Objective: To assess the diagnostic value of an adenosinetriphosphate bioluminescence assay (ATPmetry) to monitor the effectiveness of the reprocessing of endoscopes compared with microbiologic sampling.
Design: Diagnostic study.
Setting: A 2,200-bed teaching hospital performing 5,000 to 6,000 endoscopic procedures annually.
Inclusion criteria: All samples from bronchial or gastrointestinal endoscopes whatever the context.
Methods: Samples for microbiologic analysis and ATPmetry measurements were taken when each endoscope was inspected following reprocessing. Sampling was performed by flushing each endoscope with 300 mL Neutralizing Pharmacopeia Diluent thiosulfate rinsing solution divided equally between the endoscope channels. For each endoscope a series of 3 ATPmetry measurements were made on a vial containing the first jet from each channel and a second series on the whole sample.
Results: Of 165 samples from endoscopes, 11 exceeded the acceptability threshold of 25 colony-forming units/endoscope. In the first jet collected, the median (interquartile range) level of ATPmetry was 30.5 (15.3-37.7) relative light units (RLU) for samples with 25 or fewer colony-forming units compared with 37.0 (34.7-39.3) RLU for samples with more than 25 colony-forming units (P=.008). For the whole sample, the median (interquartile range) level of ATPmetry was 24.8 (14.3-36.3) RLU and 36.3 (36.0-38.3) RLU (P=.006), respectively. After adjusting on the batch of cleansing solution used, no difference in ATPmetry values was found between microbiologically acceptable and unacceptable samples.
Conclusion: ATPmetry cannot be used as an alternative or complementary approach to microbiologic tests for monitoring the reprocessing of endoscopes in France.