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It was reported that during use of bd max¿ check-points (cpo), a false positive verona integron-encoded metallo-b-lactamase (vim) patient result with an unusual pcr curve was obtained.Culture was positive, and immunochromatography showed vim.There was no report of patient impact.
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Investigation summary: the complaint investigation for suspected false positive results when using bd max¿ cpo (ref.(b)(4)) kit lot 5044761 was performed by the review of manufacturing records, retain material testing, review of customer¿s data and by the complaint¿s history review.Review of the manufacturing records of bd max¿ cpo indicated that lot 5044761 was manufactured according to specifications and met performance requirements.No anomalies were observed in manufacturing record that could explain the customer¿s negative results.The retain material of bd max¿ cpo from lot 5044761 was tested and the results were as expected.Customer complained about one of their samples (last three digits of accession number #201) presented a positive curve in the vic channel (vim/imp-1-2 targets), but the software interpreted the result as negative.According to customer, this is an issue with the interpretation of a positive result.They cultured the sample, which tested positive and immunochromatography detected vim.One of the pictures provided for the investigation revealed a pcr amplification curve with a late ct value.Despite the signal in the vic channel (vim/imp-1-2 targets), the result was negative because the signal did not reach the threshold, to be considered valid by the algorithm.Again, a high ct value for the vim /imp-1-2 target suggests that this sample was at a very low bacterial or dna concentration, below the assay¿s limit of detection for the vim target, explaining the negative vim/imp-1-2 result.As stated in the assay instruction for use ¿limitations of the procedure¿ section, the bd max¿ system provides qualitative results.Any reported ct value or displayed curve should only be used for the purposes of laboratory quality control trending, research, and public health reporting.A negative result was the expected result in such condition.It must also be noted that limit of detection can vary between different assays and testing methods.Based on the investigation and information provided, no reagent issue is suspected.There is no indication of a reagent issue based on the analysis of the complaints received for discrepant results on bd max¿ cpo kit lot 5044761.The root cause was not identified.However, a sample at or near the assay limit of detection (lod) is the most likely cause to explain the customer¿s discrepant results.Bd cannot confirm the complaint based on the investigation that was performed.Bd did not initiate a corrective and preventive action since no new hazard was identified.
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It was reported that during use of bd max¿ check-points (cpo), a false positive verona integron-encoded metallo-b-lactamase (vim) patient result with an unusual pcr curve was obtained.Culture was positive, and immunochromatography showed vim.There was no report of patient impact.
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