Catalog Number 09203079190 |
Device Problem
False Negative Result (1225)
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Patient Problem
No Clinical Signs, Symptoms or Conditions (4582)
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Event Date 05/26/2022 |
Event Type
malfunction
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Event Description
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The initial reporter stated they received questionable negative results for seven patient samples tested with elecsys anti-sars-cov-2 on a cobas 8000 e 801 module (serial number (b)(4)).No incorrect results were reported outside of the laboratory.All seven patients had a history of covid-19 infection.All patients had positive polymerase chain reaction (pcr) test results 11 to 42 days prior to testing the patients with the elecsys anti-sars-cov-2 assay.The specific information/data for each patient/sample was not provided.For each individual patient, it is not known exactly how many days elapsed between pcr and elecsys anti-sars-cov-2 measurements.When tested on the e 801 analyzer, all seven samples had non-reactive results for elecsys anti-sars-cov-2.The results ranged between 0.3 coi and 0.9 coi.The reporter noted that the coi values for these measurements were higher than the coi for other negative samples, so a high dose hook effect was suspected.
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Manufacturer Narrative
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Per product labeling: "the sensitivity of the elecsys anti-sars-cov-2 assay early after infection is unknown.Negative results do not preclude acute sars-cov-2 infection.If acute infection is suspected, direct testing for sars-cov-2 is necessary." the investigation could not identify a product problem.A possible explanation would be that antibody titers have not yet developed to a detectable level in the elecsys anti-sars-cov-2 assay.The result distribution would be in line with this assumption as some individuals have shown enhanced, but non-reactive levels just below the cutoff value of 1 coi (range = 0.3-0.9 coi).Anti-nucleocapsid antibodies may also have a lower sensitivity in m-rna-vaccinees who later become infected.
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Manufacturer Narrative
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The component code has been updated.
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Search Alerts/Recalls
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