Model Number 441772 |
Device Problem
False Positive Result (1227)
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Patient Problem
Insufficient Information (4580)
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Event Date 10/24/2022 |
Event Type
malfunction
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Manufacturer Narrative
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H6.Investigation summary: the complaint investigation for discrepant results when using the bd max gbs (ref.(b)(4)) lots 1293472 and 2203772 was performed by the review of manufacturing records, analysis of the customer¿s data and verification of the complaints history.Review of manufacturing records of the bd max gbs indicated that lots 1293472 and 2203772 were manufactured according to specifications and met performance requirements.Customer complained about discrepant results when using the bd max¿ gbs assay which were negative upon culture, as well as when tested on another pcr platform (revogene) and on a bd max¿ from another hospital.Customer suspected interference from enterobacter cloacae as a potential cause of their issue.However, presence of enterobacter cloacae can potentially inhibit gbs detection at low concentration levels and, as such, it is not expected to lead to false positive results (see details in package insert (pi) p0091 in limitations of the procedure and interfering substances sections).Therefore, interference from enterobacter cloacae is not suspected of being the cause of the customer¿s potential false positive results issue.Customer provided database from instrument ct1896, run files 3058, 3158, 3199, 3386 and 3439 and a detailed table identifying affected samples in positions a7 (run 3058), a1 (run 3158), a5 (run 3199), a3 (run 3386) and b4 (run 3439) for investigation.Manual pcr curve adjudication of discrepant samples was performed.Pcr curves analysis showed that samples a7 (run 3058), a1 (run 3158), a3 (run 3386) and b4 (run 3439) all obtained late amplification of the gbs target (ct >30), which is unexpected with the bd max¿ gbs assay, since samples are tested following an enrichment step, consequently generating strong positive results.The most probable cause for the customer¿s discrepant results is suspected of being environmental contamination introduced during the sample preparation at the customer¿s site.This could explain the discrepant results obtained between the bd max¿ gbs assay and culture or repeat tests for two samples a3 (run 3386) and b4 (run 3439) with another platform (revogene) and a bd max¿ from another hospital.No repeat test of affected sample, with a new sbt, was found in the database provided.For sample a5 (run 3199), pcr curves analysis revealed a ct of 24.5, which would suggest a true positive result since it is similar to results from other positive controls used by the customer.Although bd is unable to identify the cause for this discrepancy with culture, a positive result does not necessarily indicate the presence of viable organisms in a sample, as stated in the assay package insert (pi;p0091), which could explain why culture results were negative.Finally, the customer also questioned the results obtained for samples b4 (analyzed previously) and b1 in run 3439, since both curves had similar shapes.Curves analysis revealed that in run 3439, both samples obtained late amplification of the gbs target, but only sample b4 had a valid ct value between 0 ct=37 to report a positive result (see details in p0091 table 1).This explains the different results obtained for both samples.Nevertheless, manual curve adjudication has limitations; visual examination of pcr curves for low signal is a conservative assessment of the data.There is no indication of a reagent issue based on the analysis of the complaints received for discrepant results on bd max gbs lots 1293472 and 2203772.The root cause was not identified.However, environmental contamination introduced during the sample preparation at the customer¿s site can 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 a preventive action plan since no new hazard was identified.Bd apologizes for the inconvenience that this may have caused.Bd quality will continue to monitor for trends.H3 other text : see h.10.
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Event Description
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Report 5 of 5 it was reported that bd max¿ gbs there has been a 50% increase positivity rate and have some possible false positives.No patient impact was reported.The following information was provided b y the initial reporter: we are questioning potential false positive results on the gbs assay.We have an almost 50% positivity rate with a high incidence of discrepant results between our max instrument, culture, revogene and another max instrument at a different hospital.
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Manufacturer Narrative
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The following fields have been updated with corrected and/or additional information.B.1.Adverse event b.2.Event attributed to: patient was given prophylactic treatment.Outcome unknown.H6: investigation summary the complaint investigation for discrepant results when using the bd max gbs (ref.(b)(4)) lots 1293472 and 2203772 was performed by the review of manufacturing records, analysis of the customer¿s data and verification of the complaints history.Review of manufacturing records of the bd max gbs indicated that lots 1293472 and 2203772 were manufactured according to specifications and met performance requirements.Customer complained about discrepant results when using the bd max¿ gbs assay which were negative upon culture, as well as when tested on another pcr platform (revogene) and on a bd max¿ from another hospital.Customer suspected interference from enterobacter cloacae as a potential cause of their issue.However, presence of enterobacter cloacae can potentially inhibit gbs detection at low concentration levels and, as such, it is not expected to lead to false positive results (see details in package insert (pi) p0091 in limitations of the procedure and interfering substances sections).Therefore, interference from enterobacter cloacae is not suspected of being the cause of the customer¿s potential false positive results issue.Customer provided database from instrument ct1896, run files 3058, 3158, 3199, 3386 and 3439 and a detailed table identifying affected samples in positions a7 (run 3058), a1 (run 3158), a5 (run 3199), a3 (run 3386) and b4 (run 3439) for investigation.Manual pcr curve adjudication of discrepant samples was performed.Pcr curves analysis showed that samples a7 (run 3058), a1 (run 3158), a3 (run 3386) and b4 (run 3439) all obtained late amplification of the gbs target (ct >30), which is unexpected with the bd max¿ gbs assay, since samples are tested following an enrichment step, consequently generating strong positive results.The most probable cause for the customer¿s discrepant results is suspected of being environmental contamination introduced during the sample preparation at the customer¿s site.This could explain the discrepant results obtained between the bd max¿ gbs assay and culture or repeat tests for two samples a3 (run 3386) and b4 (run 3439) with another platform (revogene) and a bd max¿ from another hospital.No repeat test of affected sample, with a new sbt, was found in the database provided.For sample a5 (run 3199), pcr curves analysis revealed a ct of 24.5, which would suggest a true positive result since it is similar to results from other positive controls used by the customer.Although bd is unable to identify the cause for this discrepancy with culture, a positive result does not necessarily indicate the presence of viable organisms in a sample, as stated in the assay package insert (pi;p0091), which could explain why culture results were negative.Finally, the customer also questioned the results obtained for samples b4 (analyzed previously) and b1 in run 3439, since both curves had similar shapes.Curves analysis revealed that in run 3439, both samples obtained late amplification of the gbs target, but only sample b4 had a valid ct value between 0 ct=37 to report a positive result (see details in p0091 table 1).This explains the different results obtained for both samples.Nevertheless, manual curve adjudication has limitations; visual examination of pcr curves for low signal is a conservative assessment of the data.There is no indication of a reagent issue based on the analysis of the complaints received for discrepant results on bd max gbs lots 1293472 and 2203772.The root cause was not identified.However, environmental contamination introduced during the sample preparation at the customer¿s site can 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 a preventive action plan since no new hazard was identified.Bd apologizes for the inconvenience that this may have caused.Bd quality will continue to monitor for trends.H3 other text : see h.10.
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Event Description
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It was reported that bd max¿ gbs there has been a 50% increase positivity rate and have some possible false positives.No patient impact was reported.The following information was provided b y the initial reporter: we are questioning potential false positive results on the gbs assay.We have an almost 50% positivity rate with a high incidence of discrepant results between our max instrument, culture, revogene and another max instrument at a different hospital.
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Search Alerts/Recalls
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