(104 days)
This microwell enzyme linked immunoabsorbant assay (ELISA) detection kit is an in vitro diagnostic (IVD) immunoassay for the detection of Cryptosporidium antigen in human feces using peroxidase as the enzyme. The assay may be read visually or with an ELISA reader. This IVD assay is intended to be used with stools that are fresh, frozen or preserved in 10% formalin, SAF or Medical Chemical Corporation's (MCC) Universal fixative. Concentrated samples cannot be used with this IVD.
This microwell enzyme-linked immunoabsorbant assay (ELISA) detection kit (Cryptosporidium ELISA Kit) is an in vitro diagnostic (IVD) immunoassay for the detection of antigen to Cryptosporidium species in human feces using peroxidase as the indicator enzyme. The assay may be read visually or with an ELISA reader. Concentrated fecal samples cannot be used with this immunoassay. Rather, this IVD Cryptosporidium ELISA Kit is intended to be used with human stools that are fresh, frozen or preserved in 10% formalin, SAF or Medical Chemical Corporation's (MCC's) Universal fixative in a clinical laboratory use setting.
This ELISA is an in vitro immunoassay for the qualitative determination of Cryptosporidium species antigen in feces. The ELISA uses a rabbit anti-Cryptosporidium antibody to capture the antigen from the stool supernatant. A second goat anti-Cryptosporidium antibody is then added which sandwiches the captured antigen. This reaction is visualized by the addition of an anti-second antibody conjugated to peroxidase and the chromogen tetramethylbenzidine (TMB). The resulting blue color development indicates the presence of Cryptosporidium species antigens being bound by the anti-Cryptosporidium antibodies.
Here's an analysis of the acceptance criteria and study details for the IVD Research Inc.'s Cryptosporidium Human Fecal Antigen Detection Microwell ELISA Kit, based on the provided text:
Acceptance Criteria and Device Performance
The acceptance criteria are implied by the performance metrics reported for comparison to the gold standard and the predicate device. For diagnostic tests, this generally includes high sensitivity, specificity, and agreement rates.
| Performance Metric | Acceptance Criteria (Implied) | Reported Device Performance |
|---|---|---|
| Study #1 (Outside Lab) vs. O&P Microscopy | Sensitivity ≥ 90% (e.g., comparable to predicate and gold standard) | Sensitivity: 100% (24/24) |
| Specificity ≥ 90% (e.g., comparable to predicate and gold standard) | Specificity: 97% (146/150) (95% CI: 93% to 99%) | |
| Study #2 (Manufacturer Performed) vs. Commercial ELISA | Positive Agreement ≥ 90% (e.g., similar to predicate) | Positive Agreement: 100% (14/14) |
| Negative Agreement ≥ 90% (e.g., similar to predicate) | Negative Agreement: 100% (30/30) | |
| Analytical Sensitivity | Detection of Cryptosporidium antigen at relevant clinical levels | Approximately 50 nanograms of soluble protein per ml of Cryptosporidium species antigen or 10 oocysts per well (OD range of 0.15 to 0.30) |
| Cross-Reactivity | No significant cross-reactivity with common fecal pathogens | No cross-reactions seen with a detailed list of 24 other organisms (parasites, bacteria) and 29 additional bacterial species. |
Study Details
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Sample Size used for the test set and the data provenance:
- Study #1 (Outside Lab): 174 human fecal specimens (formalin, SAF, fresh/frozen and Universal Fixative preserved stools). Data provenance is from "clinical laboratories or in-house collections," making it retrospective. The country of origin is not explicitly stated but is implied to be the US, given the FDA submission.
- Study #2 (Manufacturer Performed): 44 fresh or fresh/frozen human fecal specimens. Data provenance is from "clinical laboratories or in-house collections," making it retrospective. The country of origin is implied to be the US.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- The document does not specify the number of experts or their qualifications for establishing the ground truth (O&P microscopy results or other commercial ELISA results). It only refers to "O&P microscopy" as the "gold standard for parasitology" and "another commercial ELISA."
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Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- The document does not describe any specific adjudication method for the ground truth. It simply states that the results were interpreted against O&P microscopy or another commercial ELISA.
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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, a multi-reader multi-case (MRMC) comparative effectiveness study was not performed. This is an ELISA kit, not an AI-assisted diagnostic tool for human readers.
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If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Yes, this is effectively a standalone diagnostic device. The ELISA kit itself provides the qualitative determination. While a human reads the results (visually or with an ELISA reader), the performance metrics reported are for the kit's ability to detect the antigen, independent of human interpretive variability beyond simply reading a color change or optical density.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For Study #1, the ground truth was O&P (Ova and Parasite) microscopy, considered the "gold standard for parasitology."
- For Study #2, the ground truth was O&P microscopy and/or another commercial ELISA.
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The sample size for the training set:
- The document does not explicitly mention a "training set" in the context of machine learning or algorithm development. This refers to an ELISA kit, not an AI model. The studies described are validation (test) sets.
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How the ground truth for the training set was established:
- Given that this is an immunoassay kit and not an AI/machine learning device, there isn't a "training set" in the conventional sense. The "ground truth" for the test sets was established by O&P microscopy or a commercial ELISA, as described above.
§ 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.