BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    XPERT C. DIFFICILE BT

    MDR report key: 22777165 · Received August 11, 2025

    Report

    Report Number
    3004530258-2025-00023
    Event Type
    Malfunction
    Date Received
    August 11, 2025
    Date of Event
    July 24, 2025
    Report Date
    September 10, 2025
    Manufacturer
    CEPHEID AB
    Product Code
    LLH
    PMA / PMN Number
    K091109
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    FR
    Reporter Occupation
    PHYSICIAN
    Health Professional
    Yes

    Narratives

    Additional Manufacturer Narrative · 0

    ON 01-AUG-2025, STOOL WAS SENT BY THE LABORATORY TO THE NATIONAL REFERENCE LABORATORY (NRL) FOR CULTURE AND INVESTIGATION. RESULTS SHOWED NO CLOSTRIDIOSES DIFFICILE IN THE STOOL. NO PATIENT HARM REPORTED AS THE TREATMENT WAS STARTED BEFORE THE RESULT WAS AVAILABLE AND RELIED ON THE FIA TEST, REGARDLESS OF THE PCR RESULT. IN CONCLUSION, THE DISCREPANCY IS DUE TO A FALSE POSITIVE OF THE FIA TEST, WHICH HAS BEEN REPORTED PREVIOUSLY IN THE LABORATORY AND IN SCIENTIFIC LITERATURE. XPERT C. DIFFICILE BT ASSAY PERFORMED AS INTENDED AND NO MALFUNCTION WAS IDENTIFIED. THE LIKELY ROOT CAUSE IS THEREFORE AN INHERENT DIFFERENCE IN THE TEST METHODS. THEREFORE, THE CASE IS DEEMED NOT REPORTABLE.

    Additional Manufacturer Narrative · 0

    A LIQUID STOOL SAMPLE WAS COLLECTED ON (B)(6) 2025 FROM A PATIENT HOSPITALIZED IN A MEDICAL WARD WITH PREVIOUS HISTORY OF CDI (CLOSTRIDIOIDES DIFFICILE INFECTION) IN THE PAST MONTHS. THE SAMPLE WAS TESTED ON SOFIA 2 C DIFFICILE FIA (FLUORESCENT IMMUNOASSAY BY QUIDEL) AND XPERT C DIFFICILE ON THE SAME DAY AND GAVE A POSITIVE RESULT FOR GDH AND TOXIN, BUT NEGATIVE PCR RESULT. WITHOUT WAITING FOR THE RESULTS, THE PATIENT WAS TREATED FOR CDI (USING THE FIA TEST RESULTS) AND IMPROVED. STOOL WAS PROCESSED ACCORDING TO THE IFU AND GAVE AN INVALID RESULT UPON FIRST TEST DUE TO SPC FAILURE (ALL OTHER TARGETS CURVES WERE FLAT). TEST WAS REPEATED 3 TIMES AND GAVE 3 NEGATIVE RESULTS WITH SPC CYCLE THRESHOLD/ FLUORESCENCE (CT/FLUO) VALUES OF=31.5/29, 31.8/37 AND 33.3/23. EXCEPT HIGH CT VALUES AND LOW FLUORESCENCE, THE CURVES LOOK NORMAL. SOFIA 2 C DIFF FIA (QUIDEL) WAS POSITIVE FOR GHD AND TOXINS A/B. ON (B)(6) 2025, STOOL WAS SENT BY THE LABORATORY TO THE NATIONAL REFERENCE LABORATORY (NRL) FOR CULTURE AND INVESTIGATION. THE RESULTS ARE PENDING. NO PATIENT HARM REPORTED AS THE TREATMENT WAS STARTED BEFORE THE RESULT WAS AVAILABLE AND RELIED ON THE FIA TEST, REGARDLESS OF THE PCR RESULT. THE STOOL DID NOT EXHIBIT A MUCOID APPEARANCE OR ANY SPECIFIC CHARACTERISTICS. AT THIS STAGE, CEPHEID IDENTIFIED THREE POSSIBLE ROOT CAUSES FOR THE DISCREPANCY: A FALSE POSITIVE FIA RESULT WHICH HAS BEEN REPORTED PREVIOUSLY IN THE LABORATORY AND IN THE SCIENTIFIC LITERATURE. A LOW BACTERIAL LOAD BELOW THE DETECTION THRESHOLD FOR C DIFFICILE IN A CONTEXT OF PCR INHIBITOR AS HYPOTHESIZED BY THE SPC VALUES, OR: A MUTATION IN THE PRIMER BINDING REGION OF THE TOXIN B GENE. THE INVESTIGATION IS STILL ONGOING: CEPHEID ASKED THE CUSTOMER TO PROVIDE THE RESULTS FROM THE NRL. A SUPPLEMENTAL REPORT WILL BE SUBMITTED ONCE ADDITIONAL INFORMATION IS RECEIVED. NOTE FOR SECTION H3 DEVICE EVALUATED BY MANUFACTURER - ANSWER OF NO IS DUE TO THE SINGLE USE OF THE XPERT C. DIFFICILE BT TEST AND THE UNAVAILABILITY OF THAT PRODUCT LOT TO BE RETURNED TO CEPHEID.

    Description of Event or Problem · 0

    ON (B)(6) 2025, THE CUSTOMER CONTACTED TECHNICAL SUPPORT TO REPORT A QUESTIONABLE NEGATIVE RESULT FROM THE XPERT C. DIFFICILE BT TEST. ON (B)(6) 2025, A STOOL SAMPLE WAS COLLECTED FROM A SYMPTOMATIC PATIENT IN A STERILE CONTAINER. THE SAMPLE WAS TESTED USING THE XPERT C. DIFFICILE BT (BACTERIAL TOXIN) METHOD, FOLLOWING RECOMMENDED INSTRUCTIONS. THE INITIAL TEST RESULT WAS REPORTED AS INVALID AND COMMUNICATED TO THE PHYSICIAN. LATER THE SAME DAY, THE SAMPLE WAS RETESTED USING THE SAME LOT NUMBER: (37705). THE RESULT WAS: TOXIGENIC C. DIFFICILE NEGATIVE, BINARY TOXIN NEGATIVE, AND STRAIN 027 NEGATIVE. THIS RESULT WAS ALSO REPORTED TO THE PHYSICIAN. ADDITIONALLY, ON (B)(6) 2025, A GDH (GLUTAMATE DEHYDROGENASE) AND TOXIN ANTIGENIC TEST WAS PERFORMED ON THE SAME SAMPLE USING THE SOFIA 2 METHOD. THE RESULT WAS POSITIVE FOR BOTH GDH (GLUTAMATE DEHYDROGENASE) AND TOXIN. ON (B)(6) 2025, THE SAMPLE WAS RETESTED TWICE USING XPERT C. DIFFICILE BT, SAME LOT 37705. BOTH TESTS YIELDED THE SAME RESULT: TOXIGENIC C. DIFFICILE NEGATIVE, BINARY TOXIN NEGATIVE, AND STRAIN 027 NEGATIVE. THESE RESULTS WERE REPORTED TO THE PHYSICIAN. THE PATIENT WAS ULTIMATELY DIAGNOSED AS POSITIVE. THE CUSTOMER SUSPECTS THE PRESENCE OF AN INHIBITOR IN THE SAMPLE THAT MAY HAVE CAUSED THE DISCREPANCY. NO HARM WAS REPORTED TO THE PATIENT. THE CUSTOMER REQUESTED FURTHER INFORMATION REGARDING POSSIBLE CAUSES OF THE DISCREPANCY.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    2109833 XPERT C. DIFFICILE BT XPERT C. DIFFICILE BT TEST LLH CEPHEID AB 1001470896

    Patients

    Seq Age Sex Outcome Treatment
    1 NA Unknown