patients with diarrhea or dysentery to determine the presence of E. histolytica gastrointestinal infection. The test can be used for fecal specimens submitted for routine clinical testing from adults or children. Conventional microscopy is not a routine prerequisite for use of the test. FOR IN VITRO DIAGNOSTIC USE.

Device Description

The E. histolytica II can be used to detect adhesin (also referred to as galactose-inhibitable lectin) produced by strains of E. histolytica. It does not cross-react with the adhesin from E. dispar (formerly known as nonpathogenic E. histolytica). The test can be used to detect the adhesin in fecal specimens from persons suspected of having amebiasis. The kit, which includes ready-to-use reagents, contains microtiter wells coated with polyclonal antibody, positive control reagent, monoclonal-antibody conjugate, diluent, one component substrate, wash solution, and stop solution. The microtiter wells coated with polyclonal antibody "capture" the adhesin and the monoclonal antibody conjugate serves as the "detecting" antibody. The polyclonal antibody used to coat the wells is prepared from hyperimmune antiserum developed in goats. The monoclonal antibody used to prepare the conjugate is prepared from mouse ascites fluid. The E. histolytica II is to be used in an ELISA format.

AI/ML Overview

Here's an analysis of the acceptance criteria and the study proving the device's performance, based on the provided text:

Device Name: E. histolytica II

1. Table of Acceptance Criteria and Reported Device Performance:

The document explicitly states that "No performance standards have been developed for this device under §514 of the Food, Drug, and Cosmetic Act." Therefore, formal acceptance criteria in terms of specific sensitivity, specificity, or accuracy thresholds are not listed. Instead, the study's goal was to demonstrate substantial equivalence and improved sensitivity compared to a predicate device and a "gold standard."

The reported performance focuses on correlation with the gold standard and improved sensitivity compared to a previous test.

Acceptance Criteria (Implied)	Reported Device Performance
> Substantial equivalence to culturing and zymodeme analysis	> "substantially equivalent to culturing and zymodeme analysis"
> More sensitive than predicate device (E. histolytica TEST)	> "more sensitive than our E. histolytica TEST"
> High specificity for pathogenic E. histolytica	> "highly specific for pathogenic Entamoeba"
> Correlation with zymodeme analysis	> "correlation of >97% when compared with zymodeme analysis"

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

Sample Size for Test Set: The exact number of stool specimens analyzed in the clinical evaluations is not specified in the provided text. It only states that the E. histolytica II was used to analyze "stool specimens in areas where amebiasis is endemic."
Data Provenance:
- Country of Origin: Not explicitly stated, but the phrase "areas where amebiasis is endemic" suggests diverse geographical locations where the disease is prevalent.
- Retrospective or Prospective: Not explicitly stated. The description "the E. histolytica II was used to analyze stool specimens...and the results were compared with zymodeme analysis...and with the E. histolytica TEST" could imply either retrospective analysis of archived samples or prospective collection. Without further detail, it cannot be definitively determined.

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

Number of Experts: Not specified.
Qualifications of Experts: Not specified. The "zymodeme analysis" is described as being performed in "a select number of clinical laboratories around the world" that are "capable of performing this type of analysis." This implies highly specialized personnel, but specific qualifications are not detailed.

4. Adjudication Method for the Test Set:

The text does not describe an explicit adjudication method between multiple readers or experts for the test set. The ground truth ("gold standard") was established by "zymodeme analysis." The E. histolytica II results were then compared to this established ground truth, rather than adjudicated by experts confirming the E. histolytica II results.

5. If a Multi Reader Multi Case (MRMC) Comparative Effectiveness Study was done:

No, an MRMC comparative effectiveness study involving human readers and AI assistance was not performed. This device is an in-vitro diagnostic (IVD) ELISA kit, not an AI or imaging-based device that would typically involve human readers interpreting results with or without AI assistance. The comparisons are between different diagnostic tests (ELISA kit vs. culture/zymodeme vs. predicate ELISA kit).

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

Yes, in spirit, a standalone study was performed. The E. histolytica II kit itself is a standalone diagnostic tool. Its performance (detecting adhesin) was evaluated and compared directly against a "gold standard" (zymodeme analysis) and a predicate device (E. histolytica TEST) without human interpretation steps that would fundamentally alter the E. histolytica II's core measurement. The kit provides a direct result (e.g., color change indicating presence of adhesin).

7. The Type of Ground Truth Used:

Expert Consensus / Gold Standard: The ground truth used was zymodeme analysis. The document explicitly states, "For the purpose of our studies, zymodeme analysis represents the 'gold standard'." Zymodeme analysis determines if an isolated Entamoeba strain is pathogenic, which is the specific target of the E. histolytica II.

8. The Sample Size for the Training Set:

Not applicable / Not specified. As this is a traditional ELISA kit rather than a machine learning model, there isn't a "training set" in the conventional AI sense. The development of the antibodies and optimization of the assay would have involved various experimental samples, but these are not referred to as a "training set" in the context of AI.

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

Not applicable / Not specified. For an ELISA kit, the "ground truth" for developing the kit involves standard laboratory practices for antigen/antibody characterization, cross-reactivity testing, and determining optimal assay conditions. This would involve known positive and negative samples, purified antigens, and characterized strains, but it's not described as a "training set" with established ground truth in the same way as an AI model. The document mainly describes the components of the kit and its mechanism of action.

Summary

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12/21/99 K994101
SUMMARY OF SAFETY AND EFFECTIVENESS (E. histolytica II)
TE
E

1. Name of Manufacturer

TechLab. Inc. Corporate Research Center 1861 Pratt Drive, STE 1030 Blacksburg, VA 24060-6364

2. Establishment Registration

Federal ID # 54-1527427 Initial Registration of Medical Device Establishment, #1122855

3. Trade Name

E. histolytica II

4. Common Name

E. histolytica ELISA

5. Class of Device

This device is classified in Class II.

6. Performance Standards

No performance standards have been developed for this device under 514 of the Food, Drug, and Cosmetic Act.

7. Safety and Effectiveness

The E. histolytica II can be used to detect adhesin (also referred to as galactose-inhibitable lectin) produced by strains of E. histolytica. It does not cross-react with the adhesin from E. dispar (formerly known as nonpathogenic E. histolytica). The test can be used to detect the adlaesip in fest specimens from persons suspected of having amebiasis. The kit, which includes ready-to-use reagents, contains microtiter wells coated with polycloual antibody, positive control reagent, monclonal-antibody conjugate, diluent, one component substrate, wash solution, and stop solution, The microtiter wells coated with polyclonal antibody "capture" the adhesin and the monoclonal anthologyconjugate serves as the "detecting" antibody. The polyclonal antibody used to monthcound is prepared from hyperimmune antiserum developed in goats. The monoclonal antibody wedia prepare the conjugate is prepared from mouse ascites fluid

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SUMMARY OF SAFETY AND EFFECTIVENESS (E. histolytica II) (cont'd)

The E. histolytica II is to be used in an ELISA format and is substantially equivalent to culturing and zymodeme analysis that are used in some clinical laboratories as diagnostic aids. It also is more sensitive than our E. histolytica TEST (K955895), which has been cleared previously for in vitro diagnostic use. Culturing is used to obtain the isolate and zymodeme analysis is used to examine the enzyme profile of the isolate. Zymodeme analysis must be used to determine if the isolated Entamoeba strain is pathogenic. The major disadvantages are that culturing and zymodeme are timeconsuming and labor-intensive. Only a few clinical laboratories around the world are capable of performing this type of analysis. The E. histolytica II offers a major advantage to clinical laboratories because it is rapid, easy-to-perform, and it is more sensitive than our E. histolytica TEST, which was the first test to offer clinical labs a simpler and easier alternative format than zymodeme analysis for the specific detection of pathogenic E. histolytica. Like the E. histolytica TEST, the E. histolytica II is highly specific for pathogenic Entamoe a

The E. histolytica II is different from TechLab's Entumoeba TEST and the Alexon ProSpecT Entamoeba histolytica Test. These two tests detect both E. histolytica (formerly referred to as pathogenic E. histolytica) and E. dispar (formerly referred to as nonpathogenic E. histolytica). They do not distinguish between E. histolytica and E. dispar. The E. histolytica II is very similar to TechLab's E. histolytica TEST. Both are highly specific for the adhesin of E. histolytica and neither cross-reacts with the adhesin of E. dispar. Both have the same procedure and utilize an ELISA format. The difference between the E. histolytica II and the E. histolytica TEST is that the E. histolytica II offers increased sensitivity. Although all of these tests serve as diagnostic aids for amebiasis, the E. histolytica II is specific for pathogenic strains and offers higher sensitivity.

The E. histolytica II was used to analyze stool specimens in areas where amebiasis is endemic, and the results were compared with zymodeme analysis of Entamoeba isolates cultured from these specimens and with the E. histolytica TEST. It is important to remember that culture, without the aid of zymodeme analysis, does not distinguish between E. dispar. Zymodeme analysis, which is available only in a sclect number of clinical laboratories around the world, is the only method that distinguishes these species. For the purpose of our studies, zymodeme analysis represents the "gold standard". The results of our clinical evaluations show that the E. histolvica II exhibits a correlation of >97% when compared with zymodeme analysis, and that it is more sensitive than the E. histolytica Test for detecting E. histolytica trophozoites and adhesin. Our findings demonstrate that the test is useful for the detection of pathogenic E. histolytica in stool specimens.

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Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized depiction of an eagle with three curved lines representing its wings. The eagle is positioned above the acronym "HHS". The text "OF HEALTH & HUMAN SERVICES - USA" is arranged in a semi-circle above the eagle.

Food and Drug Administration 2098 Gaither Road Rockville MD 20850

DEC 2 1 1999

David M. Lyerly, Ph.D. Vice President TechLab. Inc. VPI Research Park 1861 Pratt Drive, Suite 1030 Blacksburg, Virginia 24060-6364

Re: K994101 Trade Name: E. histolytica II Regulatory Class: II Product Code: KHW Dated: November 22, 1999 Received: December 6, 1999

Dear Dr. Lyerly:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we 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). 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.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will veify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Eederal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal Javs or regulations.

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Page 2

Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA-88), this device may require a CLIA complexity categorization. To determine if it does, you should contact the Centers for Disease Control and Prevention (CDC) at (770)488-7655.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4588. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its to lifee number (800) 638-2041 or at (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html"

Sincerely yours,

Steven Autman

Steven I. Gutman, M.D., M.B.A. Director Division of Clinical Laboratory Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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K 494101

Page__________________________________________________________________________________________________________________________________________________________________________

510(k) Number (if known):_____________________________________________________________________________________________________________________________________________________ E. histolytica II

Device Name:_

Indications For Use:

The E. histolytica II is an enzyme immunoassay for the rapid detection of the adhesin of E. histolytica in human fecal specimens. It is indicated for use with fecal
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histolytica gastrointestinal infection. The test can becases miss not a routine clinical testing from adults or children. Conventional microscopy is not a
routine clinical testing from adults or children. Conventional microscopy is not a
routine prerequisite for use of the test. FOR IN VITRO DIAGNOSTIC USE.

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Concurrence of CDRH, Office of Device Evaluation (ODE)
Wordy Dators
(Division Sign/Off)
Division of Clinical Laboratory Devices
510(k) Number	K994101
Prescription Use	OR	Over-The-Counter Use
(Per 21 CFR 801.109)		(Optional Format 1-2-96)

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Regulation Number and Section

§ 866.3220

Entamoeba histolytica serological reagents.(a)
Identification. Entamoeba histolytica serological reagents are devices that consist of antigens and antisera used in serological tests to identify antibodies toEntamoeba histolytica in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye (immunofluorescent reagents) used to identifyEntamoeba histolytica directly from clinical specimens. The identification aids in the diagnosis of amebiasis caused by the microscopic protozoan parasiteEntamoeba histolytica and provides epidemiological information on diseases caused by this parasite. The parasite may invade the skin, liver, intestines, lungs, and diaphragm, causing disease conditions such as indolent ulcers, an amebic hepatitis, amebic dysentery, and pulmonary lesions.(b)
Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 866.9.