[86257887]
The customer, (b)(6) at (b)(6), obtained a patient isolate at the end of (b)(6). The patient sample was grown on a mycobacteria growth indicator tube (mgit) and the smear was acid-fast bacilli (afb) positive and exhibited "dragon" cording, consistent with mycobacterium tuberculosis complex (mtbc) morphology. The customer tested the patient sample using hologic's accuprobe mycobacterium tuberculosis complex culture identification test and twice obtained a negative result. Customer stated they are confident this patient has tuberculosis. The run results were reviewed by hologic, which demonstrated that the control values were strong and that there were other positive samples in the run obtained by the customer. The customer retested the original specimen using the cepheid genexpert mtb/rif assay and found the specimen to be mtbc-positive. The genexpert mtb/rif assay is a newer generation system that uses real-time polymerase chain reaction (pcr) to amplify the target dna strands for detection, while the accuprobe system is a non-amplified detection system. Combined, these data suggests that the accuprobe mtbc test potentially gave a false negative result. Additional samples taken from the same patient resulted in positive results using the accuprobe mtbc kit. Per preliminary risk assessment, several factors that may contribute to obtaining a false negative result using the accuprobe mtbc assay. These include: a manufacturing defect, a compromised kit due to storage at the customer site, or samples that have been improperly prepared. There have been no other similar complaints for the same lot in the last 12 months. The original sample was returned to hologic and will be investigated under (b)(4). A final risk assessment will be performed following the investigation.
Patient Sequence No: 1, Text Type: D, B5