[16613884]
The kit (96 tests per kit) has been in use in rptr's lab for one yr to assay for clostridium difficile toxin. Initial comparison with tissue culture cytotoxicity showed 100% sensitivity and specificity. A problem was suspected in 3/94, because rptr had an increase in the number of indeterminate results, which previously had always turned out to be positive by cytotoxin assay. In addition, the infection control office had investigated some positive results and found them to be inconsistent with c difficile diarrhea. Below is a summary of lab data, indicating that falsely-positive results occurred with two lots. Rptr repeatedly informed the co of the erroneous results between march and july. They first denied a problem with the kit and later stated that they had some other complaints and would send rptr a new lot number. Until the new kit came on 7/20/94, many of the toxin assay results had to be confirmed by cytotoxicity. The new lot # arrived 7/20/94, and the first kit put into use had similar problems to the previous lot. The second kit was opened and worked accurately. Data for this lot can be provided. Rptr discontinued use of the test kit on 8/1. Mfr agrees that there are a large number of indeterminate results with some kits but the number of kits with the problem is very low. Previously, they noted that bloody stools can give falsely-positive results, although this statement is not in the package insert. For these reasons, they do not think that it's necessary to recall the lot numbers. Rptr disagrees. The number of pts who have been treated with antimicrobial agents and the amount of technologist and infection control practitioner time used to deal with assays with indeterminate and false-positive results has been costly to the healthcare system. Rptr recommends the recall of the lot numbers. (*)
Patient Sequence No: 1, Text Type: D, B5