ALINITY M STI AMP KIT

Additional Manufacturer Narrative

AN INVESTIGATION IS IN PROCESS. A FOLLOW-UP REPORT WILL BE SUBMITTED WHEN THE INVESTIGATION IS COMPLETE. THIS INCIDENT IS BEING REPORTED TO FDA BECAUSE THE INCIDENT OCCURRED INTERNATIONALLY USING THE ALINITY M STI ASSAY, LIST NUMBER 09N17-091, WHICH IS THE SAME/ SIMILAR TO THE ALINITY M STI ASSAY, LIST NUMBER 09N17-095, WHICH RECEIVED FDA APPROVAL.

Description of Event or Problem

THE CUSTOMER REPORTED A FALSE NEGATIVE RESULT WHILE RUNNING THE ALINITY M STI ASSAY. THE CUSTOMER REPORTED ONE PATIENT SAMPLE ID (SID) (B)(6) REPORTED WITHOUT A CYCLE THRESHOLD VALUE, WITH A VISIBLE AMPLIFICATION CURVE BUT RELEASED AS "NOT DETECTED" FOR THE TARGET CHLAMYDIA TRACHOMATIS (CT). TECHNICAL APPLICATION SPECIALIST (TAS) REVIEWED LOG FILES. THE CURVE ANALYSIS REVEALED AMPLIFICATION TAKES PLACES AND CROSSES THRESHOLD AROUND CYCLE 35. THE RESULT INTERPRETATION IS "NOT DETECTED". TAS CHECKED THE CUTOFF CRITERIA OF THE CYCLE THRESHOLD VALUE AND THE MR-VALUE (MAX RATIO) FOR THE CT TARGET OF THE STI ASSAY (09N17-91). THE SAMPLE CYCLE NUMBER CUTOFF FOR CT IS CYCLE 39 WHICH MEANS THE REQUIREMENTS ARE MET AND THE SID IS WITHIN THE CUTOFF. THE SAMPLE TARGET MINIMUM MR REQUIREMENT FOR SAMPLES >CN 6 FOR THE CT TARGET IS (B)(4). THE MR VALUE FOR THE AFFECTED SID IS (B)(4), THEREFORE NOT MEETING THE MR VALUE REQUIREMENTS. TAS EXPLAINED TO CUSTOMER THAT THE RESULT "NOT DETECTED" IS NO MISTAKE, BUT CORRECT BECAUSE THE SAMPLE DOES NOT MEET THE MR VALUE REQUIREMENT. THE SAMPLE WAS RE-TESTED USING AN ALTERNATE PLATFORM, WHICH YIELDED A POSITIVE RESULT FOR *C. TRACHOMATIS* WITH A CYCLE THRESHOLD VALUE OF 36. THE RESULT "C. TRACHOMATIS DETECTED" WAS REPORTED TO THE ORDERING PHYSICIAN. THERE WAS NO REPORT OF IMPACT TO PATIENT MANAGEMENT.