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Investigation: (b)(6) reported a discrepant meca result on the filmarray bcid panel after testing a blood sample from a (b)(6) year old, male patient.The patient is a diabetic and alcoholic, and at the time of sample collection (date unknown), the patient was critically ill with acute kidney injury (aki) (scr was 6.83 mg/dl with a baseline of 0.85 mg/dl).The patient was not on antimicrobial treatment at the time of sample collection.The sample was cultured using a bact/alert sa bottle (lot# 1052254; expiration date october 17, 2019).The sample was tested on the filmarray bcid panel on (b)(6) 2019, and the result was (b)(6) for enterococcus, streptococcus, (b)(6), and meca.Based on the filmarray bcid panel result, the patient was treated with vancomycin.On (b)(6) 2019, the sample was tested again on the filmarray bcid panel.The result was the same as the first filmarray bcid panel test: (b)(6) for enterococcus, streptococcus, (b)(6), and meca.A gram stain was performed using the sample and resulted in gram positive cocci.A culture was also performed using the sample and the culture grew enterococcus faecalis, streptococcus species, and (b)(6).The (b)(6) was identified by a manual coagulase test and mic was performed on vitek.The mic results reported (b)(6).The vancomycin treatment was discontinued after the culture results were available.Due to the filmarray bcid result, the customer reported that the patient was on vancomycin unnecessarily for several days (exact timeframe unknown).The customer stated that the unnecessary treatment "likely did not help" the patient's condition, and thus may have caused the patient harm.Based on the information submitted, it cannot be determined if the vancomycin was responsible for the injury, or increased the severity of the injury, and if the positive blood cultures were clinically significant or should have been considered as contaminated.Biofire has reached out to the customer to request additional information regarding this case.Quality control (qc) records for both the initial and repeat filmarray bcid panel tests (pouch lot# 381218 and kit lot# 0500618) were reviewed.This pouch lot passed the qc criteria and was found within specifications.No run malfunction was observed and the filmarray instrument (serial # (b)(4)) was working within design specifications.Conclusion: based on the information provided at this time, the investigation concluded that the most likely cause for the discrepant filmarray bcid panel meca result is differences in sensitivity between the filmarray bcid panel and comparator methods.(b)(6) can be a heterogeneous population consisting of both (b)(6).(b)(6) can be missed when only a single colony or only a few colonies are selected for antimicrobial susceptibility testing.The sample could also contain slow-growing strains of (b)(6) that required extended incubation to detect the presence of (b)(6).Additionally, as per vitek2 product recall notice (#z-2817-2018), it is advised to use the bioart rule and do additional confirmatory testing by either meca pcr or pbp2a testing.The filmarray bcid panel reports detections from the blood culture population, while vitek and manual coagulase testing report detections from a single/few isolated colonies.Additionally, the results for the filmarray bcid panel antimicrobial resistance gene assays do not specifically link the resistance gene to the associated organism.Specifically, in mixed growth, the filmarray bcid panel does not attribute meca-mediated (b)(6) to either (b)(6) or other staphylococcus species.Therefore, the positive meca result on the filmarray bcid panel could be due to multiple staphylococcus organisms present in the sample.During panel performance evaluation, the bcid meca assay showed robust performance as compared to pcr/sequencing of cultured isolates of (b)(6), with a sensitivity of 98.5% (ci 91.7-100%) and a specificity of 95.6% (ci 87.6-99.1%) for prospective fresh specimens.When compared with phenotypic automated ast testing, the bcid meca assay performed well in samples containing (b)(6) with a ppa of 97.7% (ci 93.4-99.5%) and npa of 96.7% (ci 91.7-99.1%) (bcid panel instruction booklet [https://www.Online-ifu.Com/iti0045]).It is important to note that the filmarray bcid panel is indicated as an aid in the diagnosis of specific agents of bacteremia and fungemia, and results should be used in conjunction with other clinical and laboratory findings.It is also important to note that the performance of the filmarray bcid panel has not been evaluated specifically on immunocompromised patients (bcid panel instruction booklet [https://www.Online-ifu.Com/iti0045]).
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(b)(6) reported a discrepant meca result on the filmarray blood culture identification (bcid) panel after testing a blood sample from a (b)(6) year old, immunocompromised, male patient.Due to the filmarray bcid result, the customer reported that the patient was given unnecessary treatment for several days.The customer also reported that the unnecessary treatment may have caused harm to the patient.Upon investigation, no malfunction occurred and the system was working within specifications.The investigation concluded the discrepancy was most likely caused by specificity differences between the filmarray bcid panel and comparator methods, possibly in combination with a sample contained a heterogenous population of resistant and susceptible staphylococci.
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Biofire received the following additional information from the clinical site regarding report.According to the customer, the patient lived and was hospitalized for 10 days, then transferred to a long-term acute care specialty hospital for ongoing iv antibiotic therapy and physical therapy.Renal function returned to normal (scr 0.6-0.8 mg/dl).At the time of treatment, the patient's liver function was scr 6.83 mg/dl.During treatment, the liver function remained elevated but improved to scr 1.77 by day 5 of vancomycin.Treatment was then de-escalated, and the patient's liver function continued to improve until normal (scr 0.6-0.8 mg/dl).The customer confirmed that the acute kidney injury (aki) was a pre-existing condition, and was not caused by the filmarray result.Based on the clinical data, the vancomycin did not appear to contribute to an increased severity since the serum creatinine levels actually decreased.Kidney function continued to improve after de-escalation of treatment; this may be related to the natural course of the recovery and not necessarily the discontinuation of the vancomycin.
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